A new structure of low-noise CMOS differential amplifier

A new structure of low-noise CMOS differential amplifier has been presented in this paper. The structure is mainly based on a load of common-gate MOSFETs with resistances in series at sources (CG-R load), which does not increase complication of the circuit. This structure decreases 1/f noise of the load by a (1 + g/sub m2/R) /sup 2/ coefficient, while keeps the voltage gain high. The simulation result for the given example reveals an average reduction of 90% for load noise at low frequencies, compared with current-mirror load (CM load).