Texas Instruments Corporation

Fairchild Semiconductor Corporation

Christopher David Bridge

Laszlo Balogh

James Garrett

William M Andreycak

This document discusses, among other things, a regulator circuit. The regulator circuit can controllably connect a first voltage to an inductor using a first switch and can controllably connect a second voltage to the inductor using a second switch. The first switch can be turned off and the second switch can be turned on for a duration proportional to a difference between the first voltage and a third voltage, divided by the first voltage. The first switch can be turned off and the second switch can be turned on for a duration proportional to the third voltage divided by the first voltage. One of the first or third voltages can correspond to a desired output voltage.

Switch-mode regulator including hysteretic control

In an embodiment, a power converter system includes a plurality of variable frequency power converters and a plurality of synchronization circuits. Each variable frequency power converter has a switching frequency. Each synchronization circuit is associated with a respective one of the plurality of variable frequency power converters. A control circuit is coupled to and coordinates the plurality of synchronization circuits. The plurality of synchronization circuits and the control circuit are operable to synchronize the switching frequencies of the variable frequency power converters to each other. Each synchronization circuit is operable to: receive a first input signal indicative of the beginning of a switching period for the associated variable frequency power converter; receive a second input signal indicative of the end of the switching period for the associated variable frequency power converter; generate a first output signal for directing a pulse width modulation of the associated variable frequency power converter; and generate a second output signal for coordinating a phase relationship with another variable frequency power converter in the system.

Synchronizing frequency and phase of multiple variable frequency power converters

A controller for a switching power supply having first and second synchronous rectifiers that minimizes the reverse recovery time and body diode conduction losses of each of the synchronous rectifiers. The controller includes a first controller that predicts the optimal turn-on and turn-off time of the first synchronous rectifier as a function of voltage measurements of the previous switching cycle and the timing of the pulse width modulator signal in the current switching cycle. The controller also includes a second controller that predicts the optimal turn-on and turn-off time of the second synchronous rectifier as a function of voltage measurements of the previous switching cycle and the timing of the pulse width modulator signal in the current switching cycle.

Control circuit for synchronous rectifiers in DC/DC converters to reduce body diode conduction losses

A DC-to-DC converter to convert a first DC voltage to a second DC voltage includes a first switch connected to input the first DC voltage, a second switch, the first switch and the second switch being controlled by an input signal to generate the second DC voltage, the first switch and the second switch being connected to a control reference, and a control circuit to control the delay of the input signal by monitoring the control reference around an optimal delay point.

Control method to reduce body diode conduction and reverse recovery losses

A power supply having a transformer-coupled power converter cascaded with a buck power converter. The transformer-coupled power converter operates in a free-running mode at a nearly 100% maximum duty cycle to convert an input voltage to an intermediate voltage. The buck power converter produces a regulated output voltage from the intermediate voltage. The power supply further includes a pulse width modulation (PWM) controller employing leading-edge modulation of complementary control signals used to control buck switches in the buck converter. The PWM controller is synchronized to primary-side free-running switches of the transformer-coupled power converter by a synchronization signal that is fed-forward across an isolation boundary via a signal transformer. The power supply also may also employ a soft-switching technique to reduce switching losses.

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Bedford, NH, United States of America

Christopher David Bridge