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
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- 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™
4 Peak current mode
Pulse-width modulation (latch output) is accomplished by comparing a voltage error signal (VE) and a ramp waveform (VS) derived from the output current. The ramp is initiated by the clock signal. This mode offers fast response to output current changes. However, it can be susceptible to noise sensitivity at low duty cycles due to leading-edge current spike. It uses type-2 compensation addressing a single-pole power stage for externally compensated devices.
When to use: When a fixed, predictable switching frequency is needed with a lower parts count than the externally-compensated, double-pole voltage mode. Peak current mode uses a single zero compensator, which is easier to design than voltage mode’s double-zero compensator.
Popular devices: TPS54620, TPS62913, LM5140-Q1
Learn more: Understanding and Applying Current-Mode Control Theory
