CPC H03K 3/012 (2013.01) [H03K 17/6871 (2013.01); H03K 2217/0063 (2013.01); H03K 2217/0072 (2013.01)] | 20 Claims |
1. An apparatus comprising:
a controller configured to:
detect a signal level of a three-level pulse width modulation (PWM) control signal, wherein the signal level varies among a low level, a middle level, and a high level;
enable a low power state of a device, the device comprising a high side switching element and a low side switching element driven by the three-level PWM control signal;
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, and in response to the three-level PWM control signal transitioning to the low level during the low power state of the device, use the three-level PWM control signal to activate the low side switching element to charge a bootstrap capacitor of the device during the low power state of the device.
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