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Priority claimed from US11/174,456external-prioritypatent/US7323672B2/en
Application filed by Capella Microsystems CorpfiledCriticalCapella Microsystems Corp
Publication of TW200703637ApublicationCriticalpatent/TW200703637A/en
Photometry And Measurement Of Optical Pulse Characteristics
(AREA)
Light Receiving Elements
(AREA)
Abstract
An ambient light sensor structure and its circuit characteristic are disclosed, and the ambient light sensor structure includes a power supply, a converter, and a pulse process unit. The power supply is to provide 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. Without incidence light, two light sensors would produce a dark current due to the material character of 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 subtract component in order to cancel the dark current. By the method mentioned above, the dark current that caused by the material characteristic of the two light sensors can be eliminated.