Integrating analog-to-digital converter

Claim 1

Analog-to-digital converter apparatus comprising: an integrator coupled to receive input analog signals to be converted to digital representations; comparator means coupled to the integrator for receiving an error signal therefrom and having an output line for supplying the result of a comparison of the error signal with an applied reference signal; flip-flop means responsive to signals from the comparator means for providing digital incremental time duration outputs corresponding to the analog signals, the flip-flop means having an input terminal and including internal circuitry making up a J-K flip-flop; means coupled to the flip-flop means for digitizing an incremental time duration output from the flip-flop means to provide an output digital indication of the magnitude and polarity of a corresponding input analog signal; a voltage reference source; switching means responsive to an output of the flip-flop means for selectively applying reference potentials from the reference source to the integrator; logic circuitry coupled between the comparator means output line and the input terminal of the flip-flop means for selectively controlling the application of signals from the comparator means to the flip-flop means input terminal; said logic circuitry including a logic gate for both directing an error signal from the comparator means to the flip-flop means and directing a reset signal to the flip-flop means; and separate ramp generating means including a ramp generator for generating ramp signals for application to the comparator means for comparison with the error signal from the integrator.