An Adaptive Voltage Scaling Buck Converter with Preset Circuit

An Adaptive voltage scaling (AVS) buck converter with Preset circuit (P-AVS), which can adaptively scale the output voltage fast, is presented. The voltage scaling loop in the proposed Pulse width modulation (PWM) buck with P-AVS is divided into coarse scaling loop and fine scaling loop, which can regulate the reference voltage adaptively according to load status. The coarse scaling loop can set quickly a coarse value of reference voltage according to the operation frequency of the load by a preset block, and the fine scaling loop is designed to scale voltage finely. The proposed P-AVS buck converter, with 3.3V input and 2MHz switching frequency, is fabricated in a 0.13 mu m standard CMOS process. The output voltage and the frequency of the load are designed from 0.7V to 1.5V and 30MHz to 120MHz respectively. Compared with a typical AVS buck, the proposed P-AVS converter can save 17 mu s scaling up from 0.7V to 1.1V.