A Low Dropout Voltage Regulator with Enhanced Transconductance Error Amplifier and Small Output Voltage Variations

A low dropout (LDO) voltage regulator with small output voltage variations and the ability of wide load current range support is proposed in this paper. In thisLDO design, a recycling folded cascode operational transconductance amplifier (RFC OTA) is used as an error amplifier. This OTA structure has high transconductanceand therefore high power efficiency. The designed LDO is simulated in 0.18 CMOS standard technology and hassmall output voltage variations about 9 mV for load current in the range of 0-50 mA. Simulation results show a favorable transient response behavior with 1.2 μs rise timeand 183 mV dropout voltage for current changing in the desirable range. It’s shown that the LDO structure can support 0-150 mA load current range with reasonable output voltage variations. In addition, with the smaller load current ranges, the dropout voltage will be higher and the output voltage variations will be smaller

Keywords:

low noise , transient response , power consumption , buffer , load current changes