公开(公告)号：US20170237347A1

公开(公告)日：2017-08-17

申请号：US15585028

申请日：2017-05-02

Applicant: Intersil Americas LLC

Inventor： Michael Jason HOUSTON ,  Steven Patrick LAUR

IPC: H02M3/157 ,  H02M1/08

Abstract: The system and method creates a substantially constant output voltage ripple in a buck converter in discontinuous conduction mode by varying the on-time of a pulse width modulator (PWM) signal driving the buck converter when the buck converter is operating in discontinuous conduction mode. A first signal is generated that is a function of the switching frequency of the buck converter. This signal is low-pass filtered and compared with a second signal that is a function of the switching frequency of the buck converter when operating in continuous conduction mode and with constant PWM on-time. The output signal generated by the comparator is a signal that is equal to the ratio of the first signal and the second signal. The on-time of a voltage controlled oscillator is controlled by the output signal, the oscillator signal causing the on-time of the PWM signal to vary in a controlled fashion.