Analog-to-digital converter circuit e.g. for computer tomograpy has logic circuit which detects number of times charge is removed from integrating capacitor

摘要

The circuit includes an operational amplifier (46) with an integrating capacitor (44). A charge subtracting circuit (36) is selectively coupled to the inverting input (47) and the output (49) of the operational amplifier. A digital logic circuit (66) tracks the number of times a charge is removed from the integrating capacitor by the charge subtraction circuit. A residue quantization circuit detects a residual charge in the integrating capacitor, and provides an additional output bit accordingly. Independent claims are included for further analog-digital converter circuits and a method of converting an analog input signal into a number of binary output bits.