Operation voltage testing circuit and method

An operation voltage testing method, comprising:

• generating a first voltage signal according to a first current signal by a voltage generating circuit, such that a photoelectric conversion unit generates a second current signal corresponding to the first voltage signal;
• generating a second voltage signal corresponding to the second current signal by a current-to-voltage conversion circuit;
• and
• receiving the second voltage signal, and selectively adjusting and outputting the first current signal according to the second voltage signal and a threshold value by a processing circuit, such that the voltage generating circuit selectively adjusts the first voltage signal according to the first current signal.

An operation voltage testing circuit, comprising:

• a processing circuit configured to generate a first current circuit;
• and
• a voltage generating circuit configured to generate a first voltage signal with a first voltage level according to the first current signal, such that a photoelectric conversion unit generates a second current signal corresponding to the first voltage signal,
• wherein the processing circuit is further configured to adjust and output the first current signal when the second current signal is smaller than a current signal outputted by the photoelectric conversion unit under a condition that the photoelectric conversion unit operates under an operation voltage, such that the voltage generating circuit generates the first voltage signal with a second voltage level, and the second voltage level is higher that the first voltage level.