A sensor signal processor apparatus having good characteristics and providing an easy and simple interface for various sensors. The sensor signal processor apparatus includes a current source, a sensor, a ramp integrator, a comparator, and a controller. The current source generates a constant current according to a preset value, and the sensor outputs a sensor voltage using the current from the current source. The ramp integrator generates and outputs an integral voltage according to an input command, and the comparator compares the sensor voltage of the sensor with the integral voltage of the ramp integrator and outputting a result of the comparison. The controller controls the generating and outputting of the integral voltage of the ramp integrator according to the comparison result of the comparator.