QUALCOMM Incorporated
ADAPTIVE SWITCH BIASING SCHEME FOR DIGITAL-TO-ANALOG CONVERTER (DAC) PERFORMANCE ENHANCEMENT

Abstract:

Methods and apparatus for adaptively generating a reference voltage (V.sub.REF) for biasing a switch driver and corresponding switch in a digital-to-analog converter (DAC). The adaptive biasing scheme may be capable of tracking process, voltage, and temperature (PVT) of the DAC. An example DAC generally includes a plurality of DAC cells, each DAC cell comprising a current source, a switch coupled in series with the current source, and a switch driver coupled to a control input of the switch, the switch driver being configured to receive power from a first power supply rail referenced to a reference potential node; a regulation circuit comprising a first transistor coupled between the reference potential node for the DAC and the switch driver in at least one of the plurality of DAC cells; and a V.sub.REF generation circuit coupled to the regulation circuit and configured to adaptively generate a V.sub.REF for the regulation circuit.