← 返回 JSSC 论文列表JSSC 2007第7期Analog Circuits0.7μm CMOSOp-Amp
A CMOS Chopper Offset-Stabilized Opamp
一种采用斩波技术的CMOS低失调运算放大器设计
1.5μV失调@16kHz斩波频率，1.3MHz单位增益带宽(50pF负载)，700μA@5V供电
斩波放大器失调稳定CMOS运算放大器采样保持电路低频路径
▸创新点1：采用低频路径斩波放大器技术，通过斩波调制有效抵消宽带放大器的输入失调电压，将残余失调降低至1.5μV以下（方法创新）
▸创新点2：引入采样保持电路(S&H)抑制高频斩波纹波，解决了传统斩波放大器输出纹波大的问题，提升信号纯净度（电路创新）
▸创新点3：对低频路径进行二次失调稳定设计，通过级联补偿进一步降低系统残余失调，实现多级误差校正（系统架构创新）
▸创新点4：在0.7μm CMOS工艺下实现1.3MHz单位增益带宽与50pF负载驱动能力，功耗仅700μA@5V，面积效率达3.6mm²（性能创新）
Abstract
In this paper, an offset-stabilized operational ampli- fier is described. The amplifier employs a chopper amplifier in a low frequency path to cancel the offset of a wide-bandwidth ampli- fier. A sample-and-hold circuit is used to reduce the chopper ripple, and the low frequency path is also offset-stabilized to further re- duce the residual offset. The amplifier has less than 1.5 V offset at a 16-kHz chopper frequency, a unity gain frequency of 1.3 MHz with a 50-pF load, and draws 700 A from a 5-V supply. The am- plifier was realized in a 0.7 m CMOS process, and has an effective chip area of 3.6 mm /50.