Patent ID: 7710092

Claim:
A switched mode power supply comprising: at least one power switch adapted to convey power between input and output terminals of said power supply; and a digital controller adapted to control operation of said at least one power switch responsive to an output measurement of said power supply, said digital controller comprising: a digital-to-analog converter (DAC) adapted to provide a variable reference voltage; a windowed flash analog-to-digital converter (ADC) adapted to provide an error signal e k corresponding to a difference between the output measurement and the variable reference voltage; a first digital circuit adapted to generate a first function value f(e k ) in response to the error signal e k , the first function value f(e k ) representing an amount of correction to be applied to the variable reference voltage; a second digital circuit adapted to provide a counter that combines the first function value f(e k ) with a previous counter state N k to provide a next counter state N k+1 , the next counter state N k+1 being applied as an input to the DAC; and a third digital circuit adapted to scale the previous counter state N k by a factor M and combine the scaled counter state M·N k with the error signal e k to provide a digital output value D k representing the output measurement; a digital filter providing a digital control output based on a difference between the digital output value D k and a reference value; and a digital pulse width modulator providing a control signal to said at least one power switch, said control signal having a pulse width corresponding to said digital control output.