Patent ID: RE40915

Claim:
An apparatus for generating a regulated direct current (DC) output voltage comprising: a DC—DC converter coupled to a supply voltage, and being operative to generate a regulated output voltage derived from said supply voltage, said DC—DC converter having a pulse width modulation generator which generates a PWM switching signal that switchably controls operation of a switching circuit containing first and second electronic power switching devices coupled between respective first and second power supply terminals, a common node thereof being coupled through an inductor element to an output voltage terminal; and a controller for controlling the operation of said PWM generator, said controller including a sense amplifier unit having an input coupled to said first power supply terminal, a second input and an output, a current feedback resistor electrically coupled between said common output node and said second input of said sense amplifier unit, a variable impedance coupled to said output of said sense amplifier unit and to said second input of said sense amplifier unit, said variable impedance configured to vary in impedance in response to said output of said sense amplifier unit, a sample and hold circuit coupled to said variable impedance, and being operative to sample and hold current flowing through said variable impedance as a sensed current, and a sensed current correction circuit, coupled between said sample and hold circuit and said controller, and being operative to supply, to said controller, a correction current having a prescribed temperature-compensating relationship to said sensed current as sampled and held by said sample and hold circuit , wherein said correction current is a combination of said sensed current, a first compensating current and a second compensating current .