A High Performance LDO Design With Ultra-Low Dropout Voltage
Based on 0.35 μ m process,a Low Drop-out(LDO)voltage regulator is designed for portable electronics with the output voltage regulated at 1.8V.The designed circuit works under both of light-load and heavy-load conditions.The principle of LDO is briefly analyzed,and the working functions of key circuits are described in detail.The frequency compensation is realized by both adding the Miller compensation capacitor and increasing the off-chip capacitor's equivalent serial resistance(ESR).The feasibility of the design is verified by Cadence Spectre simula-tion.In low power mode,static current can be as low as 45 µ A.Under heavy load condition,the gain can achieve more than 65 dB,and the drop-out voltage can go below 50 mV.
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维普
