SWITCHING REGULATOR USING ADAPTIVE SLOPE COMPENSATION WITH DC CORRECTION

摘要

A switching regulator using current mode control and adaptive slope compensation includes a DC correction circuit to introduce a DC correction signal to cancel the DC offset error generated by the slope compensation signal. In some embodiments, the DC correction signal is a function of the input voltage and the output voltage and is applied in response to the slope compensation signal being applied. In one embodiment, the DC correction signal is a linear function of the input voltage and the output voltage.

主权项

1. A switching regulator being configured to receiving an input voltage and to generate a regulated output voltage, the switching regulator controlling a high-side switch and a low-side switch based on a feedback control scheme to drive a switch output node for generating a switching output voltage, the switch output node being coupled to an LC filter to generate the regulated output voltage having a substantially constant magnitude on an output node, the switching regulator comprising:
a current mode feedback control circuit configured to generate a control signal to turn on or off the high-side switch and the low-side switch in response to a first signal indicative of the difference between a feedback voltage indicative of the output voltage and a first reference signal and in response to a second signal indicative of a sensed current of an inductor of the LC filter; a slope compensation circuit configured to provide a slope compensation signal as a function of the input voltage and the output voltage and for a given range of duty cycle values, the slope compensation signal being provided to the current mode feedback control circuit; and a DC offset correction circuit configured to generate a DC offset correction signal having a value being a function of the input voltage and the output voltage, the DC offset correction signal being provided to the current mode feedback control circuit, wherein the DC offset correction signal is applied in response to the slope compensation signal being applied and has a magnitude selected to cancel the DC offset error introduced by the slope compensation signal.