SLLS373M July   1999  – March 2024 SN65LVDS1 , SN65LVDS2 , SN65LVDT2

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Options
  6. 5 Pin Configuration and Functions
  7. 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 Driver Electrical Characteristics
    6. 6.6 Receiver Electrical Characteristics
    7. 6.7 Driver Switching Characteristics
    8. 6.8 Receiver Switching Characteristics
    9. 6.9 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 SN65LVDS1 Features
        1. 8.3.1.1 Driver Output Voltage and Power-On Reset
        2. 8.3.1.2 Driver Offset
        3. 8.3.1.3 5-V Input Tolerance
        4. 8.3.1.4 NC Pins
        5. 8.3.1.5 Driver Equivalent Schematics
      2. 8.3.2 SN65LVDS2 and SN65LVDT2 Features
        1. 8.3.2.1 Receiver Open Circuit Fail-Safe
        2. 8.3.2.2 Receiver Output Voltage and Power-On Reset
        3. 8.3.2.3 Common-Mode Range vs Supply Voltage
        4. 8.3.2.4 General Purpose Comparator
        5. 8.3.2.5 Receiver Equivalent Schematics
        6. 8.3.2.6 NC Pins
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation With VCC < 1.5 V
      2. 8.4.2 Operation With 1.5 V ≤ VCC < 2.4 V
      3. 8.4.3 Operation With 2.4 V ≤ VCC < 3.6 V
      4. 8.4.4 SN65LVDS1 Truth Table
      5. 8.4.5 SN65LVDS2 and SN65LVDT2 Truth Table
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Point-to-Point Communications
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Driver Supply Voltage
          2. 9.2.1.2.2  Driver Bypass Capacitance
          3. 9.2.1.2.3  Driver Input Voltage
          4. 9.2.1.2.4  Driver Output Voltage
          5. 9.2.1.2.5  Interconnecting Media
          6. 9.2.1.2.6  PCB Transmission Lines
          7. 9.2.1.2.7  Termination Resistor
          8. 9.2.1.2.8  Driver NC Pins
          9. 9.2.1.2.9  Receiver Supply Voltage
          10. 9.2.1.2.10 Receiver Bypass Capacitance
          11. 9.2.1.2.11 Receiver Input Common-Mode Range
          12. 9.2.1.2.12 Receiver Input Signal
          13. 9.2.1.2.13 Receiver Output Signal
          14. 9.2.1.2.14 Receiver NC Pins
      2. 9.2.2 Application Curve
      3. 9.2.3 Multidrop Communications
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
          1. 9.2.3.2.1 Interconnecting Media
        3. 9.2.3.3 Application Curve
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Microstrip vs. Stripline Topologies
      2. 11.1.2 Dielectric Type and Board Construction
      3. 11.1.3 Recommended Stack Layout
      4. 11.1.4 Separation Between Traces
      5. 11.1.5 Crosstalk and Ground Bounce Minimization
      6. 11.1.6 Decoupling
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Other LVDS Products
    2. 12.2 Third-Party Products Disclaimer
    3. 12.3 Documentation Support
      1. 12.3.1 Related Information
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Support Resources
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • DBV|5
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.2.1 Receiver Open Circuit Fail-Safe

One of the most common problems with differential signaling applications is how the system responds when no differential voltage is present on the signal pair. The LVDS receiver is like most differential line receivers in that its output logic state can be indeterminate when the differential input voltage is between –100 mV and 100 mV and within its recommended input common-mode voltage range. However, the TI LVDS receiver is different in how it handles the open-input circuit situation.

Open circuit means that there is little or no input current to the receiver from the data line itself. This could be when the driver is in a high-impedance state or the cable is disconnected. When this occurs, the LVDS receiver pulls each line of the signal to VCC through 300-kΩ resistors as shown in Figure 8-2. The fail-safe feature uses an AND gate with input voltage thresholds at about 2.3 V to detect this condition and force the output to a high level.

SN65LVDS1 SN65LVDS2 SN65LVDT2 Open-Circuit Fail-Safe of the LVDS ReceiverFigure 8-2 Open-Circuit Fail-Safe of the LVDS Receiver

It is only under these conditions that the output of the receiver is valid with less than a 100-mV differential input voltage magnitude. The presence of the termination resistor, Rt does not affect the fail-safe function as long as it is connected as shown in Figure 8-2. Other termination circuits may allow a dc-current to ground that could defeat the pullup currents from the receiver and the fail-safe feature.