SAR ANALOG-TO-DIGITAL CONVERTER HAVING VARIABLE CURRENTS FOR LOW POWER MODE OF OPERATION

摘要

A successive approximation analog-to-digital converter includes a capacitor array having a plurality of switch capacitors therein with varying weights, each having a common plate connected to a common node and a switched plate. A SAR controller samples an input voltage on said capacitor array in a sampling phase and redistributes the charge stored therein in a conversion phase by selectively increasing the voltage on select capacitors of the capacitor array in accordance with a SAR conversion algorithm. Circuitry controls the sampling of the input voltage by the capacitor array and is responsive to at least one applied bias current. The at least one applied bias current operates at a first level responsive to a first mode of operation of the SAR ADC and operates at a second level responsive to a second mode of operation of the SARADC.