Texas Instruments DS125BR111EVM User manual

DS125BR111EVM User's Guide
SMA Evaluation Kit
User's Guide
Literature Number: SNLU168A
August 2014–Revised August 2014

User's Guide
SNLU168A–August 2014–Revised August 2014
DS125BR111EVM User's Guide
SMA Evaluation Kit
The DS125BR111EVM – SMA evaluation kit provides a complete high bandwidth platform to evaluate the
10GbE, PCIe, and SAS/SATA signal conditioning features of the Texas Instruments DS125BR111
repeater/redriver. The DS125BR111EVM can be used for standard compliance testing, performance
evaluation, and initial system prototyping. The SMA edge launch connectors used for the
DS125BR111EVM will interface to multiple system connector types via commercially available breakout
cables, adaptors, and boards (not included). This flexible connectivity enables integrated system level
testing between TI repeaters and 3rd party ASIC/FPGA host boards.
Topic ........................................................................................................................... Page
1 Features ............................................................................................................. 3
2 Applications........................................................................................................ 3
3 Demo Kit Contents............................................................................................... 3
4 Ordering Information............................................................................................ 3
5 Evaluation Board ................................................................................................. 4
6 Setup.................................................................................................................. 4
7 Expected Results................................................................................................. 7
8 Schematic........................................................................................................... 8
9 Bill of Materials.................................................................................................. 10
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www.ti.com Features
1 Features
• Two Channel Repeater up to 12 Gbps Rate
– DS125BR111: 1x Bidirectional Lane
• Low 65mW/channel Power Consumption, with Option to Power Down Unused Channels
• Advanced Signal Conditioning Features
– Linear Equalization (up to 10 dB @ 6 GHz)
– Linear output drive
– Output voltage range over 1200 mV
• Fully Programmable via Pin Selection or SMBus Interface
• Selectable Single Supply Operation
• 5 kV HBM ESD Rating
• 3.3 V LVCMOS Input Tolerant for SMBus Interface
• Flow–Thru Pinout Package: 24-Pin QFN (4 mm x 4 mm)
• Industrial –40 to 85°C Operating Temperature Range
2 Applications
• High-Speed Cables and Backplanes in Communication Systems
• PCIe, SAS I/II/III, SATA 3/6 Gbps (with OOB detection) and many others
3 Demo Kit Contents
• DS125BR111EVM Board
4 Ordering Information
Table 1. DS125BR111EVM Ordering Information
DEVICE QUANTITY
DS125BR111RTWR 1000
DS125BR111RTWT 250
SMA Evaluation Kit: DS125BR111EVM
3
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Evaluation Board www.ti.com
5 Evaluation Board
Figure 1. DS125BR111EVM Evaluation Board
6 Setup
The DS125BR111EVM – SMA evaluation kit can be used in three different modes:
1. Pin Control (provides access to selected signal integrity settings)
2. SMBus Mode (full access to signal integrity and control settings)
3. EEPROM Mode (full access to signal integrity and control settings)
The EEPROM mode is a convenient method of programming one or more DS125BRxxx devices on
system power-up when a SMBus master (microcontroller or similar) is unavailable in the design. It is
recommended to use a 1 MHz capable EEPROM. The EEPROM must be 8-kbits or smaller.
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HIGH
SIGNAL
RESISTOR
SIGNAL
LOW
4-LEVEL CONTROL
HIGH RESISTOR FLOAT LOW
PIN HEADER CONNECTION
www.ti.com Setup
6.1 DS125BR111 Pin Control
Uses the external control pins on the DS125BR111 to configure the signal integrity and control settings of
the device. Due to the limited number of control pins, a limited bandwidth 4-level input scheme has been
implemented across the control pin interface. This allows for improved EQ and VOD control with fewer
physical pins.
The 4 levels are defined as:
1. Low: 1 KΩto GND
2. Resistor: 20 KΩto GND
3. Float: No External Connection
4. High: 1 KΩto VDD
The EVM interfaces to this 4-level IO using the setup below. Only one shunt connection is required to
access any of the 4 levels. This methodology minimizes the risk of improper connections that could
damage the board or board power supply.
Figure 2. 4-Level IO Control on EVM
The DS125BR111EVM is quickly setup for use in pin control configuration. Jumpers listed below should
be installed on the EVM for pin control.
1. J4 – 3.3 V operation: Use the J1 and J3 connectors to supply 3.3 V power to the EVM. The EVM
power connections are designed to accommodate 1287-ST quick connect tabs or directly soldered to
power leads for connection to a lab power supply.
2. J18 – PWDN = LOW: Device is enabled.
3. J19 – ENSMB = LOW: PIN CONTROL configuration mode.
4. J22 – VDD_SEL = LOW: Uses DS125BR111 internal regulator to convert 3.3 V supply to proper
internal supply level of 2.5 V. Note: The 2.5 V level may be observed on the device VDD pins or the J2
connector.
5. VOD_SEL = 1: Recommended output amplitude settings for CH A and CH B in SAS/SATA and PCIe
applications.
5
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Setup www.ti.com
6.2 SMBus Mode
The SMBus can also be used to control the DS125BR111 devices. This method has the advantage of
independent control and finer signal conditioning granularity.
Table 2. Typical DS125BR111 Register Writes
Register Address Function Description
Register 0x0F CHA EQ Write EQ setting 03’h
Register 0x11 CHA VOD_DB Write VOD_DB setting for bits [2:0] = 000’b
Register 0x23 CHA VOD Write VOD setting for bits [4:2] = 111’b
Register 0x06 CRC DIS Write bit [3] = 1’b send register updates directly to channel without any CRC check.
6.3 EEPROM Mode
A serial EEPROM may also be used to configure one or more DS125BR111 devices. This configuration
mode is accessed by setting the ENSMB 4-level input to FLOAT. For additional information please see the
device datasheet.
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www.ti.com Expected Results
7 Expected Results
This evaluation board has been designed to evaluate the cable and/or FR4 signal conditioning
performance of the DS125BR111. Adding additional cables or adaptor boards into the signal path will
have some impact on the optimal settings, but keeping the adaptor boards small and using short high-
quality SMA cables will minimize this effect.
7.1 Performance
When used in a PCIe or SAS system, it is generally expected that the DS125BR111 will be receiving a
signal with embedded TX FIR information. The DS125BR111 works to extend the reach possible by
adding active linear equalization to the channel, boosting attenuated signals so that they can be more
easily recovered at the SAS-3 Rx. The outputs are specially designed to be transparent to TX FIR
signaling passing this information critical for optimal link training to the SAS-3 Rx. The typical device
settings used in most SAS-3 environments are EQ = Level 4, VOD_DB = 0 and VOD_SEL = 1 in Pin
mode or EQ = 03'h, VOD = 111'b, and VOD_DB = 000'b in SMBus mode.
SETUP1: PRBS7 Generator (no TX FIR) →10" FR4 →DS125BR111EVM →Scope
DS125BR111 Settings
1. VOD_SEL = 1
2. VOD_DB = 0
3. EQ0 = 1
Additional documentation and device performance is available in the device datasheet.
Figure 3. 12 Gbps Eye Diagram at SCOPE in SETUP1
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Schematic www.ti.com
8 Schematic
Figure 4. DS125BR111EVM Schematic
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www.ti.com Schematic
Figure 5. DS125BR111EVM Schematic
9
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Bill of Materials www.ti.com
9 Bill of Materials
Item Quantity Reference Digikey PN Manufacture PN Descriptions
1 1 PCB SV601075 DS125BR111EVM PCB ASSY
C1, C2, C3, C4, C5,
2 10 445-1796-1-ND C0603X5R0J104K CAP CERAMIC .1UF 6.3 V X5R 0201
C6, C7, C8, C9, C11
3 1 C12 1276-1482-1-ND CL05A475MP5NRNC CAP CER 4.7UF 10V 20% X5R 0402
SMA1, SMA2, SMA3,
SMA4, SMA5, SMA6,
4 10 SMA7, SMA8, SMA9, J807-ND 142-0771-821 CONN JACK SMA 50 ΩPC MOUNT
SMA10, SMA11,
SMA12
J4, J5, J6, J7,
J8, J9, J10,
5 14 WM6503-ND 22-28-4033 CONN HEADER 3POS .100 VERT GOLD
J11, J18, J19,
J20, J21, J23, J24
J12, J13, J14,
6 10 J15, J16, J17, WM6502-ND 22-28-4023 CONN HEADER 2POS .100 VERT GOLD
J22, J25, J26, J27
R1, R2, R3, R4,
R5, R6, R13, R14,
R15, R16, R17, R18,
7 27 R21, R22, R23, R24, P1.0KJCT-ND ERJ-2GEJ102X RES 1.0K Ω1/10W 5% 0402 SMD
R26, R27, R28, R30,
R32, R33, R34, R35,
R37, R40, R43
R7,R8,R9,
8 9 R10,R11,R12, P20.0KLCT-ND ERJ-2RKF2002X RES 20.0K Ω1/10W 1% 0402 SMD
R25, R29,R31
9 1 R19 P220JCT-ND ERJ-2GEJ221X RES 220 Ω1/10W 5% 0402 SMD
10 1 R20 P4.7KJCT-ND ERJ-2GEJ472X RES 4.7K Ω1/10W 5% 0402 SMD
11 1 R41, R42 P0.0JCT-ND ERJ-2GE0R00X RES 0.0 Ω1/10W 5% 0402 SMD
12 1 U1 DS125BR111RTW IC REPEATER 2CH 24-QFN (4x4mm)
115-43-308-41-
13 1 U2 ED90197-ND IC SOCKET 8PIN DIP
001000
J30, J31, J32, J33
14 12 J34, J35, J36, J37, 3M9580-ND 969102-0000-DA SHUNT JUMPER .1" BLACK GOLD
J38, J39, J40, J41
15 3 J1, J2, J3 1287-STK-ND 1287-ST Connector TAB 0.250 Solder
16 3 R36, R38, R39 DNP DNP DNP
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