Amplifier with adjustable bias current

An amplifier having an adjustable current source which can be controlled to provide the requisite level of performance at reduced current consumption. The amplifier is first designed using one of many designs available and known in the art. A current source is then designed to provide adjustable bias current for the amplifier. The current source can be designed with MOSFETs which require no additional bias current and can accept a standard digital control signal. The current source can also be designed with active devices which are selected based on the logic of the control signals for ease of interface. The bias current determines the linearity and noise performance of the amplifier. The bias current is adjusted to provide the requisite level of performance while reducing power consumption. The current source can be designed to operate in discrete steps or to have substantially continuous current steps.