LDO Linear Regulator with High Stability Based on Full Feedback
Jingnan Liu · 2011
An LDO linear regulator with high stability based on novel structure was presented.The circuit was designed with full feedback mode based on rail-to-rail error amplifier.A buffer stage including slew-rate enhanced(SRE) circuit was designed,and multi-stage stepping double Miller capacitor compensation method was adopted.Results from simulation based on Chartered 0.35 μm CMOS process showed that the circuit had an output voltage varying from GND to Vdd following reference voltage,and an open-loop phase margin not less than 88° at a load current from 0 to 300 mA.In addition,the circuit achieved a transient response with 28 mV voltage variation and 0.5 μs settling time for a 50 mA load step.The output voltage accuracy of the regulator was improved,and the quiescent current,as well as noise and area,of the system was reduced by using full feedback network,instead of resistance feedback network.