SNOSDA4D June   2020  – November 2023 LM339LV , LM393LV , TL331LV , TL391LV

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1. 4.1 Pin Functions for TL331LV and TL391LV
    2. 4.2 Pin Functions: LM393LV
    3. 4.3 Pin Functions: LM339LV
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information for TL3x1LV
    5. 5.5  Thermal Information, LM393LV
    6. 5.6  Thermal Information, LM339LV
    7. 5.7  Electrical Characteristics, TL3x1LV
    8. 5.8  Switching Characteristics, TL3x1LV
    9. 5.9  Electrical Characteristics, LM393LV
    10. 5.10 Switching Characteristics, LM393LV
    11. 5.11 Electrical Characteristics, LM339LV
    12. 5.12 Switching Characteristics, LM339LV
    13. 5.13 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
    4. 6.4 Device Functional Modes
      1. 6.4.1 Open Drain Output
      2. 6.4.2 Power-On-Reset (POR)
      3. 6.4.3 Inputs
        1. 6.4.3.1 Rail to Rail Input
        2. 6.4.3.2 Fault Tolerant Inputs
        3. 6.4.3.3 Input Protection
      4. 6.4.4 ESD Protection
      5. 6.4.5 Unused Inputs
      6. 6.4.6 Hysteresis
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Basic Comparator Definitions
        1. 7.1.1.1 Operation
        2. 7.1.1.2 Propagation Delay
        3. 7.1.1.3 Overdrive Voltage
      2. 7.1.2 Hysteresis
        1. 7.1.2.1 Inverting Comparator With Hysteresis
        2. 7.1.2.2 Non-Inverting Comparator With Hysteresis
    2. 7.2 Typical Applications
      1. 7.2.1 Window Comparator
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Square-Wave Oscillator
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curve
      3. 7.2.3 Adjustable Pulse Width Generator
      4. 7.2.4 Time Delay Generator
      5. 7.2.5 Logic Level Shifter
      6. 7.2.6 One-Shot Multivibrator
      7. 7.2.7 Bi-Stable Multivibrator
      8. 7.2.8 Zero Crossing Detector
      9. 7.2.9 Pulse Slicer
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.2.9 Pulse Slicer

A Pulse Slicer is a variation of the Zero Crossing Detector and is used to detect the zero crossings on an input signal with a varying baseline level. This circuit works best with symmetrical waveforms. The RC network of R1 and C1 establishes an mean reference voltage VREF, which tracks the mean amplitude of the VIN signal. The noninverting input is directly connected to VREF through R2. R2 and R3 are used to produce hysteresis to keep transitions free of spurious toggles. The time constant is a tradeoff between long-term symmetry and response time to changes in amplitude.

If the waveform is data, it is recommended that the data be encoded in NRZ (Non-Return to Zero) format to maintain proper average baseline. Asymmetrical inputs may suffer from timing distortions caused by the changing VREF average voltage.

GUID-14C578E8-0300-4453-819C-77555656792F-low.gifFigure 7-18 Pulse Slicer

For this design, follow these design requirements:

  • The RC constant value (R2 and C1) must support the targeted data rate in order to maintain a valid tripping threshold.
  • The hysteresis introduced with R2 and R43 helps to avoid spurious output toggles.

Figure 7-19 shows the results of a 9600 baud data signal riding on a varying baseline.

GUID-4368F1EB-4917-43C2-8FEC-44466991207C-low.gifFigure 7-19 Pulse Slicer Waveforms