Patent ID: 7969134
Filing Date: 2011-06-28
Classification: H02M,Y02B

Abstract:
1. A power supply controller comprising: a clock circuit configured to form a clock signal having a first period; a PWM block configured to receive the clock signal and form a PWM drive signal to control a current through an inductor in order to regulate an output voltage to a desired value, the PWM drive signal having the first period; a first input configured to receive a feedback signal that is representative of the output voltage; an error circuit configured to receive the feedback signal and form an error signal that is representative of a deviation of the output voltage from the desired value; a ramp generator configured to form a ramp signal wherein the ramp signal has the first period; a sense circuit configured to form a sense signal that is representative of an instantaneous value of the current through the inductor; a reference circuit configured to form a reference signal wherein the reference circuit is configured to vary a value of the reference signal responsively to the sense signal; a control circuit configured to selectively form a threshold signal substantially equal to one of the error signal or the reference signal responsively to a difference between the error signal and the reference signal; and a PWM comparator actively coupled to compare the ramp signal to the threshold signal to control an on-time of the PWM drive signal.