Abstract: Analog-to-digital conversion apparatus provides high-resolution conversion of input signals. Summing elements combine an analog input signal and an analog offset signal to generate a residual signal. A first integrator element integrates the residual signal, and a second integrator processes the first integrator output signal to produce a second integrator output signal. A comparator processes the first and second integrator output signals to produce a digital offset signal, the second integrator output signal is converted into a digital representation, and output elements process the digital offset signal and second integrator output signal to produce a digital representation of the analog input signal.