Power Integrations, Inc.

Munadir Aziz Ahmed

Arthur Brian Odell

Jinyuan Tian

Rajko Duvnjak

Aditya Jayant Kulkarni

A power converter including a controller to control a synchronous rectifier (SR) switch. The controller includes a request control circuit and a discharge prevention circuit. The request control circuit is configured to generate a request signal in response to an output of the power converter. The request control circuit generates a secondary control signal to control the SR switch. The discharge prevention circuit is configured to prevent a parasitic capacitance discharge of a power switch caused by a turn on of the SR switch. The discharge prevention circuit is further generates a prevent signal to disable the secondary control signal from control of the synchronous rectifier switch when a period of the request signal is greater than a first time threshold, and enable the secondary control signal to control the synchronous rectifier switch when the period of the request signal is less than a second time threshold.

Discharge prevention of the power switch in a power converter

A primary controller comprising a control circuit coupled to determine a mode of operation and to generate a first mode of operation signal and a second mode of operation signal. The control circuit coupled to generate a control signal in response to the first mode of operation signal or the second mode of operation signal, the control signal causes a delay time to enable a turn ON of a power switch after a turn OFF of a clamp switch. The control circuit coupled to output a clamp drive signal to control the clamp switch and comprises a delay circuit coupled to receive the first mode of operation signal and the second mode of operation signal, wherein the delay circuit is coupled to apply a first delay time or a second delay time to the control signal, the second delay time being longer than the first delay time.

Mode operation detection for control of a power converter with an active clamp switch

A primary controller configured for use in a power converter comprising a control circuit configured to determine a mode of operation of the power converter in response to a drive signal of a power switch. The control circuit further configured to generate a control signal in response to a signal representative of the mode of operation of the power converter, wherein the control signal represents a delay time to enable a turn on of the power switch after a turn off of a clamp switch. The control circuit further configured to generate a clamp drive signal to control the clamp switch. The primary controller further comprises a drive circuit configured to generate a drive signal to enable the power switch to transfer energy from an input of the power converter to an output of the power converter.

An auxiliary converter coupled to an output of a main power converter comprising an auxiliary switch, a timing circuit, and an energy transfer element. The auxiliary switch coupled to the output of the main power converter. A timing circuit coupled to receive a control signal from a controller of the main power converter, wherein the controller regulates the output of the main power converter, the timing circuit configured to output an auxiliary drive signal to control switching of the auxiliary switch in response to the control signal. The energy transfer element coupled to the auxiliary switch, wherein the energy transfer element is configured to transfer energy from the output of the main power converter to a supply of the controller, the supply provides operational power for the controller of the main power converter.

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San Mateo, CA, United States of America

Munadir Aziz Ahmed