1-volt operational amplifier with rail-to-rail input and output ranges

A bipolar integrated operational amplifier (op amp), operating over nearly the full supply voltage range when the supply voltage is 1 V or more, has been designed with an input stage which can handle signals beyond the supply rails and an output stage which is able to operate within 10 mV of the supply rails. Characteristics of the op amp are 0.7-mV offset, 75-nV/ square root Hz noise, 450-kHz bandwidth, and 40-dB worst-case common-mode rejection ratio. The input and output stages are shown.< >