A capacitance sensing device can include a reference circuit configured to connect to a reference capacitance, and to generate an electrical reference signal that varies over time according to the reference capacitance and a compare signal; a sense circuit configured to connect to a sense capacitance, and to generate an electrical sense signal that varies over time according to a sense capacitance; a compare circuit having compare inputs coupled to receive the sense signal and the reference signal, and a compare output that provides the compare signal; and a value generation circuit configured to generate an output value corresponding to the compare signal over a predetermined time period.