| 摘要 |
PURPOSE: A proximity sensor is provided to obtain relatively a low current signal with high resolution and a low offset by directly converting a photo diode current into a digital output. CONSTITUTION: A driver(206) selectively drives a light source part. A photo diode(202) supplies a photo diode current signal. An A/D converter(204) has an analog-digital-analog feedback. A controller(208) controls the A/D converter that includes the driver and the analog-digital-analog feedback. The photo diode current signal represents the luminance of the light that is detected by the photo diode. The light that is detected from the photo diode comprises light transmitted from the light source part. The digital output of the A/D converter eliminates ambient light which is detected by the photo diode. |
