Sensors Expo 2018: Low-Power Optical Sensors Are Highly Sensitive

As shown at Sensors Expo in San Jose, CA in booth #232, ams’ family of ambient light and proximity sensors boast high sensitivity, low-power, and a small package size. The family includes the TSL2540 and TSL2541 ambient light sensors and the TSL2740, a combined ambient light and proximity sensor.

 

The family delivers very high sensitivity when detecting ambient light at an intensity as low as a few millilux – the equivalent of a clear night sky with no moonlight. Featuring a wide dynamic range, they operate effectively in lighting conditions ranging from bright sunlight to a dark room, and behind inked cover glass. The sensors enable automatic adjustment of LCD display backlighting or of indicator LEDs in response to changes in the brightness of the ambient light.

 

The three sensors come in a miniature 2 mm x 2 mm 0.5 mm low-profile QFN package. The TSL2541’s package is made with a special dark compound that 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. Programmable proximity offset adjustability compensates for crosstalk effects from the IR LED in relation to proximity events at a range 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. For sample requests or more specs, datasheets are available. Last week, ams demonstrated these optical solutions at Sensors Expo in booth 232.