Successive approximation analog-to-digital conversion with gain control for tuners

摘要

A method and system for implementing a gain control with fine resolution and minimal additional circuitry. The fine digital gain control may be deployed in conjunction with a coarse switched gain at the front end of a sampling receiver. The fine digital gain control mechanism is configured to receive an input signal and moderate gains applied to the received input signal. The output of a low noise amplifier (LNA) is connected to a switched attenuator which provides fine gain stepped gain control. The output of this stage is connected to the switch stage whose output is connected to a charge redistribution successive approximation register digital-to-analog converter (SAR ADC) configured to convert an analog waveform into a digital representation.