A fast transient response voltage mode buck converter with an adaptive ramp generator

This paper proposes a new concept of adaptive ramp generation to enhanced the transient response of PWM voltage mode buck converter. Based on a simple ramp slope controller, the proposed adaptive ramp generator can output ramp with different slopes to accelerate duty ratio adjustment so as to reduce the voltage variations (voltage spikes) and the transient recovery time. A PWM voltage mode buck converter with the proposed adaptive ramp generator was implemented using 0.18 μm CMOS process, which achieves an output variation of 131 mV and a recovery time of 36 μs, better than 186 mV and 43 μs of a conventional PWM voltage mode buck converter.