![](media/image1.wmf){width="5.607638888888889in" height="0.85in"}

**D-Zero Detector Central Fiber Tracker (CFT) Axial Project**

**Readout Electronics**

D0 Central Tracker Trigger (CTT) Mixer System

Backplane Description & Power Distribution Specification

Date: July 4, 2000

Revision Date: March 27^th^, 2003

**Stefano Rapisarda, Neal Wilcer, John Anderson**

**Document \# ESE-D0-000704**

Table of Contents

[1 Introduction 2](#introduction)

[2 Overview 3](#overview)

[Figure 1, Picture of the mixer subrack. 3](#__RefHeading___Toc36523638)

[Figure 2, Mixer System backplane 5](#__RefHeading___Toc36523639)

[3 Physical Attributes of the Backplane
6](#physical-attributes-of-the-backplane)

[3.1 Dimensions 6](#dimensions)

[3.2 Layer Description 6](#layer-description)

[Figure 3, Mixer Backplane Stackup 6](#__RefHeading___Toc36523643)

[3.3 Connectors 6](#connectors)

[3.4 Backplane to chassis mounting 6](#backplane-to-chassis-mounting)

[Figure 4. Front View of Mixer System Backplane
7](#__RefHeading___Toc36523646)

[Figure 5. Rear View of Mixer System Backplane
7](#__RefHeading___Toc36523647)

[3.5 DC power connections 7](#dc-power-connections)

[Figure 6. Backplane and Bus Bar Assembly
8](#__RefHeading___Toc36523649)

[Figure 7. Picture of Mixer Crate with Power Supplies.
8](#__RefHeading___Toc36523650)

[Figure 8. Picture of Bus Bar to Vicor Power Supply Connections.
9](#__RefHeading___Toc36523651)

[Figure 9. Picture of Mixer Subrack AC Terminal Block Connections
9](#__RefHeading___Toc36523652)

[3.6 AC Distribution 10](#ac-distribution)

[Figure 10, Schematic diagram of AC distribution box.
10](#__RefHeading___Toc36523654)

[Figure 11. Picture of Backplane Bus Bar Assembly
11](#__RefHeading___Toc36523655)

[Figure 12. Bus Bar Stud 11](#__RefHeading___Toc36523656)

[Figure 13. Backplane to Bus Bar Assembly
12](#__RefHeading___Toc36523657)

[Figure 14. Picture of section 1 of Bus Bar Assembly
12](#__RefHeading___Toc36523658)

[Figure 15. Mechanical Drawing of section 1 of Bus Bar Assembly
13](#__RefHeading___Toc36523659)

[Figure 16. Mounting Hardware for Bus Bar Assembly sections 1 and 2
13](#__RefHeading___Toc36523660)

[Figure 17. Picture of section 2 of Bus Bar Assembly
14](#__RefHeading___Toc36523661)

[Figure 18. Mechanical Drawing of section 2 of Bus Bar Assembly
14](#__RefHeading___Toc36523662)

[Figure 19. Picture of section 3 of Bus Bar Assembly
15](#__RefHeading___Toc36523663)

[Figure 20. Mechanical Drawing of section 3 of Bus Bar Assembly
15](#__RefHeading___Toc36523664)

[3.7 Torque Specs 16](#torque-specs)

[4 Power source 16](#power-source)

[5 Power requirements 16](#power-requirements)

[6 Analysis of Current Densities 16](#analysis-of-current-densities)

[Figure 21. Analysis of Current Densities; Areas of Interest
17](#__RefHeading___Toc36523669)

[Table 2. Single Leg of Bus Bar section 3 Cross Section
18](#__RefHeading___Toc36523670)

[Table 5. Bus Bar section 2 Cross Section
18](#__RefHeading___Toc36523671)

[Table 6. Bus Bar Section 2 to Bus Bar section 1
19](#__RefHeading___Toc36523672)

[Table 7. Bus Bar Section 1 Cross Section
19](#__RefHeading___Toc36523673)

[Table 8. Bus Bar section 1 to Spacer (also spacer to Backplane)
19](#__RefHeading___Toc36523674)

[Table 9. Backplane to Power/GND Plane (thru holes, vias)
19](#__RefHeading___Toc36523675)

[Figure 22. Side View of Through Hole 20](#__RefHeading___Toc36523676)

[Table 10. Power/GND Plane to Connector.
23](#__RefHeading___Toc36523677)

[7 Appendix A - Mixer System Backplane connectors pinout
26](#appendix-a---mixer-system-backplane-connectors-pinout)

[Table 11, Pin/Signal assignments for the backplane top section
connector 26](#__RefHeading___Toc36523679)

[Table 12, Pin/Signal assignments for the backplane bottom section
connector. 27](#__RefHeading___Toc36523680)

[8 References 28](#references)

# Introduction

This document describes the mixer system backplane. The mixer system is
part of the readout electronics of the D-Zero detector Central Fiber
Tracker (CFT) at Fermilab. More information on the experiments performed
at Fermilab is available on the laboratory web page:

<http://www.fnal.gov/>

More information on the D0 Detector is available on:

<http://www-d0.fnal.gov/>

The designers welcome suggestions and corrections \[Ref. 4\], which can
be addressed directly to the engineer responsible of the project.
Contact information is available on the Electronics System Engineering
(ESE) web page:

<http://www-ese.fnal.gov/>

More information and documentation on the Mixer Project are available
on:

<http://www-ese.fnal.gov/D0_CTT_MIXER/>

# Overview

The mixer system \[Ref 4\] consists of a 21 slots subrack with a custom
backplane. Slot 1 is occupied by a custom subrack controller, slot 2 to
slot 21 host twenty mixer boards. The mixer system is partitioned in
five subsystems of four boards each. The mixer system custom backplane
was developed as an interconnect and power distribution bus for the
mixer board set. It resembles the 6U VME J1/J2 backplane form, but does
not necessarily adhere to VME backplane specifications \[Ref. 2\].

![](media/image2.jpeg){width="5.385416666666667in" height="4.6875in"}

[]{#__RefHeading___Toc36523638 .anchor}Figure 1, Picture of the mixer
subrack.

Figure 2 shows a sketch of the mixer system backplane electrical
interconnections. The backplane schematic is available in a separate
document \[Ref.4\].

The backplane support the following interfaces:

***Subrack controller general-purpose bus interface.***

Used for configuration download and for remote access to the mixer
boards. More information about the Subrack Controller is provided in
separate documents \[Ref.4, 5e\].

***Subrack controller slow monitoring serial bus interface.***

During data acquisition, due to the proximity of the mixer system to
detector components, noise considerations suggest to avoid accessing the
mixer system over the \"general purpose bus interface\". The slow
monitoring serial bus provides a way to readback status information from
the mixer boards.

***Subrack controller 1553 interface.***

The subrack controller is remotely accessible through a MIL-STD-1553
serial bus. The MIL-STD-1553 is a networking standard used for
integration of military platforms \[Ref. 6\]. The backplane host the two
1553 triaxial connectors needed by the subrack controller to implement
the 1553 interface.

***Board to board buses.***

Mixer boards need to exchange part of the data they receive over the
input links with the adjacent boards belonging to the same mixer
subsystem (four boards). This is accomplished with two parallel buses 41
bit wide, one to the next backplane slot to the left and one to the next
backplane slot to the right.

***Timing signals distribution***

Out of a mixer subsystem (group of four boards) the leftmost is used as
\"master\" for distribution of global clock and global frame
synchronization (SYNC) signals to the other three boards (slaves). The
clock is distributed over three (one for each slave board)
point-to-point LVDS connections. The SYNC is distributed over three
point-to-point LVTTL connections.

***Power supply.***

A mixer board is powered through a backplane connection to the 3.3Volts
subrack power supply. A small brick power supply is used to provide 5
Volts power needed by the subrack controller (slot 1). Two green LEDs,
one for each supply voltage are ON when the backplane is powered. Three
polyfuses are used as over-current protection. Each mixer board has its
own over-current/over-voltage protection.

![](media/image3.wmf){width="6.291666666666667in"
height="8.385416666666666in"}

[]{#__RefHeading___Toc36523639 .anchor}Figure 2, Mixer System backplane

# Physical Attributes of the Backplane

## Dimensions 

The mixer system backplane is 16.910" \[429.514mm\] wide by 10.310"
\[261.874mm\] high. The thickness is .192" \[4.877mm\], it was
determined using a 8:1 aspect ratio of backplane thickness compared to
the smallest thru hole diameter (0.024" \[0.6096mm\]). The 8:1 aspect
ratio is the maximum allowable to assure even plating in thru holes.

## Layer Description

The backplane is fourteen layers thick. Top and bottom layers are 1 oz.
copper (thickness: .0014\" \[.0356mm\]) pours attached to digital
ground. Plated areas provide the option to connect these copper pours to
the earth ground (chassis). There are five inner signal layers, two
+3.3V layers, and five GND layers. Layer IN2 and IN4 have 100Ω
differential impedance and are used for clock signals with the
differential traces stacked in a broadside-coupled stripline fashion.
The remainder of the signal layers has 50 Ω impedance and the signal
traces are arranged in symmetrical stripline fashion. Figure 3 shows the
layers stackup.

![](media/image4.wmf)

[]{#__RefHeading___Toc36523643 .anchor}Figure 3, Mixer Backplane Stackup

## Connectors

Backplane connectors used for power distribution to the Mixer Boards and
signal lines are a combination of the A and B type 2mm hard metric
\[Ref. 7\]. These are press fit connectors. Each slot is keyed in two
places for guiding the mixer boards into the mixer system backplane.

## Backplane to chassis mounting

Standard VME spec backplane mounting is used. Figure 4 shows the front
side of the backplane, Figure 5 shows the rear of the backplane.

![](media/image5.jpeg){width="4.433333333333334in" height="3.325in"}

[]{#__RefHeading___Toc36523646 .anchor}Figure 4. Front View of Mixer
System Backplane

![](media/image6.jpeg){width="4.433333333333334in" height="3.325in"}

[]{#__RefHeading___Toc36523647 .anchor}Figure 5. Rear View of Mixer
System Backplane

## DC power connections

Power connections meet the "Electrical Design Standards for Electronics
to be used in Experiment Apparatus at Fermilab", rev 4.0, dated October
16 1998 \[Ref.3\]. The +3.3V supply and the GND return are attached to
the backplane via screws attached to the plated copper bus bar
assemblies. See Figure 6, Figure 7 and Figure 8.

![](media/image7.png){width="5.579166666666667in"
height="4.292361111111111in"}

[]{#__RefHeading___Toc36523649 .anchor}Figure 6. Backplane and Bus Bar
Assembly

![](media/image8.jpeg){width="5.386111111111111in"
height="4.039583333333334in"}

[]{#__RefHeading___Toc36523650 .anchor}Figure 7. Picture of Mixer Crate
with Power Supplies.

![](media/image9.jpeg){width="5.4in" height="4.054861111111111in"}

[]{#__RefHeading___Toc36523651 .anchor}Figure 8. Picture of Bus Bar to
Vicor Power Supply Connections.

![](media/image10.jpeg){width="5.486111111111111in"
height="4.114583333333333in"}

[]{#__RefHeading___Toc36523652 .anchor}Figure 9. Picture of Mixer
Subrack AC Terminal Block Connections

## AC Distribution

BiRa Systems \[Ref. 8\] built the AC distribution box to D0
specifications. It is a 3U x 19" rack mount unit with circuit breakers
on the front panel and AC sockets on the back side. Three phase AC is
supplied to the box, and is then distributed as two phase AC to the
power supplies. A dual receptacle single phase AC connection is also
available. Each AC receptacle is individually controlled/protected with
a circuit breaker. Additionally, the distribution box contains a relay
to control all of the AC outputs; this relay is connected to the
interlock system and requires 3-24 VDC @ 10mA to enable the AC outputs.
The three phases are evenly distributed to nine two-phase outlets to
allow for load balancing.

The schematic diagram of the AC distribution box is shown below:

![](media/image11.wmf){width="7.1in" height="4.7034722222222225in"}

[]{#__RefHeading___Toc36523654 .anchor}Figure 10, Schematic diagram of
AC distribution box.

![](media/image12.jpeg){width="6.666666666666667in" height="5.0in"}

[]{#__RefHeading___Toc36523655 .anchor}Figure 11. Picture of Backplane
Bus Bar Assembly

Figure 12 shows components of the fastener used to attach the backplane
to the bus bar assemblies. The +5V supply is used only for the crate
controller (slot# 1) is attached via a molex style connector.

![](media/image13.wmf)

[]{#__RefHeading___Toc36523656 .anchor}Figure 12. Bus Bar Stud

Figure 13 shows a bottom view of the backplane, fasteners, and section 1
(refer to Figure 6) of the bus bar assembly.

![](media/image14.wmf)

[]{#__RefHeading___Toc36523657 .anchor}Figure 13. Backplane to Bus Bar
Assembly

Figure 14 and Figure 15 show section 1 (refer to Figure 6) of the tin
plated copper bus bar assemblies used for the +3.3V and GND.

![](media/image15.jpeg){width="4.886111111111111in"
height="3.6645833333333333in"}

[]{#__RefHeading___Toc36523658 .anchor}Figure 14. Picture of section 1
of Bus Bar Assembly

![](media/image16.wmf)

[]{#__RefHeading___Toc36523659 .anchor}Figure 15. Mechanical Drawing of
section 1 of Bus Bar Assembly

Figure 16 shows the hardware for sections 1 and 2 (refer to Figure 6) of
the bus bar assemblies used for the +3.3V and GND.

![](media/image17.wmf)

[]{#__RefHeading___Toc36523660 .anchor}Figure 16. Mounting Hardware for
Bus Bar Assembly sections 1 and 2

Figure 17 and Figure 18 show section 2 (refer to Figure 6) of the bus
bar assemblies used for the +3.3V and GND.

![](media/image18.jpeg){width="5.433333333333334in" height="4.075in"}

[]{#__RefHeading___Toc36523661 .anchor}Figure 17. Picture of section 2
of Bus Bar Assembly

![](media/image19.png){width="6.11875in" height="2.417361111111111in"}

[]{#__RefHeading___Toc36523662 .anchor}Figure 18. Mechanical Drawing of
section 2 of Bus Bar Assembly

Figure 19 and Figure 20 show section 3 (refer to Figure 6) of the bus
bar assemblies used for the +3.3V and GND.

![](media/image20.jpeg){width="4.6in" height="3.459722222222222in"}

[]{#__RefHeading___Toc36523663 .anchor}Figure 19. Picture of section 3
of Bus Bar Assembly

![](media/image21.png){width="6.5569444444444445in"
height="3.998611111111111in"}

[]{#__RefHeading___Toc36523664 .anchor}Figure 20. Mechanical Drawing of
section 3 of Bus Bar Assembly

Section 3 of the Bus Bar assembly will be attached to the Vicor power
supply using 8-32 silicon bronze nuts and lock washers.

## Torque Specs

10-32 Silicon Bronze screws : 24 in.-lb \[0.27651 Kg.-m\].

5/16"-18 Phosphor Bronze PEM bolts:

125 in.-lb \[1.440156 Kg.-m\]. (torque spec for silicon bronze)

1/4"-20 Phosphor Bronze PEM bolts:

70 in.-lb. \[0.806487 Kg.-m\](torque spec for silicon bronze)

8-32 Silicon Bronze screws: 21 in.-lb \[0.241946 Kg.-m\].

8-32 Silicon Bronze nuts on Vicor Supply: 10 in.-lb (as per Vicor spec)

# Power source

The +3.3V is supplied by an Vicor Mini PFC power supply \[Ref. 20\]
using three 80 amp modules in parallel for a total of 240 amps @ +3.3V.
+5V will be supplied by a small "brick" style supply.

# Power requirements

As of this writing, estimated power requirements are 240 amps @ +3.3V, 2
amps @ +5V. Gnd is common and requires 240 amps.

# Analysis of Current Densities

The areas of interest are shown below in Figure 21. Each area should
follow the "no more than 1000 amps/sq.in." rule. The charts on the
following pages breakdown each of these areas. For each chart, areas
that conform to the 1000 amps/sq.in. \[155 amps/sq cm\] are colored
green. Areas that don't are colored yellow. Special formulas are listed
where appropriate.

![](media/image22.png){width="5.875in" height="6.5in"}

[]{#__RefHeading___Toc36523669 .anchor}Figure 21. Analysis of Current
Densities; Areas of Interest

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **( | i | ps/sq |                   |
| me |     |      |      | s | sq. | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Po  | P    | Com  | 8 | 0.1 | 1 | 424   | Contact area of   |
| .3 | wer | ower | pres | 0 | 884 |   |       | nut on power      |
| V, | sup | Su   | sion |   | 248 |   | \     | supply (.25       |
| G  | ply | pply | Flat |   |     |   | [65\] | sq.in. \[1.61     |
| ND |     | Bus  |      |   | \[1 |   |       | sq.cm\]) **--**   |
|    |     | Bar  |      |   | .21 |   |       | area consumed by  |
|    |     | sec  |      |   | 564 |   |       | power supply stud |
|    |     | tion |      |   | 1\] |   |       | (.06157522 sq.in. |
|    |     | 3    |      |   |     |   |       | \[.3972587        |
|    |     | for  |      |   |     |   |       | sq.cm\])          |
|    |     | +    |      |   |     |   |       |                   |
|    |     | 3.3v |      |   |     |   |       |                   |
|    |     | and  |      |   |     |   |       |                   |
|    |     | GND. |      |   |     |   |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+

Table 1. Power Supply to Bus Bar section 3

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Sin | Bus  | C    | 8 | 0.  | 1 | 851   | Used cross        |
| .3 | gle | Bar  | ross | 0 | 094 |   |       | sectional area of |
| V, | leg | sec  | Sec  |   |     |   | \[    | Single Leg of Bus |
| G  | of  | tion | tion |   | \[  |   | 131\] | Bar section 3.    |
| ND | s   | 3    |      |   | 0.6 |   |       | Cross section     |
|    | ect |      |      |   | 064 |   |       | area              |
|    | ion |      |      |   | 5\] |   |       | (.188\"x.500\")   |
|    | 3   |      |      |   |     |   |       | \[1.213cm x       |
|    | Bus |      |      |   |     |   |       | 3.226cm\])        |
|    | Bar |      |      |   |     |   |       |                   |
|    | St  |      |      |   |     |   |       |                   |
|    | art |      |      |   |     |   |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523670 .anchor}Table 2. Single Leg of Bus Bar
section 3 Cross Section

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Bus | Bus  | C    | 2 | 0.  | 1 | 571   | Used main area of |
| .3 | Bar | Bar  | ross | 4 | 419 |   |       | bus bar section 3 |
| V, | s   | sec  | Sec  | 0 | 804 |   | \     | (2.549"x.188")    |
| G  | ect | tion | tion |   |     |   | [88\] | \[6.474 cm x      |
| ND | ion | 3    |      |   | \   |   |       | .4775 cm\] **--** |
|    | 3   | fi   |      |   | [2. |   |       | area consumed by  |
|    | st  | nish |      |   | 708 |   |       | stud              |
|    | art |      |      |   | 4\] |   |       | (\".188x.316")    |
|    |     |      |      |   |     |   |       | \[.4775 cm x      |
|    |     |      |      |   |     |   |       | .8026 cm\]        |
+----+-----+------+------+---+-----+---+-------+-------------------+

Table 3. Bus Bar section 3

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | S   | Sur  | Com  | 2 | 0.  | 1 | 324   | Used contact area |
| .3 | urf | face | pres | 4 | 740 |   |       | of Bus Bar        |
| V, | ace | of   | sion | 0 | 425 |   | \     | section 2         |
| G  | of  | Bus  |      |   |     |   | [50\] | (.625"x1.357")    |
| ND | Bus | Bar  |      |   | \   |   |       | \[1.58            |
|    | Bar | sec  |      |   | [4. |   |       | 75cmx3.4468cm\] - |
|    | s   | tion |      |   | 776 |   |       | areas consumed by |
|    | ect | 2    |      |   | 9\] |   |       | 2 mounting holes  |
|    | ion |      |      |   |     |   |       | (.0784 sq.        |
|    | 3   |      |      |   |     |   |       | in.+.0293 sq.     |
|    |     |      |      |   |     |   |       | in.) \[.5058 sq.  |
|    |     |      |      |   |     |   |       | cm + .189 sq.     |
|    |     |      |      |   |     |   |       | cm.\]             |
+----+-----+------+------+---+-----+---+-------+-------------------+

Table 4. Bus Bar section 3 To Bus Bar section 2

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Bus | Bus  | C    | 2 | 0   | 1 | 629   | Cross sectional   |
| .3 | Bar | Bar  | ross | 4 | .38 |   |       | area of bus bar   |
| V, | s   | sec  | Sec  | 0 | 125 |   | \     | section 2         |
| G  | ect | tion | tion |   |     |   | [97\] | (.610"x.625")     |
| ND | ion | 2    |      |   | \[  |   |       | \[1.5494 cm x     |
|    | 2   | c    |      |   | 2.4 |   |       | 1.5875 cm\]       |
|    | cr  | ross |      |   | 596 |   |       |                   |
|    | oss | sec  |      |   | 7\] |   |       |                   |
|    | s   | tion |      |   |     |   |       |                   |
|    | ect | fi   |      |   |     |   |       |                   |
|    | ion | nish |      |   |     |   |       |                   |
|    | st  |      |      |   |     |   |       |                   |
|    | art |      |      |   |     |   |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523671 .anchor}Table 5. Bus Bar section 2 Cross
Section

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | S   | Sur  | Com  | 2 | 0   | 1 | 372   | Area of contact   |
| .3 | urf | face | pres | 4 | .64 |   |       | on Bus Bar        |
| V, | ace | of   | sion | 0 | 505 |   | \     | section 1         |
| G  | of  | Bus  |      |   |     |   | [57\] | (.650"x1.11")     |
| ND | Bus | Bar  |      |   | \   |   |       | \[1.651cm x       |
|    | Bar | sec  |      |   | [4. |   |       | 2.8194cm\] --     |
|    | s   | tion |      |   | 161 |   |       | area of stud hole |
|    | ect | 1    |      |   | 6\] |   |       | (.07645 sq. in.)  |
|    | ion |      |      |   |     |   |       | \[.4932 sq. cm.\] |
|    | 2   |      |      |   |     |   |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523672 .anchor}Table 6. Bus Bar Section 2 to Bus
Bar section 1

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Bus | Bus  | C    | 2 | 0.2 | 1 | 993   | Cross sectional   |
| .3 | Bar | Bar  | ross | 4 | 415 |   |       | area of bus bar   |
| V, | S   | Sec  | Sec  | 0 |     |   | \[    | section 1 (.650\" |
| G  | ect | tion | tion |   | \   |   | 153\] | x .525\")         |
| ND | ion | 1    |      |   | [1. |   |       | \[1.651cm x       |
|    | 1   | End  |      |   | 558 |   |       | 1.334cm\]) --     |
|    | St  |      |      |   | 1\] |   |       | height of busbar  |
|    | art |      |      |   |     |   |       | x width of        |
|    |     |      |      |   |     |   |       | backplane power   |
|    |     |      |      |   |     |   |       | stud\             |
|    |     |      |      |   |     |   |       | (.525\" x .190\") |
|    |     |      |      |   |     |   |       | \[1.334cm x       |
|    |     |      |      |   |     |   |       | .483cm\]).        |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523673 .anchor}Table 7. Bus Bar Section 1 Cross
Section

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Bac | Sp   | Com  | 2 | 0   | 1 | 144.1 | Same spacer as    |
| .3 | kpl | acer | pres | 4 | .16 | 0 |       | +3.3V.            |
| V, | ane | (s   | sion | 0 | 649 |   | \[2   |                   |
| G  | Bus | tand | Flat |   |     |   | 2.3\] | Outside area of   |
| ND | Bar | off) |      |   | \[1 |   |       | spacer            |
|    |     |      |      |   | .07 |   |       |                   |
|    |     |      |      |   | 412 |   |       | (r^2^ where 2r =  |
|    |     |      |      |   | 7\] |   |       | d =.500"          |
|    |     |      |      |   |     |   |       | \[1.27cm\]) --    |
|    |     |      |      |   |     |   |       |                   |
|    |     |      |      |   |     |   |       | Inside area of    |
|    |     |      |      |   |     |   |       | spacer            |
|    |     |      |      |   |     |   |       |                   |
|    |     |      |      |   |     |   |       | (r^2^ where 2r =  |
|    |     |      |      |   |     |   |       | d=.195"           |
|    |     |      |      |   |     |   |       | \[.495cm\])       |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523674 .anchor}Table 8. Bus Bar section 1 to
Spacer (also spacer to Backplane)

+----+-----+------+------+---+-----+---+-------+-------------------+
| ** | **  | **   | **Ty | * | **  | * | **    | **Measurement     |
| Su | Fro | To** | pe** | * | Are | * | Net** | Notes for Area**  |
| pp | m** |      |      | A | a** | \ |       |                   |
| ly |     |      |      | m |     | # | **Am  |                   |
| Na |     |      |      | p | **  | i | ps/sq |                   |
| me |     |      |      | s | (sq | n | in.** |                   |
| ** |     |      |      | * | in. | p |       |                   |
|    |     |      |      | * | )** | a | **\   |                   |
|    |     |      |      |   |     | r | [Amps |                   |
|    |     |      |      |   | *   | a | /sq.c |                   |
|    |     |      |      |   | *\[ | l | m\]** |                   |
|    |     |      |      |   | sq. | l |       |                   |
|    |     |      |      |   | cm\ | e |       |                   |
|    |     |      |      |   | ]** | l |       |                   |
|    |     |      |      |   |     | * |       |                   |
|    |     |      |      |   |     | * |       |                   |
+----+-----+------+------+---+-----+---+-------+-------------------+
| +3 | Bac | Inte | PC   | 2 | 0.  | 1 | 17    | Construction of   |
| .3 | kpl | rnal | b    | 4 | 001 | 0 | 322.9 | thru holes as per |
| V, | ane | p    | oard | 0 | 385 |   |       | Figure 22. The    |
| G  | s   | ower | vias |   |     |   | \[268 | \"cross sectional |
| ND | urf | p    |      |   | \[0 |   | 5.1\] | area of a via\"   |
|    | ace | lane |      |   | .00 |   |       | formula shown     |
|    |     |      |      |   | 893 |   |       | below was used.   |
|    |     |      |      |   | 5\] |   |       | Plating thickness |
|    |     |      |      |   |     |   |       | is .001\"         |
|    |     |      |      |   |     |   |       | \[.0254mm\].      |
|    |     |      |      |   |     |   |       | Finished hole     |
|    |     |      |      |   |     |   |       | size is .190\"    |
|    |     |      |      |   |     |   |       | \[4.83mm\] for    |
|    |     |      |      |   |     |   |       | thru hole, and    |
|    |     |      |      |   |     |   |       | .024\" \[.61mm\]  |
|    |     |      |      |   |     |   |       | for vias. 10      |
|    |     |      |      |   |     |   |       | vias/thru hole    |
+----+-----+------+------+---+-----+---+-------+-------------------+

[]{#__RefHeading___Toc36523675 .anchor}Table 9. Backplane to Power/GND
Plane (thru holes, vias)

Cross Sectional Area of a Via

r~unplated~ -- radius of unplated thru hole (via)

$\text{Area}_{\text{Cross}\ \text{Section}} = \left( \pi \cdot r_{\text{uplated}^{2}} \right) - \left( \pi \cdot r_{\text{plated}^{2}} \right)$r~plated~
-- radius of plated thru hole (via)

Note that all of the current densities in thru holes and vias are beyond
the 1000 amp/sq.in. \[155 amps/sq cm\] limit. The actual issue here is
how much power is lost in these vias, and will the surrounding area be
sufficient to dissipate the heat. Special bus bar mounting screw thru
holes were created in the backplane to increase the number of current
paths. See Figure 22.

![](media/image23.wmf){width="3.5in" height="1.5138888888888888in"}

[]{#__RefHeading___Toc36523676 .anchor}Figure 22. Side View of Through
Hole

Power loss through the vias and thru holes is calculated using the
formula below to determine the resistance of a single via and a single
screw hole. Once these resistances are established, the parallel
resistance of all of the vias and screw holes is determined. The formula

$\text{Power} = \text{Re}\text{sis}\text{tan}\text{ce} \cdot \left( \text{Current} \right)^{2} = R \cdot I^{2}$

is then used to determine how much power would be dissipated in the
area. We used .100" \[2.54mm\] for the variable *x* below. The .100"
\[2.54mm\] is worst case. A temp value of 70C (158F) was used for these
calculations.

*Resistance () of a via or thru hole*[^1]

See Figure 23 for description of variables

Bulk resistivity of copper 6.78710^-7^ (\*in.)

Thermal coefficient of resistance .0039

r~unplated~ -- radius of unplated thru hole or via (in.)

r~plated~ -- radius of plated thru hole or via (in.)

x -- separation between contact points (in.)

temp -- temperature (C)

$\text{Resistance} = \frac{x \cdot \rho}{\left( \pi \cdot r_{\text{unplated}^{2}} \right) - \left( \pi \cdot r_{\text{plated}^{2}} \right)} \cdot \left( 1 + \left( \text{temp} - \text{20} \right) \cdot \text{δρ} \right)$

![](media/image24.wmf){width="3.6354166666666665in"
height="1.9583333333333333in"}

Figure 23. Side View of a Via

Resistance of the .190" \[4.826mm\] dia. thruhole

$R_{\text{190}D} = \frac{\text{.}\text{100} \cdot \rho}{\left( \pi \cdot \text{.}\text{096}^{2} \right) - \left( \pi \cdot \text{.}\text{095}^{2} \right)} \cdot \left( 1 + \left( \text{70} - \text{20} \right) \cdot \text{δρ} \right) = 1\text{.}\text{35152}E - 4\ \Omega$

Resistance of .024\" \[0.610mm\] dia via

$R_{\text{024}D} = \frac{\text{.}\text{100} \cdot \rho}{\left( \pi \cdot \text{.}\text{013}^{2} \right) - \left( \pi \cdot \text{.}\text{012}^{2} \right)} \cdot \left( 1 + \left( \text{70} - \text{20} \right) \cdot \text{δρ} \right) = 9\text{.}\text{38553}E - 5\ \Omega$

R~total~ of +3.3V and GND thru holes and vias

$R_{\text{total}} = \frac{1}{\sum_{}^{}\frac{1}{R_{i}}}$$\text{with}\ 1 \leq i \leq \text{110}$

$\text{for}\ 1 \leq i \leq \text{100}\ \text{is}\ \text{Ri} = R_{\text{024}D} = 9\text{.}\text{38553e-5 }\Omega$

$\text{for}\ \text{101} \leq i \leq \text{110}\ \text{is}\ R_{i} = R_{\text{190}D} = 1\text{.}\text{35152e-4  }\Omega$

$R_{\text{total}} = \frac{1}{\frac{\text{100}}{R_{\text{024}D}} + \frac{\text{10}}{R_{\text{190}D}}} = \frac{1}{\frac{\text{100}}{9\text{.}\text{38553e-5 }} + \frac{\text{10}}{1\text{.}\text{35152e-4 }}} = 8\text{.}\text{77608}E - 7\ \Omega$

Determining power loss in the +3.3V and GND vias and thru holes (Note:
in all formulas used, GND and +3.3V calculations are the same.)

$W_{\text{GND}} = I_{\text{GND}^{2}} \cdot R_{\text{total}} = \left( \text{200}\ \text{Amp} \right)^{2} \cdot 8\text{.}\text{77608}E - 7\ \Omega = 5\text{.}\text{055022}E - 2\ \text{Watt} \simeq \text{50}\text{.}6\ \text{mWatt}$

Following the "power density of a circuit card should be limited to a
maximum of ½ watt per square inch"[^2] rule, the areas of each of the
vias and thru holes are calculated, the total area for thru holes and
vias is found, and the wattage per square inch determined. For these
measurements, the formula for surface area of a cylinder was used. *d*
is the diameter of the thru hole or via, and *x* is the distance from
the backplane outer layer to the plane layer (.100" \[2.54mm\] worst
case).

$A_{\text{thru}_{\text{hole}_{\text{surface}}}} = \pi \cdot d \cdot x$

For the .190" \[4.826mm\] dia. thru hole

$A_{\text{190}\text{surface}} = \pi \cdot \text{.}\text{190} \cdot \text{.}\text{100 }\  = 5\text{.}\text{969E-2  sq}\text{.}\text{in}\text{.} = \text{ 38}\text{.}\text{5096E-2 sq}\text{.}\text{cm}\text{.}$

For the .024" \[0.610mm\] dia. thru hole

$A_{\text{024}\text{surface}} = \pi \cdot \text{.}\text{024} \cdot \text{.}\text{100} = 7\text{.}\text{5398E-3 sq}\text{.}\text{in}\text{.} = \text{ 48}\text{.}\text{644E-3 sq}\text{.}\text{cm}$

As shown before, each thru hole has 10 vias attached to it, and there
are 10 thru holes per power supply. So for each supply,

+3.3V and GND total area

$A_{\text{GNDtotal}} = \text{10} \cdot \left( \text{10} \cdot \left( 7\text{.}\text{5398}E - 3 \right) + 5\text{.}\text{969}E - 2 \right) = 1\text{.}\text{35088}\ \text{sq}\text{.}\text{in } = \text{ 8}\text{.}\text{71534 sq}\text{.}\text{cm}$

Using the power loss figures we calculated earlier, determine the power
loss for unit of area (power density) for the vias and thru holes for
each supply.

$\text{Pd}_{\text{sup}\text{ply} - \text{thruhole}_{\text{loss}}} = \frac{W_{\text{sup}\text{ply}}}{A_{\text{sup}\text{ply}_{\text{thruhole}}}}$

+3.3V and GND thru holes and vias

$\text{Pd}_{\text{GNDthruhole}_{\text{loss}}} = 5\text{.}\frac{\text{055E-2}}{1}\text{.}\text{35088} = 3\text{.}\text{742E-2} = \text{37}\text{.}\text{42}\ \text{mWatt/sq}\text{.}\text{in}\text{.} = \text{ 5}\text{.}\text{8mWatt/sq}\text{.}\text{cm}$

All of these power densities fall well within .500 Watt/sq.in.
\[.0775Watt/sq.cm\] specification.

[]{#__RefHeading___Toc36523677 .anchor}Table 10. Power/GND Plane to
Connector.

  ---------- ---------- ----------- ----------- ---------- ---------- ------------ ------------- -------------------
  **Supply   **From**   **To**      **Type**    **Amps**   **Area (sq **\# in      **Net Amps/Sq **Measurement Notes
  Name**                                                   in.)**     parallel**   in.**         for Area**

  **Supply   **From**   **To**      **Type**    **Amps**   **Area (sq **\# in      **Net Amps/Sq **Measurement Notes
  Name**                                                   in.)**     parallel**   in.**         for Area**

  +3.3V      Thru holes Connector   Power/GND   240        0.045657   2            2628.29358    Total current
             and vias   pins        plane or                                                     divided into cross
                                    copper                                                       sectional area of
                                    pour. Sheet                                                  copper sheet
                                    current                                                      (.0027\" thick),
                                                                                                 over entire width
                                                                                                 of backplane
                                                                                                 (16.91\"). Flow is
                                                                                                 vertical

  GND        Thru holes Connector   Power/GND   240        0.045657   5            1051.317432   Total current
             and vias   pins        plane or                                                     divided into cross
                                    copper                                                       sectional area of
                                    pour. Sheet                                                  copper sheet
                                    current                                                      (.0027\" thick),
                                                                                                 over entire width
                                                                                                 of backplane
                                                                                                 (16.91\"). Flow is
                                                                                                 vertical
  ---------- ---------- ----------- ----------- ---------- ---------- ------------ ------------- -------------------

Like the vias and thru holes listed in the previous chart, the power and
gnd plane layers do not conform to the 1000 amps/sq.in. rule. Instead,
the amount of power dissipated in the power and gnd layers will be
calculated to determine if the backplane can handle the heat loss. The
formula used for power dissipation is W=I^2^R, where R is the resistance
of the plane layers.

The construction of the backplane is such that each bus bar thru hole
feeds the equivalent of two slots (10 thru holes per bus bar for 20
slots). For the resistance calculations below, d~0~ is one bus bar thru
hole and d~i~ is a connector thru hole. Since each slot has multiple
d~i~, we define the equivalent diameter value as:

[]{.mark}$\sqrt{\sum_{}^{}{(d_{i})^{2}}}$

Where *n* is the total number of connector pins in two slots that carry
a particular voltage or gnd. This is defined as a section.

The value used for separation between contact points (x) is always the
worst case instance.

Once the resistance for a section is calculated, the resistance for the
entire plane is calculated by dividing the single section resistance by
the total number of bus bar thru holes, in this case ten. This number is
again divided by the number of times the plane occurs in the backplane
to achieve the total resistance of the planes used for each voltage.

*Calculating resistance () of a power or ground plane with one source
and multiple destinations*[^3]

Bulk resistivity of copper 6.78710^-7^ (in.\* )

Thermal coefficient of resistance .0039

d~0~ -- diameter of 0^th^ contact point (in.)

d~i~ -- diameter of i^nd^ contact point (in.)

t -- thickness of plane (in.)

x -- separation between contact points (in.)

temp -- temperature (C)

$R_{\text{sec}\text{tion}} = \frac{\rho}{2 \cdot \pi \cdot t} \cdot \left\lbrack \text{ln}\left\lbrack \frac{2 \cdot x}{d_{0}} \right\rbrack + \text{ln}\left\lbrack \frac{2 \cdot x}{\sqrt{\sum_{}^{}{(d_{i})^{2}}}} \right\rbrack \right\rbrack \cdot \left( 1 + \left( \text{temp} - \text{20} \right) \cdot \text{δρ} \right)$

Resistance calculations for +3.3V plane(s)

$R_{3\text{.}3V\text{\_sec}\text{tion}} = \frac{6\text{.}\text{787} \cdot \text{10}^{- 7}}{2 \cdot \pi \cdot \text{.}\text{0014}} \cdot \left\lbrack \text{ln}\left\lbrack \frac{2 \cdot 3\text{.}\text{20}}{\text{.}\text{190}} \right\rbrack + \text{ln}\left\lbrack \frac{2 \cdot 3\text{.}\text{20}}{\sqrt{\text{38} \cdot (\text{.}\text{024})^{2}}} \right\rbrack \right\rbrack \cdot \left( 1 + \left( \text{70} - \text{20} \right) \cdot \text{.}\text{0039} \right) = 6\text{.}\text{715}E - 4\Omega$

$R_{3\text{.}3V_{\text{plane}}} = 6\text{.}\text{715}E - 4\frac{\Omega}{\text{10}}\text{sec}\text{tions} = 6\text{.}\text{715}E - 5\Omega$

$R_{3\text{.}3V_{\text{planes}}} = 6\text{.}\text{715}E - 5\frac{\Omega}{2}\text{planes} = 3\text{.}\text{358}E - 5\Omega$

$R_{\text{GND}\text{\_sec}\text{tion}} = \frac{6\text{.}\text{787} \cdot \text{10}^{- 7}}{2 \cdot \pi \cdot \text{.}\text{0014}} \cdot \left\lbrack \text{ln}\left\lbrack \frac{2 \cdot 4\text{.}\text{56}}{\text{.}\text{190}} \right\rbrack + \text{ln}\left\lbrack \frac{2 \cdot 4\text{.}\text{56}}{\sqrt{\text{680} \cdot (\text{.}\text{024})^{2}}} \right\rbrack \right\rbrack \cdot \left( 1 + \left( \text{70} - \text{20} \right) \cdot \text{.}\text{0039} \right) = 6\text{.}\text{040}E - 4\Omega$Resistance
calculations for GND plane(s)

$R_{\text{GND}_{\text{plane}}} = 6\text{.}\text{040}e - 4\frac{\Omega}{\text{10}}\text{sec}\text{tions} = 6\text{.}\text{040}e - 5\Omega$

$R_{\text{GND}_{\text{planes}}} = 6\text{.}\text{040}e - 5\frac{\Omega}{5}\text{planes} = 1\text{.}\text{208}E\text{-5}\Omega$

Power loss in +3.3V plane(s)

$W_{3\text{.}3V_{\text{planes}}} = \text{240}^{2} \cdot 3\text{.}\text{3581}E - 5 = 1\text{.}\text{934}\ \text{Watt}$

Power loss in GND plane(s)

$W_{\text{GND}_{\text{planes}}} = \text{240}^{2} \cdot 1\text{.}\text{028}e - 5 = 6\text{.}\text{958}E - 1\ \text{Watt} \simeq \text{696}\ \text{mWatt}$

Following the "power density of a circuit card should be limited to a
maximum of ½ watt per square inch"[^4] rule, the areas of the planes are
calculated, and the wattage per square inch determined.

$A_{3\text{.}3V_{\text{plane}}} = 3\text{.}\text{40}\text{ cdot }16\text{ }.\text{ }70 = \text{56}\text{.}\text{78}\text{sq}\text{.}\text{in}\text{.}$For
the +3.3V plane

$$\text{Pd}_{3\text{.}3V_{\text{sq}}\text{.}\text{in}\text{.}} = \frac{W_{3\text{.}3V_{\text{planes}}}}{A_{3\text{.}3V_{\text{plane}}}} = (1\text{.}\text{934}\ \text{Watt}\frac{)}{(}\text{56}\text{.}\text{78}\ \text{sq}\text{.}\text{in}\text{.}) = 3\text{.}\text{406}E - 2\ \frac{\text{Watt}}{\text{sq}}\text{.}\text{in}\text{.}$$

$A_{\text{GND}_{\text{plane}}} = 9\text{.}\text{00}\text{ cdot }16\text{ }.\text{ }70 = \text{150}\text{.}3\text{sq}\text{.}\text{in}\text{.}$For
the GND plane

$\text{Pd}_{\text{GND}_{\text{sq}}\text{.}\text{in}\text{.}} = \frac{W_{\text{GND}_{\text{planes}}}}{A_{\text{GND}_{\text{plane}}}} = \frac{6\text{.}\text{958}E - 1\ \text{Watt}}{\text{150}\text{.}\text{30}\ \text{sq}\text{.}\text{in}\text{.}} = 4\text{.}\text{629}E - 3\ \frac{\text{Watt}}{\text{sq}}\text{.}\text{in}\text{.}$

Worse case of the total power density is the watts/sq.in. sum of the 2
plane layers power densities since the 2 layers are stacked on top of
each other.

$\text{Pd}_{\text{total}_{\text{sq}}\text{.}\text{in}\text{.}} = \left( \text{Pd}_{3\text{.}3V_{\text{sq}}\text{.}\text{in}\text{.}} \cdot 2 \right) + \left( \text{Pd}_{\text{GND}_{\text{sq}}\text{.}\text{in}\text{.}} \cdot 5 \right)$

$\text{Pd}_{\text{total}_{\text{sq}}\text{.}\text{in}\text{.}} = \text{68}\text{.}\text{12}E - 3 + \text{23}\text{.}\text{145}E - 3 = \text{91}\text{.}\text{265}E - 3\ \frac{\text{Watt}}{\text{sq}}\text{.}\text{in}$

This value of 91.265 mWatt/sq.in. falls well below the 500 mWatt/sq.in.
(77.5mWatt/sq.cm) guideline.

# Appendix A - Mixer System Backplane connectors pinout

+---+--------+-------+----------+---------+--------+--------+------+
| * | **Row  | **Row | **Row    | **Row   | **Row  | **Row  | *    |
| * | 'z'**  | 'a'** | 'b'**    | 'c'**   | 'd'**  | 'e'**  | *Row |
| P |        |       |          |         |        |        | '    |
| i | **(    |       |          |         |        |        | f'** |
| n | bottom |       |          |         |        |        |      |
| \ | shi    |       |          |         |        |        | **   |
| # | eld)** |       |          |         |        |        | (top |
| * |        |       |          |         |        |        | s    |
| * |        |       |          |         |        |        | hiel |
|   |        |       |          |         |        |        | d)** |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | I     | GND      | INLFT1  | GND    | OUTRT1 |      |
|   |        | NLFT2 |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 2 |        | GND   | INLFT3   | GND     | OUTRT2 | GND    | GND  |
+---+--------+-------+----------+---------+--------+--------+------+
| 3 | GND    | I     | GND      | OUTRT3  | GND    | OUTRT4 |      |
|   |        | NLFT4 |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 4 |        | GND   | INLFT5   | GND     | OUTRT5 | GND    | GND  |
+---+--------+-------+----------+---------+--------+--------+------+
| 5 | GND    | I     | GND      | INLFT6  | GND    | OUTRT6 |      |
|   |        | NLFT7 |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 6 |        | GND   | INLFT8   | GND     | OUTRT7 | GND    | GND  |
+---+--------+-------+----------+---------+--------+--------+------+
| 7 | GND    | I     | GND      | OUTRT8  | GND    | OUTRT9 |      |
|   |        | NLFT9 |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 8 |        | GND   | INLFT10  | GND     | O      | GND    | GND  |
|   |        |       |          |         | UTRT10 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 9 | GND    | IN    | GND      | INLFT11 | GND    | O      |      |
|   |        | LFT12 |          |         |        | UTRT11 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | GND   | INLFT13  | GND     | O      | GND    | GND  |
| 0 |        |       |          |         | UTRT12 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | IN    | GND      | OUTRT13 | GND    | O      |      |
| 1 |        | LFT14 |          |         |        | UTRT14 |      |
+---+--------+-------+----------+---------+--------+--------+------+
|   | pola   |       |          |         |        |        |      |
|   | rizing |       |          |         |        |        |      |
|   | and    |       |          |         |        |        |      |
|   | g      |       |          |         |        |        |      |
|   | uiding |       |          |         |        |        |      |
|   | peg    |       |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
|   |        |       |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
|   |        |       |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | GND   | INLFT15  | GND     | O      | GND    |      |
| 2 |        |       |          |         | UTRT15 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | IN    | GND      | INLFT16 | GND    | O      | GND  |
| 3 |        | LFT17 |          |         |        | UTRT16 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | GND   | INLFT18  | GND     | O      | GND    |      |
| 4 |        |       |          |         | UTRT17 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | IN    | GND      | OUTRT18 | GND    | O      | GND  |
| 5 |        | LFT19 |          |         |        | UTRT19 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | GND   | INLFT20  | GND     | O      | GND    |      |
| 6 |        |       |          |         | UTRT20 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | IN    | GND      | INLFT21 | GND    | O      | GND  |
| 7 |        | LFT22 |          |         |        | UTRT21 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | GND   | INLFT23  | GND     | O      | GND    |      |
| 8 |        |       |          |         | UTRT22 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | IN    | GND      | OUTRT23 | GND    | O      | GND  |
| 9 |        | LFT24 |          |         |        | UTRT24 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 2 | GND    | GND   | INLFT25  | GND     | O      | GND    |      |
| 0 |        |       |          |         | UTRT25 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 2 |        | IN    | GND      | INLFT26 | GND    | O      | GND  |
| 1 |        | LFT27 |          |         |        | UTRT26 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 2 | GND    | GND   | INLFT28  | GND     | O      | GND    |      |
| 2 |        |       |          |         | UTRT27 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | IN    | GND      | OUTRT28 | GND    | O      | GND  |
|   |        | LFT29 |          |         |        | UTRT29 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 2 | GND    | GND   | INLFT30  | GND     | O      | GND    |      |
|   |        |       |          |         | UTRT30 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 3 |        | IN    | GND      | INLFT31 | GND    | O      | GND  |
|   |        | LFT32 |          |         |        | UTRT31 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 4 | GND    | GND   | INLFT33  | GND     | O      | GND    |      |
|   |        |       |          |         | UTRT32 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 5 |        | IN    | GND      | OUTRT33 | GND    | O      | GND  |
|   |        | LFT34 |          |         |        | UTRT34 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 6 | GND    | GND   | INLFT35  | GND     | O      | GND    |      |
|   |        |       |          |         | UTRT35 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 7 |        | IN    | GND      | INLFT36 | GND    | O      | GND  |
|   |        | LFT37 |          |         |        | UTRT36 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 8 | GND    | GND   | INLFT38  | GND     | O      | GND    |      |
|   |        |       |          |         | UTRT37 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 9 |        | IN    | GND      | OUTRT38 | GND    | O      | GND  |
|   |        | LFT39 |          |         |        | UTRT39 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | GND   | INLFT40  | GND     | O      | GND    |      |
| 0 |        |       |          |         | UTRT40 |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | GND   | GND      | INLFT41 | GND    | O      | GND  |
| 1 |        |       |          |         |        | UTRT41 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | MO    | MOD_ID3  | MOD_ID2 | M      | M      |      |
| 2 |        | D_ID4 |          |         | OD_ID1 | OD_ID0 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | +I    | GND      | +O      | +OU    | +OU    | GND  |
| 3 |        | N_CLK |          | UT_CLK0 | T_CLK1 | T_CLK2 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | -I    | GND      | -O      | -OU    | -OU    |      |
| 4 |        | N_CLK |          | UT_CLK0 | T_CLK1 | T_CLK2 |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | GND   | GND      | GND     | GND    | GND    | GND  |
| 5 |        |       |          |         |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | STA   | GND      | S       | GND    | STAT   |      |
| 6 |        | T_CLK |          | TAT_RST |        |        |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | Power | Power    | Power   | Power  | Power  | GND  |
| 7 |        | 3.3V  | 3.3V     | 3.3V    | 3.3V   | 3.3V   |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 | GND    | Power | Power    | Power   | Power  | Power  |      |
| 8 |        | 3.3V  | 3.3V     | 3.3V    | 3.3V   | 3.3V   |      |
+---+--------+-------+----------+---------+--------+--------+------+
| 1 |        | Power | Power    | Power   | Power  | Power  | GND  |
| 9 |        | 3.3V  | 3.3V     | 3.3V    | 3.3V   | 3.3V   |      |
+---+--------+-------+----------+---------+--------+--------+------+

[]{#__RefHeading___Toc36523679 .anchor}Table 11, Pin/Signal assignments
for the backplane top section connector

+---+--------+---------+--------+---------+--------+--------+------+
| * | **Row  | **Row   | **Row  | **Row   | **Row  | **Row  | *    |
| * | 'z'**  | 'a'**   | 'b'**  | 'c'**   | 'd'**  | 'e'**  | *Row |
| P |        |         |        |         |        |        | '    |
| i | **(    |         |        |         |        |        | f'** |
| n | bottom |         |        |         |        |        |      |
| \ | shi    |         |        |         |        |        | **   |
| # | eld)** |         |        |         |        |        | (top |
| * |        |         |        |         |        |        | s    |
| * |        |         |        |         |        |        | hiel |
|   |        |         |        |         |        |        | d)** |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | VADDR7  | VWRITE | VDAT6   | VDAT5  | VDAT2  |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 2 |        | VADDR15 | \*     | VDAT7   | VDAT0  | VDAT3  | GND  |
|   |        |         | SYSRST |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 3 | GND    | VADDR12 | VAS    | VSYSCLK | VDAT1  | VDAT4  |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 4 |        | VADDR9  | \*     | \*VBERR | V      | VADDR5 | GND  |
|   |        |         | VDTACK |         | ADDR13 |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 5 | GND    | VADDR11 | VADDR2 | VADDR10 | VADDR0 | VADDR3 |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 6 |        | VADDR8  | VADDR6 | VADDR1  | V      | VADDR4 | GND  |
|   |        |         |        |         | ADDR14 |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 7 | GND    | Power   | Power  | Power   | Power  | Power  |      |
|   |        | 3.3V    | 3.3V   | 3.3V    | 3.3V   | 3.3V   |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 8 |        | Power   | Power  | Power   | Power  | Power  | GND  |
|   |        | 3.3V    | 3.3V   | 3.3V    | 3.3V   | 3.3V   |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 9 | GND    | OUTLFT2 | GND    | OUTLFT1 | GND    | INRT1  | [    |
|   |        |         |        |         |        |        | ]{.m |
|   |        |         |        |         |        |        | ark} |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | GND     | O      | GND     | INRT2  | GND    | GND  |
| 0 |        |         | UTLFT3 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | OUTLFT4 | GND    | INRT3   | GND    | INRT4  |      |
| 1 |        |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
|   | pola   |         |        |         |        |        |      |
|   | rizing |         |        |         |        |        |      |
|   | and    |         |        |         |        |        |      |
|   | g      |         |        |         |        |        |      |
|   | uiding |         |        |         |        |        |      |
|   | peg    |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
|   |        |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
|   |        |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | O      | GND     | INRT5  | GND    |      |
| 2 |        |         | UTLFT5 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | OUTLFT7 | GND    | OUTLFT6 | GND    | INRT6  | GND  |
| 3 |        |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | O      | GND     | INRT7  | GND    |      |
| 4 |        |         | UTLFT8 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | OUTLFT9 | GND    | INRT8   | GND    | INRT9  | GND  |
| 5 |        |         |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT10 | GND    |      |
| 6 |        |         | TLFT10 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | O       | GND    | INRT11 | GND  |
| 7 |        | UTLFT12 |        | UTLFT11 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT12 | GND    |      |
| 8 |        |         | TLFT13 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | INRT13  | GND    | INRT14 | GND  |
| 9 |        | UTLFT14 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 2 | GND    | GND     | OU     | GND     | INRT15 | GND    |      |
| 0 |        |         | TLFT15 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 2 |        | O       | GND    | O       | GND    | INRT16 | GND  |
| 1 |        | UTLFT17 |        | UTLFT16 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 2 | GND    | GND     | OU     | GND     | INRT17 | GND    |      |
| 2 |        |         | TLFT18 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | INRT18  | GND    | INRT19 | GND  |
|   |        | UTLFT19 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 2 | GND    | GND     | OU     | GND     | INRT20 | GND    |      |
|   |        |         | TLFT20 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 3 |        | O       | GND    | O       | GND    | INRT21 | GND  |
|   |        | UTLFT22 |        | UTLFT21 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 4 | GND    | GND     | OU     | GND     | INRT22 | GND    |      |
|   |        |         | TLFT23 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 5 |        | O       | GND    | INRT23  | GND    | INRT24 | GND  |
|   |        | UTLFT24 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 6 | GND    | GND     | OU     | GND     | INRT25 | GND    |      |
|   |        |         | TLFT25 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 7 |        | O       | GND    | O       | GND    | INRT26 | GND  |
|   |        | UTLFT27 |        | UTLFT26 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 8 | GND    | GND     | OU     | GND     | INRT27 | GND    |      |
|   |        |         | TLFT28 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 9 |        | O       | GND    | INRT28  | GND    | INRT29 | GND  |
|   |        | UTLFT29 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT30 | GND    |      |
| 0 |        |         | TLFT30 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | O       | GND    | INRT31 | GND  |
| 1 |        | UTLFT32 |        | UTLFT31 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT32 | GND    |      |
| 2 |        |         | TLFT33 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | INRT33  | GND    | INRT34 | GND  |
| 3 |        | UTLFT34 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT35 | GND    |      |
| 4 |        |         | TLFT35 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | O       | GND    | INRT36 | GND  |
| 5 |        | UTLFT37 |        | UTLFT36 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT37 | GND    |      |
| 6 |        |         | TLFT38 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | O       | GND    | INRT38  | GND    | INRT39 | GND  |
| 7 |        | UTLFT39 |        |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 | GND    | GND     | OU     | GND     | INRT40 | GND    |      |
| 8 |        |         | TLFT40 |         |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+
| 1 |        | GND     | GND    | O       | GND    | INRT41 | GND  |
| 9 |        |         |        | UTLFT41 |        |        |      |
+---+--------+---------+--------+---------+--------+--------+------+

[]{#__RefHeading___Toc36523680 .anchor}Table 12, Pin/Signal assignments
for the backplane bottom section connector.

# References

> **\[1\]** Howard Johnson, Martin Graham,\
> "High Speed Digital Design", 1993, Prentice Hall PTR. ISBN
> 0-13-395724-1.
>
> **\[2\]** Wade D.Peterson, VMEbus International Trade Association,
> "The VMEbus Handbook", Fourth edition 1997. ISBN 1-885731-08-6.
>
> **\[3\]** "Electrical Design Standards for Electronics to be used in
> Experiment Apparatus at Fermilab", Rev. 4.0 10/16/98
>
> **\[4\]** D0 CTT Mixer System documentation. Information available on
> the Internet:\
> <http://www-ese.fnal.gov/D0_CTT_Mixer/>
>
> **\[5\]** Jamieson T. Olsen,

a.  \"Digital Front End Mother Board register map\", Engineering Note
    2000-01-28a.

b.  \"DFE and Mixer Board Registers \", Engineering Note 2000-01-28a.

c.  \"DFE backplane address/data bus protocol\", Engineering Note
    2000-03-28a.

d.  \"DFE slow monitoring custom serial bus specification\",\
    Engineering Note 2000-01-31a.

e.  Digital Front End Controller (DFEc) Board:\
    <http://d0server1.fnal.gov/users/jamieson/www/projects/dfec/index.html>

> Information available on the internet:
> <http://d0server1.fnal.gov/users/jamieson/www/index.html>
>
> **\[6\]** MIL-STD-1553 is a military standard that defines the
> electrical and protocol characteristics for a data bus. Information on
> the 1553 standard is available on the internet from several sources,
> one of them is:\
> <http://www.1553-mil-std.com/>
>
> **\[7\]** Amp. Web site: <http://www.amp.com/>
>
> **\[8\]** BiRa Systems. Web site: <http://www.bira.com/>
>
> **\[9\]** Cosel USA Inc. Web site: <http://www.coselusa.com/>
>
> **\[10\]** CTS Corporation. Web site: <http://www.ctscorp.com/>
>
> **\[11\]** Harting. Web site: <http://www.harting.com/>
>
> **\[12\]** Littlefuse. Web site: <http://www.littlefuse.com/>
>
> **\[13\]** McMaster-Carr. Web site: <http://www.mcmaster.com/>
>
> **\[14\]** Molex GC/Waldom. Web site: <http://www.molex.com/>
>
> **\[15\]** Panasonic.\
> Web site:
> <http://www.panasonic.com/industrial/components/components.html>
>
> **\[16\]** Raychem. Web site: <http://www.raychem.com/>
>
> **\[17\]** Penn-Engineering. Web site: <http://www.penn-eng.com/>
>
> **\[18\]** Toko. Web site: <http://www.toko.com/>
>
> **\[19\]** Trompeter Electronics. Web site:
> <http://www.trompeter.com/>
>
> **\[20\]** Vicor. Web site: <http://www.vicr.com/>

[^1]: Derived from "High Speed Digital Design, A Handbook of Black
    Magic". Appendix C, pg. 413 *Resistance of a circuit trace*.

[^2]: ^1^ From "Electrical Design Standards for Electronics to be used
    in Experiment Apparatus at Fermilab", Rev. 4.0 10/16/98, pg. 9

[^3]: Derived from "High Speed Digital Design, A Handbook of Black
    Magic". Appendix C, pg. 414 *Resistance of a power or ground plane*

[^4]: ^1^ From "Electrical Design Standards for Electronics to be used
    in Experiment Apparatus at Fermilab", Rev. 4.0 10/16/98, pg. 9