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 Overview
- 2 Voltage mode
- 3 Voltage mode with voltage feed-forward
- 4 Peak current mode
- 5 Average current mode
- 6 Emulated current mode
- 7 Internally-compensated advanced current mode (ACM)
- 8 Hysteretic control mode
- 9 Constant on-time
- 10Constant on-time with emulated ripple mode
- 11DCS-Control™: Direct control with seamless transition into power-save mode
- 12Direct connection to the output capacitor (D-CAP™)
- 13D-CAP+™
- 14D-CAP2™
- 15D-CAP3™
- 16D-CAP4™
9 Constant on-time
A slight variation to hysteretic control minimizing frequency shift, but with a single voltage-threshold level, yet achieving fast transient response. The on-time is terminated by a one-shot on-timer and is proportional to the input voltage. The off-time is terminated when the feedback voltage falls below the reference-low threshold.
When to use: When fast transient response is required and a fixed or predictable switching frequency is not required. A certain amount of ripple is required at the output from the output capacitor ESR.
Popular devices: LM5017, LM2696, TPS54A20
Learn more: Controlling Output Ripple and Achieving ESR Independence in Constant On-Time (COT) Regulator Designs
