LED 아날로그 디밍을 위한 포토센서 설계

In this paper, a photosensor using a p-sub/n-well type photodetector has been designed. A photosensor consists of pixel, source follower, oscillator, sample-and-hold and switch MOS. After pixel reset, photodetector generated some output-signals according to input light intensity. The output-signal is delivered to the switch MOS through source follower and sample-and-hold circuits. Because the output voltage range according to the voltage is changed. The current flowing in a led will be change. The result of using the photosensor shows that the difference output voltage according to light intensity.