Abstract: A differential charge pump with common mode and active regulators is presented. Either type of regulator may be used to improve the performance characteristics of the differential charge pump. The active regulator increases the output range of the differential amplifier. The common mode regulator establishes the common mode voltage of the differential charge pump. The common mode voltage is established independently from external circuitry and does not use a feedback path. The common mode regulator may also be used to establish a mid-rail voltage, which may be used to further improve the output range of the differential amplifier.

Abstract: An operational amplifier with selectable performance characteristics is provided. The operational amplifier provides a sleep mode (e.g., fully disabled) in addition to providing a number of different levels of awake operation (e.g., different performance characteristics). As such, the op-amp can allow a system to use only the power needed to obtain a required level of performance at any point in time. For example, the op-amp may be operated at a minimum power mode, an awake at mid-level power mode, or an awake at maximum power mode.