SBVA102 august   2023 TPS56837

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2D-CAP3 Control Architecture
    1. 2.1 Adaptive On-Time Control
    2. 2.2 D-CAP3 Control
  6. 3Large Duty Cycle Operation
    1. 3.1 Min Off-Time Performance of Buck Converters
    2. 3.2 On-Time Extension Function
  7. 4Bench Test and Comparison
    1. 4.1 Comparison Between TPS56837 and TPS56637
    2. 4.2 Comparison of On-Time Extension between TPS56837 and TPS568230
    3. 4.3 Load Transient Improvement by On-Time Extension
  8. 5Summary
  9. 6References
  10. 7Also From TI

Abstract

Most buck converters have a limited duty cycle. In order to obtain a larger duty cycle to support rated output at a lower input voltage, some converters reduce its frequency when the duty cycle is high. However, for those converters with D-CAP3™ (Constant On-time) control, it achieves this target through extending the on-time, which is the On-Time Extension (OTE) operation. This application note presents a detailed introduction to this large duty feature based on TPS56837, including the implementation of large duty, the performance and advantages of OTE in D-CAP3™ control mode.