SLYT710B september   2017  – august 2023 LM22670 , LM25145 , LM2696 , LM3100 , LM3150 , LM3475 , LM3485 , LM5017 , LM5116 , LM5119 , LM5140-Q1 , LM5145 , TPS40040 , TPS40057 , TPS40170 , TPS51116 , TPS53014 , TPS53219A , TPS53355 , TPS54325 , TPS54336A , TPS543B20 , TPS543C20 , TPS543C20A , TPS54478 , TPS54610 , TPS54620 , TPS548A20 , TPS548D22 , TPS54A20 , TPS56121 , TPS56C215 , TPS62097 , TPS62130 , TPS82130

 

  1.   1
  2. 1 Overview
  3. 2 Voltage mode
  4. 3 Voltage mode with voltage feed-forward
  5. 4 Peak current mode
  6. 5 Average current mode
  7. 6 Emulated current mode
  8. 7 Internally-compensated advanced current mode (ACM)
  9. 8 Hysteretic control mode
  10. 9 Constant on-time
  11. 10Constant on-time with emulated ripple mode
  12. 11DCS-Control™: Direct control with seamless transition into power-save mode
  13. 12Direct connection to the output capacitor (D-CAP™)
  14. 13D-CAP+™
  15. 14D-CAP2™
  16. 15D-CAP3™
  17. 16D-CAP4™

8 Hysteretic control mode

The simplest control scheme. The PWM (SW) on-time (TON) is terminated when the feedback voltage is greater than a reference-high threshold and the off-time (TOFF) is terminated when the feedback voltage is less than a reference-low threshold. No compensation components are required. The PWM switching frequency is not controlled and varies with load current and delivers higher efficiency at lighter loads.

When to use: When fast transient response is required. There is no clock-signal time delay to initiate the ramp. A certain amount of ripple is required at the output from the output capacitor’s ESR.

Popular devices: LM3475, LM3485

Learn more: LM3485 Hysteretic PFET Buck Controller Data Sheet

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