Patent ID: 6381154
Filing Date: 2002-04-30
Classification: H02M,H03F,H03K

Abstract:
A single-cycle response PWM controller receiving a reference voltage and putting out a PWM signal to control a switched variable operating from a supply voltage, the PWM controller comprising:an error integrating amplifier for integrating the difference between the reference voltage and the switched variable and for putting out an integrated error voltage, a zero crossing detector for determining the moment the integrated error voltage crosses zero, a comparator for comparing a ramp voltage to the reference voltage, a flip-flop for putting out a PWM signal, the flip-flop being selectively set by the zero crossing detector and selectively reset by the comparator, wherein the ramp voltage is generated by charging a capacitor with the switched variable through a resistor and discharging the capacitor when the switched variable is turned off such that the frequency of the PWM signal is substantially constant.