Patent ID: 8373403
Filing Date: 2013-02-12
Classification: H02M,Y02B

Abstract:
1. In a power system having a converter comprising an input voltage, a synchronous switching circuit, an output voltage, and a synchronous switching control circuit having a driver designed to control the state of said synchronous switching circuit, a drive supply circuit coupled to said driver for controlling said synchronous switching circuit during a predetermined condition, said driver supply circuit comprising: a first input terminal for receiving pulse signals indicative of the predetermined condition; a first switching element connected to the first input terminal and operable to turn on when the pulse signals are supplied; a second input terminal for receiving a driver supply input voltage; an output terminal for providing a driver supply output voltage to the driver; time constant circuitry operable to begin charging to the driver supply input voltage upon turning on of the first switching element; and a second switching element connected to the output terminal and to the second input terminal and having a threshold voltage, the second switching element further operable to turn on when the threshold voltage is exceeded by the charge across the time constant circuitry, the time constant circuitry defining a time constant associated with an output voltage rise time of the converter, and such that full conduction of the second switching element is not performed until the time constant has elapsed.