一种增益提升和摆率增强的电流镜放大器
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摘要
针对低压低功耗条件下传统电流镜运算放大器电压增益和摆率严重降低的问题,提出了一种新型增益提升和摆率增强的CMOS电流镜放大器,并对其小信号增益和摆率进行了详细分析。理论分析表明,在不影响单位增益频率和相位裕度等小信号特性的同时,极大地提高了增益和摆率。仿真结果表明,与传统的CMOS电流镜放大器相比,该新型CMOS电流镜放大器的增益提高了15dB,正、负摆率分别提高到传统放大器的146倍和187倍。
A novel CMOS current-mirror operational amplifier with gain and slew rate enhancement was proposed to deal with the problems of voltage gain and slew rate degradation associated with conventional current-mirror operational amplifier under low supply voltage and low power consumption.The small signal gain and slew rate were detailed.Theory analyses showed that the gain and slew rate were boosted enormously without degrading small signal characteristics such as unity gain frequency and phase margin,etc.The simulation results showed that the gain was boosted by 15 dB and the positive and negative slew rates were raised to 146 and 187times respectively compared with that of the conventional CMOS current-mirror operational amplifier.
A novel CMOS current-mirror operational amplifier with gain and slew rate enhancement was proposed to deal with the problems of voltage gain and slew rate degradation associated with conventional current-mirror operational amplifier under low supply voltage and low power consumption.The small signal gain and slew rate were detailed.Theory analyses showed that the gain and slew rate were boosted enormously without degrading small signal characteristics such as unity gain frequency and phase margin,etc.The simulation results showed that the gain was boosted by 15 dB and the positive and negative slew rates were raised to 146 and 187times respectively compared with that of the conventional CMOS current-mirror operational amplifier.
引文
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[3]YAO L B,STEYAERT M,SANSEN W.A 0.8-V,8-μW,CMOS OTA with 50-dB gain and 1.2-MHz GBW in 18-pF load[C]∥Proceed 29th Europ Sol Sta Circ Conf.Estoril,Portugal.2003:297-300.
[4]LEE H,MOK P K T.A CMOS current-mirror amplifier with compact slew rate enhancement circuit for large capacitive load applications[C]∥IEEE Int Symp Circ&Syst.Sydney,NSW,Australia.2001,1:220-223.
[2]YAO L B,STEYAERT M S J,SANSEN W.A 1-V140-μW 88-dB audio sigma-delta modulator in 90-nm CMOS[J].IEEE J Sol Sta Circ,2004,39(11):1809-1818.
[3]YAO L B,STEYAERT M,SANSEN W.A 0.8-V,8-μW,CMOS OTA with 50-dB gain and 1.2-MHz GBW in 18-pF load[C]∥Proceed 29th Europ Sol Sta Circ Conf.Estoril,Portugal.2003:297-300.
[4]LEE H,MOK P K T.A CMOS current-mirror amplifier with compact slew rate enhancement circuit for large capacitive load applications[C]∥IEEE Int Symp Circ&Syst.Sydney,NSW,Australia.2001,1:220-223.