A low noise CLASS AB operational amplifier with high voltage output capability by 180 nm BCD process

Abstract

In this work, a low noise CLASS AB operational amplifier, which can output high voltage, has been fabricated by a 180 nm BCD process. For the objective of achieving low noise, the bipolar junction transistor (BJT) input stage with the base current compensation structure is employed. Experimental results show that the low noise amplifier’s equivalent input current and voltage noise are 3.2 pA/sqrt (Hz) and 16.73 nV/sqrt (Hz) separately, and the rising and falling slew rates are 10.40 MV/s and 6.67 MV/s separately. With the die area of 0.629 mm2, the amplifier’s power consumption is 18.3 mW, which flows 60 μA on the 5 V low power supply and 600 μA on the 25 V high power supply.