CMOS micro-power output stage for integrated voltage references

A CMOS micro-power, class-AB output stage with high current-drive capability for integrated voltage references is presented. A weak-inversion MOS translinear-loop ensures that the harmonic mean of the push and pull currents equals a constant bias current. It can source/sink 20 mA with only 15 (mu)A quiescent current, thus achieving very high power efficiency. It operates from a 2.5 V power supply and is stable for capacitive loads up to 2 nF.