LDO’s Design And Temperature Drift Research

LDOs have advantages including：Smaller size、low power consumption、high powersupply rejection ratio、and better linear transient response. Besides they are more efficient.Today in many of electronic products are increasingly high expectations for LDOs. Insome certain circumstances, demanding of temperature drift coefficient of LDO is critical.This paper firstly states the operational principle of a LDO, and secondly researchesand analyses all kinds of performance parameters of a LDO in detailed. Based onTSMC0.18um CMOS process, this paper proposes a high performance LDO. Theproposed LDO is simulated by spectre software. The simulation result shows as follows：the power supply is3V; the output voltage is1.8V; the drive capability is300mA; the lineregulation is less than0.5%/mV; the load regulation is less than0.5%/mA; and thetemperature drift coefficient is less than10ppm/℃. This paper also proposes the circuitlayout related with LDO’s circuit schematic at the same time.This paper proposes a kind of new circuit which could calibrate the temperature driftcoefficient in order to make sure that the temperature drift coefficient is low enough. Theresult of the chip samples shows that the proposed circuit is well effective and practical.