low-power BiCMOS Op Amp with integrated current mode charge pump

An operational amplifier with an integrated current mode charge pump is presented. This operational amplifier functions with a 4µA single-supply above-the-rail input and rail-to-rail output. Having an integrated charge pump greatly simplifies the amplifier design while providing an increased dynamic range over other rail-to-rail amplifiers. The current mode charge pump limits the power loss associated with feedthrough current found in most voltage mode designs. The resulting amplifier achieves a bandwidth of 54KHz, while consuming less than 10µW.