Method and apparatus for a data converter with a single operational amplifier

摘要

A data converter (10) includes an analog input element (12), an operational amplifier (14), a first reference input element (18), a second reference input element (22), and a control element (34). The analog input element (12) operably couples the analog signal to a first input (13) of the operational amplifier (14). The first and second reference input elements (18 & 22) respectively couple a first signal (16) and a second signal (22) to a first input of the operational amplifier (14). The control element (34) generates the control signal based on an output of the operational amplifier (14) to force the first input node (13) to be equivalent to the second input node (15) of the operational amplifier (14). The data converter (10) also includes an analog-to-digital converter (26) that allows the circuit to perform a sigma-delta conversion.