SNLS398H January   2012  – February 2018 DS125DF410

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Typical Application Diagram
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Data Path Operation
      2. 7.3.2 Signal Detect
      3. 7.3.3 CTLE
      4. 7.3.4 DFE
      5. 7.3.5 Clock and Data Recovery
      6. 7.3.6 Output Driver
      7. 7.3.7 Device Configuration
        1. 7.3.7.1 Rate and Subrate Setting
    4. 7.4 Device Functional Modes
      1. 7.4.1 SMBus Master Mode and SMBus Slave Mode
      2. 7.4.2 Address Lines <ADDR_[3:0]>
      3. 7.4.3 SDA and SDC
      4. 7.4.4 Standards-Based Modes
        1. 7.4.4.1 Ref_mode 3 Mode (Reference Clock Required)
        2. 7.4.4.2 False Lock Detector Setting
        3. 7.4.4.3 Reference Clock In
        4. 7.4.4.4 Reference Clock Out
        5. 7.4.4.5 Driver Output Voltage
        6. 7.4.4.6 Driver Output De-Emphasis
        7. 7.4.4.7 Driver Output Rise/Fall Time
        8. 7.4.4.8 INT
        9. 7.4.4.9 LOCK_3, LOCK_2, LOCK_1, and LOCK_0
    5. 7.5 Programming
      1. 7.5.1  SMBus Strap Observation
      2. 7.5.2  Device Revision and Device ID
      3. 7.5.3  Control/Shared Register Reset
      4. 7.5.4  Interrupt Channel Flag Bits
      5. 7.5.5  SMBus Master Mode Control Bits
      6. 7.5.6  Resetting Individual Channels of the Retimer
      7. 7.5.7  Interrupt Status
      8. 7.5.8  Overriding the CTLE Boost Setting
      9. 7.5.9  Overriding the VCO Search Values
      10. 7.5.10 Overriding the Output Multiplexer
      11. 7.5.11 Overriding the VCO Divider Selection
      12. 7.5.12 Using the PRBS Generator
      13. 7.5.13 Using the Internal Eye Opening Monitor
      14. 7.5.14 Overriding the DFE Tap Weights and Polarities
      15. 7.5.15 Enabling Slow Rise/Fall Time on the Output Driver
      16. 7.5.16 Inverting the Output Polarity
      17. 7.5.17 Overriding the Figure of Merit for Adaptation
      18. 7.5.18 Setting the Rate and Subrate for Lock Acquisition
      19. 7.5.19 Setting the Adaptation/Lock Mode
      20. 7.5.20 Initiating Adaptation
      21. 7.5.21 Setting the Reference Enable Mode
      22. 7.5.22 Overriding the CTLE Settings Used for CTLE Adaptation
      23. 7.5.23 Setting the Output Differential Voltage
      24. 7.5.24 Setting the Output De-Emphasis Setting
    6. 7.6 Register Maps
      1. 7.6.1 Register Information
      2. 7.6.2 Bit Fields in the Register Set
      3. 7.6.3 Writing to and Reading from the Control/Shared Registers
      4. 7.6.4 Channel Select Register
      5. 7.6.5 Reading to and Writing from the Channel Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5 Pin Configuration and Functions

48-Pin WQFN
Package RHS
Top View
DS125DF410 30161026.gif

Pin Functions

PINTYPE
I/O (1)		DESCRIPTION
NAMENO.
HIGH-SPEED DIFFERENTIAL I/O
RXP0
RXN0		 1
2		 I, CML Inverting and non-inverting CML-compatible differential inputs to the equalizer. Nominal differential input impedance = 100Ω.
RXP1
RXN1		 4
5		 I, CML Inverting and non-inverting CML-compatible differential inputs to the equalizer. Nominal differential input impedance = 100Ω.
RXP2
RXN2		 8
9		 I, CML Inverting and non-inverting CML-compatible differential inputs to the equalizer. Nominal differential input impedance = 100Ω.
RXP3
RXN3		 11
12		 I, CML Inverting and non-inverting CML-compatible differential inputs to the equalizer. Nominal differential input impedance = 100Ω.
TXP0
TXN0		 36
35		 O, CML Inverting and non-inverting CML-compatible differential outputs from the driver. Nominal differential output impedance = 100Ω.
TXP1
TXN1		 33
32		 O, CML Inverting and non-inverting CML-compatible differential outputs from the driver. Nominal differential output impedance = 100Ω.
TXP2
TXN2		 29
28		 O, CML Inverting and non-inverting CML-compatible differential outputs from the driver. Nominal differential output impedance = 100Ω.
TXP3
TXN3		 26
25		 O, CML Inverting and non-inverting CML-compatible differential outputs from the driver. Nominal differential output impedance = 100Ω.
LOOP FILTER CONNECTION PINS
LPF_CP_0
LPF_REF_0		 47
48		 I/O, analog Loop filter connection
Place a 22 nF ± 10% Capacitor between LPF_CP_0 and LPF_REF_0
LPF_CP_1
LPF_REF_1		 38
37		 I/O, analog Loop filter connection
Place a 22 nF ± 10% Capacitor between LPF_CP_1 and LPF_REF_1
LPF_CP_2
LPF_REF_2		 23
24		 I/O, analog Loop filter connection
Place a 22 nF ± 10% Capacitor between LPF_CP_2 and LPF_REF_2
LPF_CP_3
LPF_REF_3		 14
13		 I/O, analog Loop filter connection
Place a 22 nF ± 10% Capacitor between LPF_CP_3 and LPF_REF_3
REFERENCE CLOCK I/O
REFCLK_IN 19 I, 2.5 V analog Input is 2.5 V, 25 MHz ± 100 ppm reference clock from external oscillator
No stringent phase noise requirement
REFCLK_OUT 42 O, 2.5 V analog Output is 2.5 V, buffered replica of reference clock input for connecting multiple DS125DF410s on a board
LOCK INDICATOR PINS
LOCK0
LOCK1
LOCK2
LOCK3		 45
40
21
16		 O, 2.5 V LVCMOS Output is 2.5 V, the pin is high when CDR lock is attained on the corresponding channel.
Note that these pins are shared with SMBus address strap input functions read at startup.
SMBus MASTER MODE PINS
ALL_DONE 41 O, 2.5 V LVCMOS Output is 2.5 V, the pin goes low to indicate that the SMBus master EEPROM read has been completed.
READ_EN 44 I, 2.5 V LVCMOS Input is 2.5 V, a transition from high to low starts the load from the external EEPROM. The READ_EN pin must be tied low when in SMBus slave mode.
INTERRUPT OUTPUT
INT 43 O, 3.3 V LVCMOS,
Open Drain		 Used to signal horizontal or vertical eye opening out of tolerance, loss of signal detect, or CDR unlock.
External 2kΩ to 5kΩ pull-up resistor is required.
Pin is 3.3 V LVCMOS tolerant.
SERIAL MANAGEMENT BUS (SMBus) INTERFACE
EN_SMB 20 I, 2.5 V analog Input is 2.5 V, selects SMBus master mode or SMBus slave mode.
EN_SMB = High for slave mode
EN_SMB = Float for master mode
Tie READ_EN pin low for SMBus slave mode. See Table 4
SDA 18 I/O, 3.3 V LVCMOS,
Open Drain		 Data Input / Open Drain Output
External 2kΩ to 5kΩ pull-up resistor is required.
Pin is 3.3 V LVCMOS tolerant.
SDC 17 I/O, 3.3 V LVCMOS,
Open Drain		 Clock Input / Open Drain Clock Output
External 2kΩ to 5kΩ pull-up resistor is required.
Pin is 3.3 V LVCMOS tolerant.
ADDR_0
ADDR_1
ADDR_2
ADDR_3		 45
40
21
16		 I, 2.5 V LVCMOS Input is 2.5 V, the ADDR_[3:0] pins set the SMBus address for the retimer.
These pins are strap inputs. Their state is read on power-up to set the SMBus address in SMBus control mode.
High = 1kΩ to VDD, Low = 1kΩ to GND
Note that these pins are shared with the lock indicator functions. See Table 1
POWER
VDD 3, 6, 7,
10, 15, 46		 Power VDD = 2.5 V ± 5%
GND 22, 27,
30, 31,
34, 39		 Power Ground reference.
DAP PAD Power Ground reference. The exposed pad at the center of the package must be connected to ground plane of the board with at least 4 vias to lower the ground impedance and improve the thermal performance of the package.
(1) I = Input, O = Output and 2.5V LVCMOS pins are 2.5 V levels only.
Only SMBus pins SDA and SDC and INT pin are 3.3 V tolerant. These three pins are open-drain and require external pull-up resistors.