Voltage to frequency converter

A voltage to frequency converter includes an input signal integrator, a level detector connected to the output of the integrator, clock-signal-controlled logic illustratively comprising a D-type clocked flip-flop circuit connected to the output of the level detector, and a reference signal switch which applies a positive or negative reference signal to the integrator depending upon the logic level of the output of the logic. The polarity of the reference signal applied to the integrator is continuously switched causing the output of the integrator to move alternately in a positive and negative direction. Positive integration cycles are thus continuously opposed by negative integration cycles. The clock controlled logic forces each integration cycle to be an integral multiple of a clock signal pulse length in duration. The output of the logic is a pulsed signal 1aving a pulse rate or frequency proportional to the input signal voltage. The duty cycle of the logic output pulses is representative of the input signal polarity. In one embodiment, the output pulses from the logic are counted and the result represents a true time integral, in digital form, of the input signal over the counting time period.