SNOAA35E December   2023  – June 2024 LM2901 , LM2901B , LM2901B-Q1 , LM2903 , LM2903-Q1 , LM2903B , LM2903B-Q1 , LM339 , LM339-N , LM393 , LM393-N , LM393B , LM397 , TL331 , TL331-Q1 , TL331B

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Devices Covered in Application Note
    1. 1.1 Base Part Numbers
    2. 1.2 Input Voltage Offset Grades
    3. 1.3 Maximum Supply Voltage
    4. 1.4 High Reliability Options
  5. 2 The New TL331B, TL391B, LM339B, LM393B, LM2901B and LM2903B B Versions
  6. 3 PCN's to Change Classic Die to a New Die Design
    1. 3.1 PCN #1 for Single and Dual (TL331 and LMx93/LM2903)
    2. 3.2 PCN #2 for Single and Dual (TL331 and LMx93/LM2903)
    3. 3.3 PCN For Quad (LMx39/LM2901)
    4. 3.4 Device PCN Summary
    5. 3.5 Determining Die Version Used
      1. 3.5.1 Determine Die Used for Single TL331 and Dual LM293, LM393, and LM2903 - PCN #1 (Ji3)
      2. 3.5.2 Determine Die Used for Single TL331 and Dual LM293, LM393, and LM2903 - PCN #2 (TiB)
      3. 3.5.3 Determine Die Used for Quad LM139, LM239, LM339, and LM2901
  7. 4 Changes to Package Top Markings
  8. 5 Input Considerations
    1. 5.1  Input Stage Schematic – The Classic LM339 Family
    2. 5.2  Input Stage Schematic - New B and TiB Devices
    3. 5.3  Differences Between the Classic, B and Tib Die Devices
    4. 5.4  Input Voltage Range
    5. 5.5  Input Voltage Range vs. Common Mode Voltage Range
    6. 5.6  Reason for Input Range Headroom Limitation
    7. 5.7  Input Voltage Range Feature
    8. 5.8  Both Inputs Above Input Range Behavior
    9. 5.9  Negative Input Voltages
      1. 5.9.1 Maximum Input Current
      2. 5.9.2 Phase Reversal or Inversion
      3. 5.9.3 Protecting Inputs from Negative Voltages
        1. 5.9.3.1 Simple Resistor and Diode Clamp
        2. 5.9.3.2 Voltage Divider with Clamp
          1. 5.9.3.2.1 Split Voltage Divider with Clamp
    10. 5.10 Power-Up Behavior
    11. 5.11 Capacitors and Hysteresis
    12. 5.12 Output to Input Cross-Talk
  9. 6 Output Stage Considerations
    1. 6.1 Output VOL and IOL
    2. 6.2 Pull-Up Resistor Selection
    3. 6.3 Short Circuit Sinking Current
    4. 6.4 Pulling Output Up Above Vcc
    5. 6.5 Negative Voltages Applied to Output
    6. 6.6 Adding Large Filter Capacitors To Output
  10. 7 Power Supply Considerations
    1. 7.1 Supply Bypassing
      1. 7.1.1 Low VCC Guidance
      2. 7.1.2 Split Supply use
  11. 8 General Comparator Usage
    1. 8.1 Unused Comparator Connections
      1. 8.1.1 Do Not Connect Inputs Directly to Ground
      2. 8.1.2 Unused Comparator Input Connections
      3. 8.1.3 Leave Outputs Floating
      4. 8.1.4 Prototyping
  12. 9 PSpice and TINA TI Models
  13. 10Conclusion
  14. 11Related Documentation
    1. 11.1 Related Links
  15. 12Revision History

7.1 Supply Bypassing

The supply must be free of noise and transients to avoid false transitions. The recommended supply bypass capacitor is a 0.1uF ceramic capacitor. The capacitor must be placed as close to the supply pins as possible to a solid ground. Because the output is open-collector, the supply pin only supplies current for the comparator quiescent current, so load transient currents are minimal. Further bypassing must be at the pull-up resistor if the resistor is located remotely. The GND pin must be returned to a solid ground as the pin can contain fast output load transients.