SATA Standard spec. for internal
connection with FPC cable White Paper

2011-01-31
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Background
For application using HDD, there are cases of selecting FPC cable forflexible and longer connection between HDD and Motherboard etc…
Especially for the application such as Car navigation systems, there aremany cases to select FPC because of its flexibility as thin and varied
length options. Currently, the use case limitation/market condition isvaried and up to the specification of each application/each company.
This proposal is to show the result of FPC cable length to meet SATA
standard and rough guide for spec. under realistic use case condition.
For the test, we chose Yamaichi made FPC cable (YFLEXTM) andconnector for all test and simulation.

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MOI test with YFLEXTM L=300mm
YFLEXTM L=300mm was tested under condition of “Serial ATA Interoperability Program
Tektronix MOI for SI Cable Tests Version .8”( Test condition and result is followed in this material)
As the test result, there is 2 items which could not be compliant with the current standard.
However, there is no problem in performance to use in an application.
Also, Host manufacturers need cable length as same as legacy solution and they need
Judge-criteria for FPC.

Considering use-case of necessary cable length, there are following 2 options.
However, it would be more realistic to define new criteria with considering real use-case.
1) To loosen standard for 2 items which could not be compliant the current
standard,Or2) To define FPC length which could be compliant all standard items.
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FPC Detail
YFLEXTM structure
YFLEXTM Structure: cross section※ FPC Pad area is key factor for its
performance. Since there are some effectfrom contact pitch etc…, it is preferred to
specialize design with matching connector.

Test sample
L=300mm(200mm)

YFLEX cable and connector(Yamaichi products, YFLEXTM andHF601-22-03)
4/31

Connector & Test Board DetailYamaichi FPC connector

Test Board

PCB：Yamaichi Original
SMA：SOUTH WEST

Connector：Yamaichi HF601

FPC connector outline

Data line length L=29.8mm

Test Board performance

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Test items and test equipment
It was measured by referring to “Serial ATA Interoperability Program Tektronix MOI for
SI Cable Tests Version. 8” with using DSA8200, I-connect.
* SI-07 cross talk was measured by Agilent N5230A.
Serial ATA Interoperability Program Tektronix MOI for SI Cable Tests
Referred spec.

Equipment

SI-01

Tektronix MOI p8

DSA8200、、I-connect

SI-02

Tektronix MOI p10

DSA8200、、I-connect

SI-03

Tektronix MOI p12

DSA8200、、I-connect

SI-04

Tektronix MOI p13

DSA8200、、I-connect

SI-05

Tektronix MOI p14

DSA8200

SI-06

Tektronix MOI p15

DSA8200

SI-07

Tektronix MOI p16

DSA8200、、I-connect

SI-08

Tektronix MOI p18

N5230A (Agilent)

SI-09

Tektronix MOI p21

DSA8200、、I-connect

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Test overview
Measurement

Measurement condition
SI-01,SI-02,SI-03,SI-04,SI-05,SI-06,SI-07,SI-09 weremeasured by the connection on the left photo.
TDT measurement was operated as the left photo.
TDR measurement was operated with setting one side of
YFLEXTM as OPEN.

Connection overview
DSA 8200
80E04

80E10

Equipment
DSA8200 (Tektronix)

Test Board

Test Board
SMA

SMA
Coax cable

HF601
-03

SMA

YFLEXTM

HF601

Coax cable

-03
SMA

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Test overview
Measurement

Measurement condition
SI-08, etc… were measured by the connection onthe left photo.
Cross talk measurement was set coax cable toconnect adjacent differential pair and terminated oneside.

Connection overview

N5230A

Test Board

Equipment
N5230A (Agilent)

Test Board

SMA

Coax cable

SMA
HF601
-03

SMA

HF601

Coax cable

YFLEXTM -03

SMA

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Test result

SpecSpec. value

Result300mm (200mm)

SI-01

Mated Connector Impedance

100Ω±15%85.5Ω~103Ω
(85.5Ω~103Ω)

SI-02

Cable Absolute Impedance

100Ω±10%98Ω~100Ω
(95~102Ω)SI-03

Cable Pair Matching±5Ω~0.3Ω (~2.9Ω)SI-04

Common Mode Impedance

25-40Ω

Max:32.5Ω
(Max:32.2Ω)SI-05

Differential Rise Time

85ps

124.6ps (73.3ps)

SI-06

Intra-Pair Skew

10ps

1.0ps (0.1ps)

SI-07

Insertion Loss

6dB@
10-4500MHz-7.1dB@4500MHz(-4.7dB@4500MHz)

SI-08

Differential to Differential
Crosstalk:NEXT

26dB@
10-4500MHz-41dB @ 4500Mhz(-41dB @ 4500MHz)

SI-09

Inter-Symbol Interference

50ps

20.3ps (13.0ps)
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Test result
2.7.1. SI-01 : Mated Connector Impedance<SPEC>

Mated Connector Differential Impedance 100Ohms ±15%

<Result>

MAX:103Ω MIN:85.7Ω

Connector + Board
Range of evaluation
115Ω
Ω

100Ω
Ω85ΩΩ
500ps

10/31

Test result
2.7.2. SI-02 : Cable Absolute Impedance<SPEC>

Cable Absolute Differential Impedance 100Ohms±10%<Result>

MAX:100Ω MIN:98Ω

Range of evaluation

110Ω
Ω

100Ω
Ω

90Ω
Ω

500ps

11/31

Test result
2.7.3. SI-03 : Cable Pair Matching<SPEC>

Cable Pair Matching Impedance ±5Ohm<Result>

Min-Min:0.1Ω

Max-Max:0.3Ω

Range of evaluation
55Ω
Ω
50Ω
Ω
45Ω
Ω

500ps

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Test result
2.7.4. SI-04 : Common Mode Impedance<SPEC>

Common Mode Impedance 25-40Ohms<Result>

Max:32.5Ω

40Ω
Ω
評価範囲

Range of evaluation
Connector

25Ω
Ω

500ps

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Test result
2.7.5. SI-05 : Differential Rise Time
<SPEC>

Maximum Rise Time 85ps(20%-80%)<Result>

124.6ps
Diff. Rise Time

80%

20%

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Test result
2.7.6. SI-06 : Intra-Pair Skew
<SPEC>

Maximum Intra-Pair Skew 10ps

<Result>

1.0ps

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Test result
2.7.7. SI-07 : Insertion Loss
<SPEC>

Maximum insertion Loss (10-4500MHz)6dB<Result>-7.1dB@4500MHz
4.5GHzRange of evaluation-6dB(SPEC)-7.1dB

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Test result
2.7.8. SI-08 : Differential to Differential Crosstalk:NEXT<SPEC>

Maximum Crosstalk:NEXT (10-4500MHz)26dB<Result>-41dB @ 4500Mhz
4500MHz

Range of evaluation

SPEC：-26dB

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Test result
2.7.9. SI-09 : Inter-Symbol Interference<SPEC>

Maximum Inter-Symbol Interference 50ps

<Result>

20.3ps

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How to take SATA standard for FPC cable internal connection
There is no significant problem under real use case in an applicationeven though YFLEXTM L=300mm could not compliant with cable spec.
“ Serial ATA Interoperability Program Tektronix MOI for SI Cable Tests
Version .8
However, it should be defined limitation of usage as criteria.
Therefore, Yamaichi operated simulation and test with proto-typesample for defining criteria of use-limitation based on test result inprevious slides.
* Cable length was considered as actual length to use and its tolerance
range.

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YFLEXTM design by simulation and evaluation
YFLEXTM design overview (Single end : 50ohm / Differential : 100ohm)
L=100mm,200mm,300mm,

SMA connector: SOUTH WEST products

400mm,500mm
X

X’

Structure, X-X’cross section
SIG

SIG
Cover: 50um

Cu:18um

Base : 50um
Cu:18um
Pitch 0.5mm(Referred to FPC connector)
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Insertion Loss per Length difference
Test result
【dB】

-6dB

--- YFLEX 100mm---YFLEX 400mm--- YFLEX 200mm---YFLEX 500mm--- YFLEX 300mm

L=280mm is the length to meet Serial
ATA Interoperability Program spec. as
YFLEXTM itself.
4.5GHz21/31

Insertion Loss difference between measured data and simulation data
Test result【dB】
Verified Simulation preciseness to calculate tolerance
range.
⇒ Simulation and tested sample are mostly equal.

--- Measurement YFLEX 200mm--- Measurement YFLEX 200mm+HF601connector--- Simulation YFLEX 200mm

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Insertion Loss with considering tolerance variation
Simulation result

【dB】

-6dB

Solid line: Nominal
Dot line: Worst Tolerance
4.5GHz--- YFLEX100mm---YFLEX400mm--- YFLEX200mm---YFLEX500mm--- YFLEX300mm

Tolerance was considered Basement
thickness and preciseness of etching.

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YFLEXTM length to meet Insertion Loss spec.
Simulation result

【dB】

-6.0

L=240mm approx. is the length to meetspec. as YFLEXTM itself.

--- Simulation YFLEX 240mm
Worst Tolerance

4.5GHz24/31

Insertion Loss Measurement (YFLEXTM itself)
Test result
100mm

200mm

300mm

S21 ref

S21 ref

S21 ref

S11/S22 ref

S11/S22 ref

S11/S22 ref

400mm

500mm

S21 ref

S21 ref

S11/S22 ref

S11/S22 ref25/31

Differential Rise Time (YFLEXTM itself)
Test result【ps】

250200150100

SPEC:85ps
50220mm
0050

100

150

200

250

300

350

400450YFLEX Length [mm]26/31Differential Rise Time Measurement (YFLEXTM itself)
Test result
200mm

300mm

400mm

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Insertion Loss Measurement (YFLEXTM + Connector)
Test result【dB】

YFLEX200mm+HF601--- YFLEX200mm

YFLEX300mm+HF601
YFLEX400mm+HF601
YFLEX500mm+HF601

4.5GHz28/31

Differential Rise Time Measurement (YFLEXTM + Connector)
Test result【ps】

YFLEX+CN

YFLEX

SPEC

YFLEX length (mm)29/31

Result• In case to prioritize compliance with Serial ATA Interoperability Program standard, Length
should be around 240mm from Insertion Loss criteria.
• In case to prioritize to prioritize the length for internal connection, Length should be necessary
300mm max and Insertion Loss criteria should loosen around –7.5dB.
• In case to prioritize compliance with Serial ATA Interoperability Program standard, Length
should be around 230mm from Differential Rise Time criteria.

• For Differential Rise Time test, FPC connector effect could not be ignored. FPC connector
should be designed for high speed data transmission capability.

• All the test/simulation was operated with estimated cable length and it would be necessary formore detailed analysis for longer cable requirement. Also, connector for FPC cable, it ispreferred to select a connector with high speed data transmission capability,30/31

Proposal
Yamaichi propose to add [ FPC + connectors] as one of data transmission methods on S-ATA spec tomeet market inquiry.
Host internal connection should be 300mm maximum.
With measured data as we introduced in this material, Yamaichi propose following 2 options on“Insertion Loss” and setting “Differential Rise Time” as exception. The reason “Insertion Loss”
and “Differential Rise Time” are selected for spec compliance is because these 2 are thetoughest among several compliance check items in S-ATA Interoperability Program standard.

Insertion Loss Option: either 1 or 2, proposal
1. To compliant current Insertion Loss spec as –6dB@4.5GHz,
defining whole data transmission length as 250mm
or2.

Loosen Insertion Loss spec to around -7.5dB@4.5GHz,
to meet Host internal connection(market request) of 300mm maximum
as for whole data transmission length
Differential Rise Time, proposal
To set this item as EXCEPTION for [ FPC + FPC connector] S-ATA datatransmission, because SI characteristics shall be able to check by Insertion
Loss and other compliance check items in S-ATA Interoperability Program.
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