Patent ID: 6300818
Filing Date: 2001-10-09
Classification: H02M,Y10S

Abstract:
For use with a power supply having a semiconductor switch that exhibits a temperature-dependent electrical characteristic, a controller, comprising:a current sense circuit that employs said characteristic of said switch to derive a switch current signal;a temperature compensation circuit, including:an electrical component, locatable in thermal communication with said switch and having a temperature-dependent electrical characteristic that bears an inverse relationship to said characteristic of said switch, that generates an intermediate signal based on an actual temperature of said switch, anda signal conditioning circuit, coupled to said electrical component, that scales said intermediate signal to yield a compensation signal that counteracts temperature-dependent variations in said switch current signal;a comparison circuit that combines said switch current signal and said compensation signal to yield a temperature-compensated switch current signal;an output voltage error circuit, coupled to an output of said power supply, that biases said temperature-compensated switch current signal with an output voltage error signal; anda pulse-width modulation (PWM) controller, coupled to said comparison circuit and said output voltage error circuit, that develops a control signal for said power supply based on said temperature-compensated switch current signal and said output voltage error signal.