The bootstrap circuit in Section 3.1 is similar to the power supply of the high-side gate driver. Through reuse, this power supply can reduce the cost. As shown in Figure 3-5, VCC is the power pin of the high-side gate driver and this solution removes a high-voltage diode (D1) and RC (C7, R6).

The solution shown in Figure 3-5 increases a load for the power supply of the gate driver, so it is necessary to pay attention to the impact of the gate driver. Increasing the current-limit resistance (R4) can reduce the impact. This solution still has the limitation because the isolated comparator power supply is dependent on the half-bridge circuit operation.