SLFS047C February   1984  – December 2024 TLC556 , TLC556M

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  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
    5. 5.5 Electrical Characteristics: VDD = 2V for TLC556C, VDD = 3V for TLC556I
    6. 5.6 Electrical Characteristics: VDD = 5V
    7. 5.7 Electrical Characteristics: VDD = 15V
    8. 5.8 Switching Characteristics
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram (Each Timer)
    3. 6.3 Feature Description
      1. 6.3.1 Monostable Operation
      2. 6.3.2 Astable Operation
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Designing for Improved ESD Performance
    2. 7.2 Typical Applications
      1. 7.2.1 Pulse-Width Modulation
        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 Pulse-Position Modulation
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.2 Pulse-Position Modulation

As shown in Figure 7-3, any of these timers can be used as a pulse-position modulator. This application modulates the threshold voltage and thereby the time delay of a free-running oscillator. Figure 7-4 and Figure 7-5 shows the output frequency and duty cycle versus control voltage.

TLC556 TLC556M Circuit for Pulse-Position Modulation
A. The modulating signal can be direct or capacitively coupled to CONT. For direct coupling, consider the effects of modulation source voltage and impedance on the bias of the timer.
Figure 7-3 Circuit for Pulse-Position Modulation