Patent ID: 11942940
Assignee: RENESAS ELECTRONICS AMERICA INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 7:
8. An apparatus comprising:
a controller configured to:
send an enable signal to a device to enable a low power state of the device, the device comprises a high side switching element and a low side switching element;
in response to the low power state of the device being enabled, send a three-level pulse width modulation (PWM) control signal to the device to drive the high side switching element and the low side switching element, wherein the three-level PWM control signal varies among a low level, a middle level, and a high level;
detect a lapse of a hand off time, wherein the hand off time is a duration in which the middle level of the three-level PWM control signal is sustained during the low power state of the device; and
in response to the detection of the lapse of the hand off time during the low power state of the device, use the three-level PWM control signal to operate a low side switching element of the device to charge a bootstrap capacitor of the device during the low power state of the device.