Photoelectric signal converter and analog-to-digital conversion circuit

A photoelectric signal converter and its simulating digital converting circuit are provided. An photoelectric signal converting circuit comprises a detecting module, a first P type metal-oxide- semiconductor transistor, a first N type metal-oxide-semiconductor transistor, a first switch unit and an output module. Wherein, the first P type metal-oxide-semiconductor transistor forms a phase inverter structure with the first N type metal-oxide-semiconductor transistor. The first switch unit is arranged between an input terminal and an output terminal of the phase inverter structure and controls switch-on/off according to a first control signal. The output module is coupled with an output terminal of the phase inverter to count duration that an input voltage signal is higher than a reference voltage signal and generate digital data. The present invention can reduce impact of threshold voltage drift on a comparator.