National Semiconductor Corporation

Jeffry Mark Huard

Shu-Ing Ju

Jayendar Rajagopalan

Rajarshi Paul

A system and method are disclosed for providing an active current assist with analog bypass for a switcher circuit. An active current assist circuit is coupled to a buck regulator circuit, which includes a switcher circuit, an inductor circuit and a capacitor circuit. The active current assist circuit includes an active current analog bypass control circuit and a current source. The active current analog bypass control circuit receives and uses current limit information, voltage error information, and drop out information to determine a value of assist current that is appropriate for a current operational state of the buck regulator circuit. The active current analog bypass control circuit causes the current source to provide the appropriate value of assist current to the buck regulator circuit.

System and method for providing an active current assist with analog bypass for a switcher circuit

The invention relates to a switching regulator with an error amplifier circuit and a feed-forward circuit. The error amplifier circuit provides an error signal by amplifying the difference between a feedback signal and a reference signal. The feed-forward circuit level-shifts the output of the error amplifier based on the feed-forward input signal and a scaling factor. The resulting adjusted error signal includes both feed-back and feed-forward signal components. A PWM comparator is employed to compare the adjusted error signal to a ramp signal. Switched-mode regulation is performed based on the PWM comparator output. In addition, buck-boost mode transition smoothing circuitry may also be employed to smooth the buck-mode/boost-mode transition in a buck-boost switching regulator.

Feed forward control of switching regulator

A buck (with boost) switcher is provided that adds boost functionality to a buck switcher without compromising the buck's performance with extra series-coupled switches nor requiring a second inductor. The switcher has an integrated circuit that is capable of receiving a power supply voltage and a mode signal and generating on separate outputs either a boost voltage or a buck voltage based on the power supply voltage and the mode signal. The mode signal corresponds to one of a buck mode and a boost mode. The switcher also has a single inductor that is coupled to the integrated circuit and is capable of being used by the integrated circuit to generate the boost voltage (or a high voltage capable current) in the boost mode and to generate the buck voltage in the buck mode.

Method and system for adding boost functionality to a buck switcher with minimal cost

The invention relates to a differential amplifier with internal compensation. The invention also relates to a regulator controller and a regulator which includes such an amplifier. The amplifier includes a preamplifier circuit and a gain circuit. The frequency response of the amplifier is based in part on internal compensation within the preamplifier circuit. The internal compensation of the differential amplifier includes a low frequency zero that is provided by the preamplifier circuit.

Growing community of inventors

Puyallup, WA, United States of America

Jeffry Mark Huard