Capella Microsystems Inc.

Wenbo Liang

Yuh-Min Lin

The ambient light sensor structure includes a power supply, a converter, and a pulse processing unit. The power supply provides a reference voltage interface, a high voltage interface and a low voltage interface. The converter includes a first current-to-pulse converter, a second current-to-pulse converter, a first light sensor and a second light sensor. The pulse processing unit comprises a signal subtraction component for circuit blocking, a counter, a digital-to-analog converter and a buffer by series connection. Without incident light, two light sensors would produce a dark current due to the material characteristics of the two photo diodes. Therefore, two current to pulse converters convert the dark current into a pulse signal and transmit the pulse signal to the signal subtraction component in order to cancel the dark current. By the method mentioned above, the dark current caused by the material characteristic of the two light sensors can be eliminated.

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Sindian, Taiwan

Wenbo Liang