Abstract: An operational amplifier for a pipeline analog-to-digital converter (ADC). The operational amplifier includes a cascaded chain of differential amplifiers, each differential amplifier including resistive-averaged common mode feedback to produce a common mode voltage for the differential amplifier, a particular differential amplifier of the chain having the highest gain of the gains of the differential amplifiers. The operational amplifier has one or more feedback paths each including a compensation capacitor to compensate the operational amplifier.

Abstract: A pipeline analog-to-digital converter (ADC) includes cascaded stages for resolving at least one bit of an analog voltage. Each stage has an analog input, one or more reference voltage inputs, and one or more digital outputs. The analog voltage is coupled to the analog input of the first stage. Each stage but the last has an analog output connected to the analog input of the next stage, and includes an operational amplifier that has one or more differential amplifiers having a common mode voltage. The pipeline ADC includes a reference generator to generate the one or more reference voltages for the stages. The reference generator includes a circuit to track the common mode voltage of the differential amplifiers such that the generated reference voltages are relative the common mode voltages of the differential amplifiers.