Low Power CMOS Chopper Preamplifier Based on Source-Degeneration Transconductors

This paper describes the design of a low-power, low-noise flicker CMOS chopper preamplifier for sensor signal conditioning. The core amplifier and the Gm-C output low pass filter of the proposed fully differential preamplifier are based on a source degeneration transconductor. The circuit was designed in a standard 0.18μm CMOS process with 1.8V supply voltage. It shows 42dB gain, 1 kHz bandwidth and a total power consumption of 84 μW. The proposed configuration achieves a noise efficiency factor of 4.6 and a total input-referred noise of 560 nV_rms integrated from 0.1 to 1 kHz.