A subtractor circuit can be fabricated within an integrated circuit (IC) and can be configured to draw a difference output node to a voltage proportional to a difference between two received N-bit binary numbers. The subtractor circuit includes sets of N inputs that receive N-bit binary numbers, each set of N inputs indexed by an integer bit number “n.” The subtractor circuit includes two sets of scaled capacitors, each capacitor of one set connected to an nth input of the corresponding set of N inputs and to the difference output node. Each scaled capacitor has a capacitance equal to 2(n)*a unit capacitance (CUNIT). The subtractor circuit includes a reference capacitor connected to ground and the difference output node, and a reset circuit configured to draw, in response to a received RESET signal, the difference output node to ground.