A high voltage charge pump circuit for H bridge high side drive

In this paper, based on the theory of switched capacitance, a charge pump circuit is designed for the high-edge drive of H-bridge. In order to meet the process requirements, a voltage regulator circuit with input voltage VIN-5V is designed as a floating power supply. A high edge differential pressure detection circuit, a high frequency oscillator circuit, and a cross-coupled two-stage charge pump circuit are also designed. The circuit was designed using 0.35 `m BCD technology, and the layout was completed and sent to the foundry. The simulation results show that the output of the oscillator is 20MHz when the input voltage varies from 5V to 40V. VIN-5V regulator outputs a stable voltage lower than 5V input. The output voltage of the charge pump follows the linear output of the input, and always remains greater than the input voltage of about 5V, the maximum load capacity is 5mA, and the output ripple is 329mV. The output frequency of the oscillator circuit is 20MHz.