US 9,099,922 B2 · System and method for adaptive current limit of a switching regulator

Abstract

An adaptive current limiter including a conversion network and an amplifier network developing an adaptive current limit signal for use by a switching regulator to limit peak current through an inductor of the switching regulator. The switching regulator develops a pulse control signal for controlling switching of current through the inductor to convert an input voltage to an output voltage. The conversion network provides a limit value by applying a duty cycle of the pulse control signal to a reference value. The amplifier network is configured to develop the adaptive current limit signal based on the limit value. The conversion network may multiply the reference value by the duty cycle to develop the limit value. The amplifier network may include a current source providing a fixed reference current to an amplifier to establish a minimum level of the adaptive current limit signal.

Claims21

Dependent claims

An adaptive current limiter for a switching regulator, wherein the switching regulator develops a pulse control signal and adjusts a duty cycle of the pulse control signal to control switching of current through an inductor to convert an input voltage to an output voltage, the adaptive current limiter comprising:

a conversion network which is configured to provide a limit value based on applying the duty cycle of the pulse control signal to a reference value;
and
an amplifier network which is configured to provide an adaptive current limit signal using said limit value, wherein said adaptive current limit signal is used by the switching regulator to limit peak current through the inductor.

A switching regulator, comprising:

a switch network that is configured to switch current through an inductor using a pulse control signal to convert an input voltage to an output voltage;
a current sense network configured to develop a current sense signal indicative of current through said inductor;
a voltage sense network configured to develop a voltage sense signal indicative of said output voltage;
a first comparator configured to compare said current sense signal with an adaptive current limit signal to develop a first timing signal used for limiting a peak current through said inductor;
a second comparator configured to compare said voltage sense signal with a predetermined nominal value to develop a second timing signal;
a modulator configured to develop said pulse control signal using said first and second timing signals;
and
an adaptive current limiter which provides said adaptive current limit signal proportional to a duty cycle of said pulse control signal indicative of an output load of the switching regulator.

5 more elements

Dependencies are inferred from the claim text.

System and method for adaptive current limit of a switching regulator

Life of this patent

System and method for adaptive current limit of a switching regulator

Life of this patent

Abstract

Claims21