20 µA Maximum, RRIO, Zero Input Crossover Distortion Single Op Amp

The AD8505/AD8506/AD8508 are single, dual, and quad micro-power amplifiers featuring rail-to-rail input/output swings while operating from a single 1.8 V to 5 V power supply or from dual ±0.9 V to ±2.5 V power supplies. Using a new circuit technology, these amplifiers offer zero input crossover distortion (excellent PSRR and CMRR performance) and low bias current while operating with a supply current of less than 20 μA per amplifier. This amplifier family offers the lowest noise in its power class.

This combination of features makes the AD8505/AD8506/AD8508 amplifiers ideal choices for battery-powered applications because they minimize errors due to power supply voltage variations over the lifetime of the battery and maintain high CMRR even for a rail-to-rail input op amp. Remote battery-powered sensors, handheld instrumentation, consumer equipment, hazard detection (for example, smoke, fire, and gas), and patient monitors can benefit from the features of the AD8505/AD8506/AD8508 amplifiers.

The AD8505/AD8506/AD8508 are specified for both the industrial temperature range of −40°C to +85°C and the extended industrial temperature range of −40°C to +125°C. The AD8505 single ampli-fier is available in a tiny 5-lead SOT-23 package. The AD8506 dual amplifier is available in 8-lead MSOP and 8-ball WLCSP packages. The AD8508 quad amplifier is available in 14-lead TSSOP and 14-ball WLCSP packages. The AD8505/AD8506/AD8508 are members of a growing series of zero crossover distortion op amps offered by Analog Devices, Inc., including the ADA4505-1/ ADA4505-2/ADA4505-4, that operate from a single 1.8 V to 5 V supply or from dual ±0.9 V to ±2.5 V power supplies.

Applications

* Pressure and position sensors

* Remote security

* Bio sensors

* IR thermometers

* Battery-powered consumer equipment

* Hazard detectors

* PSRR: 100 dB minimum

* CMRR: 105 dB typical

* Very low supply current: 20 μA per amplifier maximum

* 1.8 V to 5 V single supply or ±0.9 V to ±2.5 V dual supply

* Rail-to-rail input/output

* Low noise: 45 nV/√Hz at 1 kHz

* 2.5 mV offset voltage maximum

* Very low input bias current: 1 pA typical