A Micropower Low Noise Integrated Operational Amplifier

Abstract

This paper describes a new integrated operational amplifier designed specifically for low standby power consumption. This amplifier is intended for use in portable instrument and telemetry equipment where low battery power drain is an important consideration. This high gain, low power, low noise operational amplifier is fabricated on a single silicon chip. Recent development of a low noise transistor process and a compatible high value resistor process led to its development. The highlights of its performance specifications are its high input impedance, low offset, low noise, and, for the first time in a commercially available operational amplifier, quiescent power consumption in the microwatt range. The circuit has excellent common mode and power supply rejection which, coupled with the high voltage process, insure operation over a supply voltage range of ±2.7 v to ±18 v. The amplifier, as shown in Figure 1, has a differential input and a single ended output. The general parameters of this amplifier are shown in Table 1.