The OP191, OP291 and OP491 are single, dual and quad micropower, single-supply, 3 MHz bandwidth amplifiers featuring rail-to-rail inputs and outputs. All are guaranteed to operate from a 3 volt single supply as well as ±5 volt dual supplies.Fabricated on Analog Devices' CBCMOS process, the OP191 family has a unique input stage that allows the input voltage to safely extend 10 volts beyond either supply without any phase inversion or latch-up. The output voltage swings to within millivolts of the supplies and continues to sink or source current all the way to the supplies.Applications for these amplifiers include portable telecom equipment, power supply control and protection, and interface for transducers with wide output ranges. Sensors requiring a rail-to-rail input amplifier include Hall effect, piezo electric, and resistive transducers.The ability to swing rail-to-rail at both the input and output enables designers to build multistage filters in single-supply systems and maintain high signal-to-noise ratios.The OP191/OP291/OP491 are specified over the extended industrial (-40°C to +125°C) temperature range. The OP191 single and OP291 dual amplifiers are available in 8-pin plastic DIPs and SO surface mount packages. The OP491 quad is available in 14-pin DIPs and narrow 14-pin SO packages. Consult factory for OP491 TSSOP availability.