ams TSL2740 light and proximity sensor

The TSL2740, from ams, combines an ambient light sensor (ALS) and a proximity light-to-digital sensor that approximates the human eye response to light intensity under varying lighting conditions. The 2 x 2 x 0.5 mm sensor features a wide dynamic range to operate effectively in a broad spectrum of lighting conditions, transforming light intensity to a digital signal output through a 1.8–V I²C interface.

The product performs proximity sensing by measuring reflected IR light emitted from an external LED. The proximity engine features automatic ambient light subtraction, as well as offset adjustment registers to compensate for unwanted IR energy reflection at the sensor at a range of up to 10 cm.

The device’s ALS sensor features two output channels: a visible channel and an IR channel. The visible channel has a photodiode with a photopic interferometric UV- and IR-blocking filter. The IR channel has a photodiode with an IR pass filter. Each channel has a dedicated integrating data converter that converts photodiode current into a 16-bit digital output that can be interfaced with a microprocessor.

Offering high sensitivity when detecting ambient light even at millilux-level intensity, the sensor is suitable for smart home assistants, smart watches and wearables, display backlight control, tablets, smartphones and medical diagnostics applications.