CMOS class-AB current mirrors for precision current-mode analog-signal-processing elements

CMOS class-AB current mirrors for high-precision current-mode analog-signal-processing elements are described. The class-AB configuration allows us to reduce the offset error caused by device mismatch, the nonlinearity distortion, and power consumption. The offset error due to the device mismatch is greatly reduced by the reduction of the bias current. The class-AB current-mirror has less sensitivity to the mismatch since the bias current relative to the signal current can be reduced. The excellent precision is confirmed by Monte Carlo simulation and SPICE based on 1 /spl mu/m CMOS LSI parameters.