LDO design for wide power supply range and high PSRR
To meet strict requirements which need high voltage input range and power supply noise rejection ability in industrial and automotive electronics fields,a Low Dropout Linear Regulator(LDO)with wide power supply range and high Power Supply Rejection Ratio(PSRR)is designed.A new type of high voltage pre-regulation circuit is proposed,which improves the linear regulation and temperature drift of internal low voltage power supply(LV_AVDD)by using the negative feedback current and Cascode Cross-Coupled BJT structure.At the same time,the PSRR of LDO is further improved by the pre-regulation circuit.The whole circuit is composed of high voltage pre-regulation module and LDO loop module,and is designed based on 0.18 μm BCD process.Simulation results show that when the input power supply range is 10-40 V and the temperature range is-40-125℃,the output of LV_AVDD is 5.574 V,the temperature coefficient is 1.358×10-5℃-1,the linear regulation is 0.763 mV/V.The LDO output voltage is 3.325 V,and the low frequency PSRR reaches-120.1 dB.
万方数据
维普
