SDAA108 October   2025 LM5171 , LM5171-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Circuit Differences Between Channels
  6. 3Design of External Error Amplifier Circuit
  7. 4Design of Additional OVP Circuit
  8. 5Common Settings
  9. 6Constant Current Operation with ISETx Clamping
  10. 7Summary
  11. 8References

Abstract

The LM5171 is a dual channel bidirectional average current mode controller. The two channels of LM5171 are independent. It is possible to configure the two channels as dual buck, dual boost or even one buck with one boost. However, some extra care must be taken when operating the two channels independently.

This application note shows the circuit differences between the two channels of LM5171. The missing features of CH2 for a complete converter are summarized when operating independently. The design requirements of the external circuits are analyzed. Two typical applications of using the two channels of LM5171 are discussed: two independent Constant Current/Constant Voltage (CC/CV) chargers and a bidirectional buck-boost converter. Detailed block diagrams are shown, and some design tips are provided.