Patent ID: 7538535
Filing Date: 2009-05-26
Classification: H02M

Abstract:
1. A DC-to-DC converter having error voltage ripple compensation for extending bandwidth in the feedback loop thereof, comprising: a pulse width modulation (PWM) generator, wherein the PWM generator controls the DC-to-DC converter and charges and discharges an inductor; a feedback loop filter/amplifier having an input coupled to an output of the DC-to-DC converter; a ripple compensation voltage capacitor; a first current source coupled to the ripple compensation voltage capacitor, wherein the first current source charges the ripple compensation voltage capacitor when the PWM generator charges the inductor; a second current source coupled to the ripple compensation voltage capacitor, wherein the second current source discharges the ripple compensation voltage capacitor when the PWM generator discharges the inductor; a high pass filter and compensation scaler having an input coupled to the ripple compensation voltage capacitor; and a voltage adder having a first input coupled to an output of the feedback loop filter/amplifier, a second input coupled to an output of the high pass filter and compensation scaler, and an output coupled to an input of the PWM generator; wherein a ripple compensation voltage from the output of the high pass filter and compensation scaler and a feedback loop error voltage from the output of the feedback loop filter/amplifier are added together in the voltage adder such that ripple voltage on the feedback loop error voltage is substantially reduced to the input of the PWM generator.