摘要
提出一种适合微传感器读出电路的高精度折叠共源共栅放大器.基于斩波技术和动态元件匹配技术,降低了折叠共源共栅放大器的噪声和失调,采用低阻节点斩波的方法和低压共源共栅电流镜扩大了放大器可处理的输入信号带宽和输出电压摆幅.芯片在0·35μm2P4M CMOS工艺下设计并流片,测试表明在3·3V的典型电源电压和100kHz的斩波频率下,斩波放大器具有小于93·7μV的输入等效失调电压典型值,19·6nV/Hz的输入等效噪声,开环增益达83·9dB,单位增益带宽为10MHz.
A low-noise,low-offset folded-cascode amplifier for micro-sensor applications is presented. Low 1/f noise and offset are achieved by employing a chopper and dynamic element matching. The input signal bandwidth and output swing are extended with the use of the low impedance node chopping technique and a low-voltage cascode mirror structure. The chip has been realized in 0. 35μm 2P4M CMOS technology. The amplifier features an open-loop gain of 83. 9dB and a GBW of 10MHz. The measured typical residual input offset is less than 93.7μV, and the equivalent input low frequency noise is 19.6nV/√Hz at a chopping frequency of 100kHz and supply voltage of 3.3V.
