Design Of Wide Input And Output Voltage Ultra-Low Quiescent Current High PSRR Low-Dropout Regulator

With the rapid development of power management technique, power managementchips have been widely used in portable electronics such as smart phone, tabletpersonal computer and so on. Low drop-out regulator which is characterized by smallfootprint, low noise, low power consumption, high PSRR（Power Supply RejectionRatio）, simple peripheral circuit and so on, has gain widely application in the powersupply system of the electronics.Based on the project of “Design technique research of power analog integratedcircuit” in Key Lab of High-Speed Circuit Design and EMC, Ministry of Education inXidian University, this paper focuses on the design of wide input and outputlow-dropout regulator in0.25m BCD process. There are two methods for outputvoltage that one is fix output voltage which has seven output voltage,1.5V,1.8V,2.5V,2.7V,3V,3.3V,5V, and that another is output adjustable from1.24V~20V. The dropoutvoltage is mere310mV under150mA load situation, which ensures high powerefficiency. High PSRR in1KHz of-70dB under150mA load makes the chip free fromthe influence of voltage ripple and noise. Standby time is long and quiescent powerdissipation is ultra-low for the sake of ultra-low quiescent current which is as low as18A. The accuracy of output voltage is as high as±2%in the temperature range of-40℃～+125℃, which indicates an excellent output performance. The pre-regulatorcircuit makes the internal core circuit operate under low supply voltage. The wideoutput voltage range is beneficial from the high voltage level shift circuit. A transientenhanced error amplifier is designed to improve the transient response of the chip. Anadaptive zero circuit has been put forward to maintain the stability of the chip under0~150mA load range. Over temperature protection circuit, over current protectioncircuit and short circuit protection circuit can keep the safe operation of the circuit.In the last, simulation and verification of the whole chip and its building blockshave been accomplished by EDA tools such as Cadence etc. The results indicate thatthe chip has accomplished all of its functions with excellent characteristic parameters.