Patent ID: 6519167
Filing Date: 2003-02-11
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 linear 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, and a voltage-controlled current source coupled to the switched variable for charging a capacitor with a current proportional to the switched variable to generate the linear ramp voltage and for discharging the capacitor when the switched variable is turned off such that the frequency of the PWM signal is substantially constant.