The design of ideal diode

Abstract

This article describes a P-channel MOSFET ideal diode circuit. The P-channel MOSFET on-resistance that connects the input and output is only 100mΩ in the circuit. In order to ensure the drop voltage from the input to the output is equal to V1(when I1 = 2A, V1 = 256mV), the circuit uses a high-gain amplifier to adjust the gate voltage of the P-channel MOS transistor(MP0). And the circuit also uses a high side current sensing comparator to limit the current that flows through the P-channel MOSFET. The maximum forward current achieves 2A, and the maximum reverse leakage current is 2μA. Simulation results using a 0.5μm BCD process are presented and discussed.