The family includes the TSL2540 and TSL2541 ambient light sensors and the TSL2740, a combined ambient light and proximity sensor.
The sensors detect light intensities as low as a few millilux – the equivalent of a clear night sky with no moonlight – and operate up to bright sunlight. The sensors enable automatic adjustment of LCD display backlighting or of indicator LEDs in response to changes in the brightness of the ambient light.
All three optical sensors are offered in the 2.0mm by 2.0mm by 0.5mm QFN package The TSL2541’s package is made with a special dark compound which makes the device almost undetectable when mounted under inked cover glass.
The TSL2540,TSL2541 and TSL2740 are equipped with separate photopic ambient light and infrared light sensing channels made with interferometric IR and photopic filters deposited directly on the silicon. The photopic channel approximates the human eye’s response to light intensity under widely varying lighting conditions and through very dark attenuated materials. The TSL2740 performs proximity sensing by measuring reflected IR light emitted from an external LED and operates at ranges of up to 10cm.
The TSL2540, TSL2541 and TSL2740 are available now in production volumes. Unit pricing is $0.44 for the TSL2540 and TSL2541 and $0.46 for the TSL2740 in an order quantity of 5,000 units. Evaluation kits for all three devices are now available.
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