Bootstrap Capacitor Detection Circuit for DC-DC Converter Safety

The patent applies preliminary action by performing a discharge operation on the bootstrap voltage node before the upper gate switch is activated. The controlling unit detects the voltage at the bootstrap voltage node and discharges it if it exceeds a threshold value, preventing excessive power from damaging the upper gate switch before it starts operating. This proactive measure eliminates the harmful effect before it can cause damage.

The patent implements feedback by using the controlling unit to continuously monitor the voltage at the bootstrap voltage node and adjust the discharge operation accordingly. The controlling unit detects whether the voltage exceeds the threshold and dynamically controls the switching between charging and discharging states, creating a closed-loop control system that ensures the upper gate switch operates within safe voltage limits.

The patent applies universality by designing the controlling unit to perform multiple functions: it not only controls the charging and discharging operations of the bootstrap voltage node but also detects the voltage status and determines whether the bootstrap capacitor is connected normally. By integrating these multiple functions into a single controlling unit, the patent avoids adding separate dedicated detecting circuits, thereby improving reliability while minimizing the increase in device complexity.

The patent merges the detection function with the control function by integrating the voltage detection capability into the existing controlling unit. Rather than adding a separate detecting circuit, the controlling unit is designed to simultaneously perform both control operations (charging/discharging) and detection operations (voltage monitoring and connection status determination), thereby reducing overall circuit complexity while achieving reliable capacitor connection detection.