Patent ID: 8154334

Claim:
An apparatus, comprising: a voltage regulator including an high side switching transistor and a low side switching transistor; a high side driver for controlling operation of the high side switching transistor; a low side driver for controlling operation of the low side switching transistor; a bootstrap capacitor for providing an operating voltage to the high side driver, the bootstrap capacitor charged to a predetermined level responsive to a supply voltage prior to application of a PWM control signal to the high side driver and the low side driver; and wherein the low side driver drives the low side switching transistor according to a process that charges the bootstrap capacitor to the predetermined level prior to application of the PWM control signal to the high side driver and the low side driver, the process maintaining the high side switching transistor in an off state and turning on the low side switching transistor for a first predetermined number of cycles and turning off the low side switching transistor for a second predetermined number of cycles and repeating the process for predetermined number of times during startup of the voltage regulator when a prebias load is applied to the voltage regulator until the bootstrap capacitor is charged to the predetermined level.