A self-tracking analog-to-
digital converter includes a digital-to-analog converter (DAC) adapted to provide a variable reference
voltage, a windowed flash analog-to-
digital converter (ADC) adapted to provide an
error signal ek corresponding to a difference between an input
voltage Vi and the variable reference
voltage, and
digital circuitry adapted to generate suitable control signals for the DAC based on the
error signal ek. More particularly, the
digital circuitry includes a first digital circuit adapted to provide a first function value f(ek) in response to the
error signal ek, the first function value f(ek) representing an amount of correction to be applied to the variable reference voltage. A second digital circuit is adapted to provide a counter that combines the first function value f(ek) with a previous counter state Nk to provide a next counter state Nk+1, the next counter state Nk+1 being applied as an input to the digital-to-analog converter. A third digital circuit is adapted to scale the previous counter state Nk by a factor M and combine the scaled counter state M·Nk with the error
signal ek to provide a digital output value Dk representing the input voltage Vi.