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 4-/spl mu/A 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, designed with a dual-well BiCMOS process, achieves a bandwidth of 54 kHz while consuming less than 10 /spl mu/W.