SNLS430C October   2012  – August 2014 DS125BR111

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Electrical Characteristics — Serial Management Bus Interface
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
      1. 8.2.1 Functional Datapath Blocks
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pin Control Mode
      2. 8.4.2 SMBus Mode
      3. 8.4.3 Signal Conditioning Settings
    5. 8.5 Programming
    6. 8.6 Register Maps
      1. 8.6.1 Transfer Of Data Via The SMBus
      2. 8.6.2 SMBus Transactions
      3. 8.6.3 Writing a Register
      4. 8.6.4 Reading a Register
      5. 8.6.5 SMBus Register Information
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Signal Integrity
      2. 9.1.2 RX-Detect in SAS/SATA Applications
      3. 9.1.3 PCIe Applications
        1. 9.1.3.1 RXDET When Using SMBus Modes
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

6 Pin Configuration and Functions

24 Pin
Package RTW
Top View
111pinout.gif

The center DAP on the package bottom is the only device GND connection. This pad must be connected to GND through multiple (minimum of 4) vias to ensure optimal electrical and thermal performance.

Pin Functions

PIN I/O DESCRIPTION
NAME NO.
DIFFERENTIAL HIGH SPEED I/O
INB+, INB- 11, 12 I Inverting and non-inverting CML differential inputs to the equalizer. On-chip 50 Ω termination resistor connects INB+ to VDD and INB- to VDD when enabled by RXDET control logic.
AC coupling required on high-speed I/O
OUTB+, OUTB- 20, 19 O Inverting and non-inverting 50 Ω driver outputs. Compatible with AC coupled CML inputs.
AC coupling required on high-speed I/O
INA+, INA- 24, 23 I Inverting and non-inverting CML differential inputs to the equalizer. On-chip 50 Ω termination resistor connects INA+ to VDD and INA- to VDD when enabled by RXDET control logic.
AC coupling required on high-speed I/O
OUTA+, OUTA- 7, 8 O Inverting and non-inverting 50 Ω driver outputs. Compatible with AC coupled CML inputs.
AC coupling required on high-speed I/O
CONTROL PINS — SHARED (LVCMOS)
ENSMB 3 I, 4-LEVEL,
LVCMOS		 System Management Bus (SMBus) enable Pin
Tie 1 kΩ to VDD = Register Access SMBus Slave mode
FLOAT = Read External EEPROM (Master SMBus Mode)
Tie 1 kΩ to GND = Pin Mode
ENSMB = Float or 1 (SMBus MODEs)
SCL 5 I, LVCMOS,
O, OPEN Drain		 ENSMB Master or Slave mode
SMBus clock input Pin is enabled (slave mode).
Clock output when loading EEPROM configuration (master mode).
SDA 4 I, LVCMOS,
O, OPEN Drain		 ENSMB Master or Slave mode
The SMBus bidirectional SDA Pin is enabled. Data input or open drain output. External pull-up required as per SMBus protocol (typically in the 2 kΩ to 5 kΩ range). This pin is 3.3 V-tolerant.
AD0-AD3 10, 9, 2, 1 I, LVCMOS ENSMB Master or Slave mode
SMBus Slave Address Inputs. In SMBus mode, these Pins are the user set SMBus slave address inputs.
READEN 17 I, LVCMOS ENSMB = Float: When using an External EEPROM, a logic low on this pin starts the load from the external EEPROM
ENSMB = 1: When using SMBus Slave Mode the VOD_SEL/READEN pin must be tied Low for the AD[3:0] to be active. If this pin is tied High or Floated an address of 0xB0 will be used for the DS125BR111.
DONE 18 O, LVCMOS When using an External EEPROM (ENSMB = Float), Valid Register Load Status Output
HIGH = External EEPROM load failed or incomplete
LOW = External EEPROM load passed
ENSMB = 0 (PIN MODE)
EQA0
EQB0		 10
1		 I, 4-LEVEL,
LVCMOS 		EQA0 and EQB0 control the level of equalization of the A/B directions. The Pins are defined as EQx0 only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide independent control of each channel. See Table 4.
EQA1
EQB1		 9
2		 I, 4-LEVEL,
LVCMOS 		EQA1 and EQB1 are not used in the DS125BR111 design. These pins should always be tied to GND.
VODA_DB 4 I, 4-LEVEL,
LVCMOS		 VODA_DB controls the CHA output amplitude dynamic range, for SAS and PCIe applications it should be held Low. The Pin is defined as VODA_DB only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide control of each channel, pin 4 is converted to SDA. See Table 5.
VODB_DB 5 I, 4-LEVEL,
LVCMOS		 VODB_DB controls the CHB output amplitude dynamic range, for SAS and PCIe applications it should be held Low. The Pin is defined as VODB_DB only when ENSMB is de-asserted (low). When ENSMB goes high the SMBus registers provide control of each channel, pin 5 is converted to SCL. See Table 5.
SD_TH 14 I, 4-LEVEL,
LVCMOS 		Controls the internal Signal Detect Threshold. This detection threshold is for system debug only and does not control the high speed datapath.
See Table 3.
VOD_SEL 17 I, 4-LEVEL,
LVCMOS		 VOD_SEL controls the low frequency ratio of input voltage to output voltage amplitude. See Table 5.
RXDET 18 I, 4-LEVEL,
LVCMOS 		The RXDET Pin controls the receiver detect function. Depending on the input level, a 50 Ω or > 50 kΩ termination to the power rail is enabled. In a SAS/SATA system RXDET should be set to a Logic "1" state to keep the termination always enabled.
The RXDET pin only controls the RXDET function in PIN MODE. PCIe applications which require SMBus Mode functionality must utilize a specific register write sequence documented in PCIe Applications . If this sequence is not utilized, SMBus configuration modes will default the input terminations to active (50 Ω). See Table 2 .
CONTROL PINS — BOTH PIN AND SMBus MODES (LVCMOS)
RES 13 I, 4-LEVEL,
LVCMOS 		Reserved:
This input must be left Floating.
VDD_SEL 16 I, FLOAT Controls the internal regulator
Float = 2.5 V mode
Tie GND = 3.3 V mode
PWDN 6 I, LVCMOS Tie High = Low power - power down
Tie GND = Normal Operation
See Table 2.
POWER (See Figure 11)
VIN 15 Power In 3.3 V mode, feed 3.3 V to VIN
In 2.5 V mode, leave floating.
VDD 21, 22 Power Power supply pins CML/analog
2.5 V mode, connect to 2.5 V
3.3 V mode, decouple each VDD pin with 0.22 µF cap to GND
GND DAP Power Ground pad (DAP - die attach pad).