Bootstrap gate driver

A bootstrap gate driver, comprising:

• a load indication unit, configured to generate a load indication signal in response to a state of a load;
• a bootstrap gate-drive unit comprising a bootstrap capacitor, wherein the bootstrap gate-drive unit is configured to drive a switch-transistor circuit in response to an inputted pulse-width-modulation (PWM) signal, and the switch-transistor circuit has a high-side driving path and a low-side driving path;
• and
• a drive-control unit, coupled to the load indication unit and the bootstrap gate-drive unit, and configured to enable or disable the high-side driving path in response to the load indication signal,
• wherein when the load is in a light-loading state, a charging path of the bootstrap capacitor is not established, so as to disable the high-side driving path,
• wherein when the load is not in the light-loading state, the charging path of the bootstrap capacitor is established, so as to enable the high-side driving path,
• wherein the load indication unit comprises:
• a sample circuit, configured to detect the state of the load by a means of voltage/current sensing, so as to provide a detection signal;
• and
• a determination circuit, coupled to the sample circuit, and configured to compare the detection signal with a reference signal, so as to generate the load indication signal.