Multi-function sensor suits smartphone display screens

This sensor features ambient light, colour (RGB) sensing, and proximity detection with two advanced emitter drivers integrated within a compact 3.34 mm x 1.36 mm x 0.6 mm organic land grid array (OLGA) package.

The ambient light/colour sensing function provides four concurrent ambient light sensing channels (Red, Green, Blue, and Clear). A UV/IR blocking filter covers the RGB and Clear channels.

To manage display appearance, the architecture accurately measures ambient light while calculating illuminance and colour temperature.

The sensor is ideal for use with smartphone display screens that operate at a high refresh rate with high-frequency PWM brightness control and have low transmissivity.

These display features create extremely challenging operating conditions for a behind OLED ALS/proximity sensor: high speed shortens the blanking time in which the device can measure optical signals, while low transmissivity attenuates the signal reaching the sensor's photodiodes.

In typical implementations, the TCS3720 can reliably support a proximity sensing range of up to 5 cm while providing colour and illuminance measurements for granular optimization of the phone display's brightness and colour balance.