To provide a semiconductor sensor capable of obtaining high sensitivity digital output for reducing the influence of noise by accurately digitizing and outputting the sensor output with a simple circuit using CMOS technology, and particularly integrating the digitizing circuit with a sensor chip.
To digitize and take out the output of a sensor 11, first CMOS circuit 12a inputted with sensor output Vs and a second CMOS circuit 12b inputted with a triangular signal Vt are commonly connected to an output terminal with the same element parameter and disposed. The output OUT1 is inputted to a comparator 13 having two stages of CMOS inverters 13a, 13b to obtain a pulse width modulation output OUT2 pulsated by a predetermined logic threshold value. Further, the output OUT 2 is passed through an AND gate to be inputted with reference clock in response to the necessity to obtain digital output of pulse number corresponding to the pulse width.