1 µA Micropower CMOS Operational Amplifier

The AD8502/AD8504 are low power, precision CMOS operational amplifiers featuring a maximum supply current of 1 μA per amplifier. The AD8502/AD8504 have a maximum offset voltage of 3 mV and a typical input bias current of 1 pA operating rail-to-rail on both the input and output. The AD8502/AD8504 can operate from a single-supply voltage of +1.8 V to +5.5 V or a dual-supply voltage of ±0.9 V to ±2.75 V.

With its low power consumption, low input bias current, and rail-to-rail input and output, the AD8502/AD8504 are ideally suited for a variety of battery-powered portable applications. Potential applications include bedside monitors, pulse monitors, glucose meters, smoke and fire detectors, vibration monitors, and backup battery sensors.

The ability to swing rail-to-rail at both the input and output helps maximize dynamic range and signal-to-noise ratio in systems that operate at very low voltages. The low offset voltage allows use of the AD8502/AD8504 in systems with high gain without creating excessively large output offset errors. The AD8502 and AD8504 offer an additional benefit by providing high accuracy without the need for system calibration.

The AD8502/AD8504 are fully specified over the industrial temperature range (−40°C to +85°C) and the extended industrial temperature range (−40°C to +125°C). The AD8502 is available in an 8-lead, SOT-23 surface-mount package. The AD8504 is available in a 14-lead TSSOP surface-mount package.

Applications

* Portable equipment

* Remote sensors

* Low power filters

* Threshold detectors

* Current sensing

* Supply current: 1 μA maximum/amplifier

* Offset voltage: 3 mV maximum

* Single-supply or dual-supply operation

* Rail-to-rail input and output

* No phase reversal

* Unity gain stable