Patent ID: 7388764
Filing Date: 2008-06-17
Classification: H02M

Abstract:
1. A constant output current controller system for a switching regulator the system comprising: a transformer reset time detector with an input lead that is operable to receive a feedback signal derived from a transformer winding—and, wherein the transformer reset time detector computes a transformer reset time signal based in part on the feedback signal, and wherein the transformer reset time signal represents a duration of time until the feedback signal has decayed to approximately a steady rate; a calculator unit, that generates a combined signal by multiplying the transformer reset time signal by a current signal through a power switch; an error amplifier, which outputs a signal based on the difference between a reference signal and the combined signal, wherein the reference signal is sets by an output current level of the switching regulator; a comparator that is configured to compare the combined signal and at least one ramp signal; an oscillator, wherein the oscillator output includes jitter generated signal digitally as opposed to using an analog technique; a PWM controller module that outputs a PWM switching regulator control signal based on an oscillator output from the oscillator and an output from the comparator; and a gate drive module that receives the PWM switching regulator control signal and generates a corresponding gate drive signal operable for properly turning on or off the power switch of the switching regulator, wherein the gate drive signal turns the power switch on and off such that the output current level of the switching regulator remains constant.