MUX-16 /- 32 /- 64(Data sheet V2.4_01)

16 - fold preamplifier+shaper with timing filterand discriminators,
multiplexed output

mesytec MUX-16 is a very fast 16 channel multiplexed preamplifier shaper anddiscriminator combination with very good energy and timing resolution. Up to two
simultaneously responding channels are identified and two amplitudes plus the twocorresponding amplitude coded addresses are switched to a bus. Up to eight modules(128 channels) can be connected to one bus, so only 4 channels of peak sensing ADCs areneeded to digitize energy and position signals. The modules are especially well suited forsingle hit applications (maximum two hits on one module) with single or double sided
multistrip silicon detectors or multiwire proportional chambers. Due to low power
consumption the MUX-16 PCB can be used in vacuum without cooling.
Features:• High rate:
up to 800 kHz rate capability per bus(1.2 us bus dead time per event)• Very good timing resolution:
1 fast leading edge discriminators perchannel. Ored NIM timing output, reject output• Low noisepreamplifiers and 5th order shaping
amplifier allow very good energy resolution• Very flexible:
sensitivity (and polarity) selectable with rotaryswitch (or RC) in 8 steps• Low power:
1.45 W for 16 channels• Compact: 185 x 100 x 16 mm3• In addition:
fully remote controllable for use in vacuum• Includes 16 channels of bias filter (and ACcoupling) for bias voltages up to ±400 V• Processes single and double hits on one
16 channel unit
• Up to 8 modules = 128 channels on one bus,
only 2 or 4 peak sensing ADC channels needed• Pulser input• Preamplifier input protection• Option: individual discriminator thresholds
for all channels• Reject: signal output if more than 2 hits or if
module collision on the bus

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex output

Schematics:

The figure shows a simplified schematic of theMUX-16 device. Signals from the detector are AC
coupled and pass the charge sensitive
preamplifier. A common bias voltage for all
channels can be applied at the bias input Lemo
connector. It passes a bias filter and feeds each
input via a 10 M resistor. The amplified signals
pass a variable gain circuit which allows to set thegain from 1 to 15 in 8 steps via manual coder or
via remote control. Also the polarity can beadapted to the detector charge polarity.
The signals are now split to the shaping amplifiers
and to the leading edge discriminators withprefilters (20 ns integration time, 100 ns
differentiation time). Their threshold can be set
via potentiometer or via RC and a 12 bit DAC.
The fast signals are then analysed in the hit
decoder, which is able to pick out and calculate
the addresses of up to two hits which occur withina coincidence time of 50 ns. This is done within
30 ns. The decoding is fast enough to be readybefore the slower shaped signals begin to rise, andare used to switch up to two channels to the output
buffer amplifiers. Simultaneously the two 7 bit
output DACs are fed with the 4 address bits aslower bits and the 3 address coder bits as higher
bits. After 80 ns the output drivers are enabled andput their signals to the analog output bus.

From the hit decoder, a NIM signal is emitted tothe trigger / RC bus if no signal is already appliedby another MUX-16 unit on the bus.
To exclude driver collision with another MUX-16
unit, the position and energy bus drivers are onlyenabled when there is no signal on the trigger /RC-bus, and are resetted immediately if there is acollision on the trigger / RC-bus.
This feature can also be used for fast clear, whenan external NIM (current) signal is applied to thetrigger / RC bus. So from arbitration logic of thetrigger bus, a restriction for the MUX-16 system
is: only one module on the same bus may detect
up to two input signals within the coincidence
time (typ 30..100 ns depending on type).
If two different modules get coincident signals,
the event is rejected. If remote control is used, theremote control commands are transmitted fromMRC-1 module via NIM-bus line as positivepulses (+0.6 V) and do not disturb standard NIM
logic. The bus must be terminated on both ends.
Usually an additional driver PCB splits thetrigger/RC bus in a trigger line and an RC busline. The trigger/RC line must be terminated at
one end, and with the other connects to the PCB.
Both PCB outputs, RC and trigger must beterminated.

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex output

Technical Data
Top view

Input side (32 channel case version)

Input stage• Input connector: SubD-25 female connector• Pin assignment:
Function connector Function connector
Sig-gnd 1,2,7,12,13,
Cha 9
1914,15,25
Cha 1
11
Cha 106
Cha 223
Cha 1118
Cha 310
Cha 125
Cha 4
22
Cha 1317
Cha 59Cha 144
Cha 621
Cha 1516
Cha 78Cha 163
Cha 820guardring
24

Output side (32 channel case version)••Positive and negative charge can be amplified
equallyThe guardring output (24) is connected via R-C-Rfilter ( 100 kΩ, 10 nF, 100 kΩ) to the common
detector bias inputs

Noise

50MeV type
• 5.5 keV Si + 0.064 keV /pF(1200 e- FWHM + 18 e- /pF)
• maximum input capacity: 100 pF(detector + cable)
100MeV type6 keV + 0.064 keV /pF
1GeV type<10-3 of selected range
mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex outputPulser inputOutputs

The pulser is distributed to all preamplifier inputs• Tail pulse or square pulse required. The input
is not terminated.
• Sensitivity:
50 MeV type:
15 MeV /V ±10 %100 MeV type:
27 MeV /V
1 Gev type:
55 MeV /V

The output pulses from shaper and position DAC
can be fed to the same peak sensing ADC.

As the multiplexer can only detect up to two
simultaneous signals, for pulser test an automatic
system is implemented: When all channels
respond, two channels are picked out andswitched to the bus. For the next pulser peak theselected channel address is incremented by one.
So with continuous pulser, the selected channel
address cycles around. If many MUX-16 modules
are connected to one bus, the remote control
allows to switch off the outputs of all modules
with exception of one, which is then analysed.

Shaper outputs (Energy output)•Unipolar positive gaussean pulse (CR(RC)5).
Output amplitude: 0 to 3.5 V, max 20 mA

Output signals: Amplitude, NIM-Trigger,
Y=1 V, X= 500 ns
Position outputs

Sensitivity• Sensitivity can be changed by a rotary switch.
The following max ranges (3.5 V output) canbe set:

• Unipolar positive pulse (RC). Output amplitude: 22.2 mV increment per bin, 460 mV
fixed offset, the address coder gives an additional offset of 355 mV x address. Maximum
output range is: 0.46 to 3.3 V, max 20 mA.

50MeV-type
3, 4, 6, 9, 15, 25, 35, 50 MeV
100MeV type6, 8, 12, 20, 30, 50, 70, 100 MeV
1Gev type60, 80, 120, 200, 300, 500, 700, 1000 MeV
Discriminators

Output amplitude / position , Y=1V, X=500ns

Input for the 16 discriminators are fast timing
filter signals, which are amplified together withthe shaper signals. The timing filter stage has anintegration time constant of 22 ns and a differentiation constant of 100 ns. The discriminators havea common threshold, which can be adjusted via 10turn potentiometer or remote control.
The threshold value is available at the senseoutput. 0.8V of output voltage corresponds to
100 % of the chosen sensitivity range.
(80 mV threshold voltage in the 25 MeV range
means 10 % which corresponds to 2.5 MeV
threshold value).

Trigger / RC – Bus

The MUX-16 provides a NIM trigger output
created from ored signal of the timing discriminators. The trigger bus line must be terminated atboth ends with 50 Ω. It is simultaneously used asremote control bus.
Reject output

A NIM signal is emitted when the module is notallowed to send Amplitude and position data(collision at trigger bus or multiplicity >2).

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex output

Detector bias input• Lemo connector• Maximum voltage ±400 V• When detector side must be on ground level
the easiest way is to use a 50 Ω terminator,
which comes very near to a connection toground

Power Supply / output connection
Connector: 20 pole flat wire cable
Function connector Function connector
Sig-gnd2,4,6,8

PowerGnd

9,10,12,17,
18,19,20

Energyoutput 1

1+6 V

13,14,15,16

Position
output 1

5–6 V

11

Energyoutput 2

3

Position
output 2

7

Power consumption• +6 V
280 mA• –6 V–40 mA
Tot power = 1.9 W
Due to the low power consumption the PCB canbe used in vacuum without cooling.
Dimensions• Length:• Width:• Height:

185 mm (with connectors)
100 mm16 mm

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex output

Driver PCB (V 2.1), 10 V type
A driver PCB for in vacuum use is provided
which includes strong output drivers to serve
ADCs with 10 V input range. It also splits the20 pole input flat wire to Lemo 00 series outputs
for the signals which are amplified by a factor 3.3
to interface to 10 (8 V) peak sensing ADCs.

Outputs
Lemo 00 for 10 V ADC from left to right(see picture)
1. Position 2(1.01 V to 7.26 V)

2. Position 1(1.01 V to 7.26 V)

3. Energy 2(0 to 10 V)

4. Energy 1(0 to 10 V)

So for the position output the voltage step between two neighbouring channels is 50 mV.
Other ouputs• Trigger output (must be terminated)• RC IN/Out(set jumper or terminate with 50 Ω if not used)
Power Supply connector

3.2 mm diameter drills
gnd+6 V (max 2.2 A for 8 modules),+12 V–6 V
In addition to the 20 pole flat wire, only theMUX-16 trigger output, the RC bus, the pulser
input and the detector bias input has to beconnected.

Interfacing to MUX-161) 20 pole connector:
Function connector Function connector
Power9,10,12,17,Sig-gnd
2,4,6,8Gnd
18,19,20
Energy13,14,15,
1+6 V
input 1
16
Position
5–6 V
11
input 1
Energy3input 2
Position
7input 2mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shaper
multiplex output

Remote Control

ExampleEach module has a rotary switch to set addresses
0 to 7. The address is used to identify the module,
and to shift the amplitude coded channel
addresses to the right level.

Readout of a 48 channel silicon strip detector.
3 MUX-16 PCBs are needed, they are connected
to one bus. All 3 trigger/RC in/outputs are chained
to one Lemo line and terminated at the end.
The bus is connected to the driver PCB.
Address coders are set to 0, 1, 2.

commands

Deactivate MUX
SE bus dev 0 set-value
Set-value 1 means deactivated, 0 is activated
The "deactivate" feature disables all output drivers. It is important to mask out all devices
except one for pulser test.
Set polarity
SE bus dev 1 set-value
0 is positive and 1 negative charge injection
at the input
Set range// A= 3: Write thresholdSE bus dev 2 set-value
The range is 0 to 7
Set thresholdSE bus dev 3 set-value
The threshold can be set for all channels incommon. The value range is 12 bit: 0...4095.
The maximum value corresponds to about 80 % of
the selected full range.
Set Remote Control on/off
ON bus dev
OFF bus dev

At the rear side, the pulser inputs are chained andterminated at the end. Also all bias inputs arechained to one Lemo cable.
The following connections have to be fed throughthe vacuum vessel (driver PCB inside vacuum):
8 Lemo feedthroughs:• from driver PCBScan bus for connected modules
SC busReturns on/off staus and the Module TypeID (= 23)

1. Energy 1
2. Energy 2
3. Position 1
4. Position 2
5. trigger
6. RC-line• from MUX-16 stack:1. Pulser
2. Detector Bias
3 power feedthroughs + ground (to driver PCB)

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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MUX-16 / - 32 / - 64

16 channel preamplifier / shapermultiplex output

Power consumption

Fast Startup and check:• +6 V• –6 V• +12 VMUX-16, used with driver PCB

610 mA
120 mA
25 mA

Outside vacuum connections

The instrumentation outside the vacuum does notdiffer with the number of MUX-16 devices orchannel number of the detector.
The mesytec MRC-1 module is optional, andhelps to change settings like sensitivities andthresholds for variable setups which do not allow
to break vacuum for adjustments, or if adjustment
can only be done with vacuum conditions.
It also allows pulser test with several MUX-16 devices connected to the bus.

1. Connect power supply to the driver PCB(± 6V, + 12V, gnd).
Check at PCB if all voltages are ok.
2. Connect trigger line (Lemo) between MUX-16
and Driver-PCB. Terminate at the MUX-16
output with T-split and 50 Ω terminator.
3. Connect flat wire between MUX-16 anddriver PCB
4. Connect trigger output of driver PCB to aterminated line (scope with terminated input,NIM-input module...)5. If RC is not used, add jumper to the driver
PCB or terminate RC-input with 50 Ωterminator, else connect RC input to theMRC-1 module.
6. Connect a pulser to MUX-16 pulser input.
With correct polarity and gain setting, signals
will be visible at all amplitude, position andtrigger outputs of the driver PCB.

mesytec GmbH & Co. KG
Wernher-von-Braun-Str. 1, D-85640 Putzbrunn, Germany
phone: +49 - 89 / 456007-30 fax: +49 - 89 / 456007-39
info@mesytec.com - www.mesytec.com

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