A configurable analog to digital converter (ADC) is provided. The configurable ADC includes a comparator receiving and comparing a first analog voltage signal to a second analog voltage signal V-DAC and outputting a signal C-OUT that is responsive to a result of the comparison, an integrator operating on C-OUT and outputting an N-bit value, a digital-to analog converter (DAC) converting the N-bit value to the second analog voltage signal V-DAC, and an integrator, the integrator including the N-bit memory, which is coupled to an arithmetic logic unit (ALU), the N-bit memory and ALU cooperating to perform operations using both the N-bit value and C-OUT. The configurable ADC is configured to operate in more than one mode selected from a plurality of selectable ADC modes.

An integrator including: a resistive element connected to an input terminal; an operational amplifier configured to receive, through the resistive element, an input signal that has been supplied to the input terminal; and a voltage regulator circuit connected to an intermediate node between the resistive element and the operational amplifier. The voltage regulator circuit has a first current source connected to the intermediate node, and a switch connected between the intermediate node and the first current source and selectively turning ON or OFF.