US 2014/0210433 A1 · NEGATIVE CURRENT SENSE FEEDBACK FOR REVERSE BOOST MODE

Abstract

Techniques for providing negative current information to a control loop for a buck converter in reverse boost mode. In an aspect, negative as well as positive current through an inductor is sensed and provided to adjust a ramp voltage in the control loop for the buck converter. The techniques may prevent current through the inductor during reverse boost mode from becoming increasingly negative without bound; the techniques thereby reduce settling times when the target output voltage is reduced from a first level to a second level. In an aspect, the negative current sensing may be provided by sensing negative current through a charging, or PMOS, switch of the buck converter. The sensed negative current may be subtracted from a current used to generate the ramp voltage.

Claims20

Dependent claims

An apparatus comprising:

a charging switch configured to selectively couple a first node of an inductor to a supply voltage;
a discharging switch configured to selectively couple the first node of the inductor to ground;
a control block configured to control the charging and discharging switches to set an output voltage at a load coupled to a second node of the inductor, the control loop comprising a comparator comparing a filtered error voltage to an adjusted ramp voltage;
a negative current sense block configured to sense negative current through the inductor, wherein the adjusted ramp voltage comprises an additive term that reduces the adjusted ramp voltage in response to negative current being sensed.

1 more element

Dependencies are inferred from the claim text.

Negative current sense feedback for reverse boost mode

Life of this patent

Negative current sense feedback for reverse boost mode

Life of this patent

Abstract

Claims20