Abstract: 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.

Key words: chopper amplifier, low noise, low offset, micro-sensor