Picor Corporation

Other

John P Clarkin

Patrizio Vinciarelli

Jeffrey B Van Auken

Claudio Tuozzolo

Dimitry Goder

George J Schuellein

Alex Gusinov

Aiman Alhoussami

Andreas Gerasimos Ladas

Chris R Swartz

Robert M Lanoue

A switching power converter comprising an inductor and one or more switches and configured to operate in a discontinuous operating mode comprises a clamp circuit connected to the ends of the inductor for trapping energy in the inductor during a clamp period. The clamp circuit comprises a first and a second clamp switch connected in series, the clamp circuit arranged and configured to block a voltage of either polarity when both switches are OFF; conduct a current of either polarity when both switches are ON; conduct uni-directionally in one direction when one of the clamp switches is ON; and conduct uni-directionally in the other direction when the other one of the clamp switches is ON. A controller turns the one or more switches ON and OFF to transfer energy from the input to the inductor and from the inductor to the output during an energy transfer phase.

Apparatus and methods for control of discontinuous-mode power converters

Buck and boost power converter topologies and methods of converting power are provided. One method provides switching power conversion circuitry including an inductor and switches and clamp circuitry connected across the inductor. Control circuitry operates the switches and the clamp circuitry in a series of converter operating cycles which may include: (a) an energy transfer interval for transferring energy input to output via the inductor; (b) an energy recovery phase, during which the inductor current oscillates transitioning from substantially zero to a negative value, from the negative value to a positive value, and from the positive value toward zero; and (c) a clamp phase, during a portion of which the clamp circuitry is ON, energy is trapped in the inductor, the inductor current is negative, and is not zero at the end of the clamp phase.

Zero voltage switching energy recovery control of discontinuous PWM switching power converters

A primary-side sampled feedback system includes a sample acquisition phase during which the voltage across the clamp capacitor is sensed as a measure of the primary-reflect output voltage. One end of the clamp capacitor is ground-referenced during the sample acquisition phase. The sample circuitry, which may include a transformer-coupled input for receiving the gate drive of the secondary switch, may use primary side, secondary-side, or primary and secondary side signals to generate the sample acquisition control pulse and clamp switch drive signal. The sample acquisition control pulse occurs when the secondary current reaches its minimum or zero.

Primary side sampled feedback control in power converters

In some implementations, a method of dynamically maintaining a device's operation within a safe operating area (SOA) may include sensing instantaneous voltage and current of the device; determining, based on the sensed instantaneous voltage and current, a value that represents a power dissipated in the device; using the determined dissipated power and a model of thermal behavior of the device to model a junction temperature of the device; and controlling operation of the device based on the modeled junction temperature. A programmable SOA circuit including sensing, scaling, filtering, and controlling functions may be packaged on a single die or in a package with a power transistor.

Dynamic safe operating area control

A primary-side sampled feedback system includes a sample acquisition phase during which the voltage across the clamp capacitor is sensed as a measure of the primary-reflect output voltage. One end of the clamp capacitor is ground-referenced during the sample acquisition phase. The sample circuitry, which may include a transformer-coupled input for receiving the gate drive of the secondary switch, may use secondary-side or primary and secondary side signals to generate the sample acquisition control pulse and clamp switch drive signal. The sample acquisition control pulse occurs when the secondary current reaches its minimum or zero.

High-performance low-power isolated bootstrapped gate drive apparatus and methods are disclosed for driving high-side and floating transistors. The gate drivers use edge-triggered capacitive-coupled inputs. The gate drivers may include detection and delay circuitry to facilitate zero-voltage-switching of the high side or floating transistor and providing more robust rejection of false triggering. A capacitively coupled differential input edge triggered gate driver provides exceptional immunity to false triggering. The gate drivers may be used in transformer coupled drive circuits using transformers that need only support coupled pulses wide enough to be recognized as an edge by the input circuit.

Capacitively coupled floating gate driver

A switching power supply produces a regulated output voltage. An output inductor is connected at one end to a power switch circuit having a duty cycle. The other end of the output inductor has a regulated output voltage. A voltage feedback circuit produces a voltage feedback signal representative of the regulated output voltage. A current feedback circuit produces a composite signal representative of inductor current, the composite signal having an ac component and a dc component. An error amplifier produces an error signal representative of the difference between a reference voltage and the voltage feedback signal. A pulse width modulator comparator compares the error signal to a composite signal representing a summing of the voltage feedback signal with a current sensing signal representative of output inductor current, the composite signal having an ac component and a dc component. The comparator output results in a gate drive signal that controls the duty cycle of the power switch circuit to maintain the regulated output voltage.

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Coventry, RI, United States of America

John P Clarkin