A wide input range capacitor-free LDO circuit

A wide input range LDO circuit is proposed and designed based on the Xintang 0.35uBCD process in this paper. Without an external output capacitor, the designed LDO has a stable 5 V output voltage at an input range of 5-16 V input. The LDO has low overshoot voltage and fast recovery time. Meanwhile, design improvements have been made to the bandgap reference generator. Adopting an amplifier-free structure, this bandgap reference generator can stably generate a reference voltage of 1.24 V with a temperature coefficient of 10.58 ppm/°C. The LDO circuit can drive a maximum load of 30 mA. When the load is 30 mA, the LDO has a power suppression ratio of 83.01 dB at 1 KHz. It has a high loop gain, and the phase margin reaches 65°.