A dynamic buck converter with ultra fast response and low voltage ripples designed for DVS systems

This letter presents a buck converter for the dynamic voltage scaling systems where the supply voltage is dynamically adjusted to the minimum value required by the applications. A voltage controlled delay line based PWM controller is designed to simplify the structure for the purpose of energy saving. In order to speed up the transient response, the pseudo-continuous conduction mode and the pulse division technique are used. When the switching frequency f is 800kHz and the input voltage is 3.3V, the output voltage of the converter is dynamically modulated from 1.7V to 2.8V according to a changeable reference clock f_ref from 70MHz to 140MHz. A fast transient response of 5.27μs for a step voltage change from standby to the maximum operation is obtained. The output voltage ripple is less than 2mV.