TMD2755 datasheet(11/54 Pages) OSRAM

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[v3-00] 2023-Jan-02

TMD2755 − Detailed Description

Proximity

Proximity results are affected by three fundamental factors: the

integrated IR VCSEL emission, IR reception, and environmental

factors, including target distance and surface reflectivity. The

IR reception signal path begins with IR detection from a

photodiode and ends with the 14-bit proximity result in PDATA

adjusted to optimize performance. Offset correction or

cross-talk compensation is accomplished by adjustment to the

POFFSET register. The analog circuitry of the device applies the

offset value as a subtraction to the signal accumulation;

therefore a positive offset value has the effect of decreasing the

results.

Ambient Light Sensing, ALS

The ALS reception signal path begins as photodiodes receive

filtered light and ends with 16-bit results. Channel 0 contains a

photopic filter and channel 1 contains an infrared (IR) filter

which is used both for the proximity function and also to

accurately measure ambient light levels. Signals from both

photodiodes are simultaneously accumulated for a period of

time set by the value in ATIME before the results are available.

Gain is adjustable by either 128x or 1024x to facilitate operation

over a wide range of lighting conditions under dark glass with

low transmissivity. Based on the optical glass used on top of the

device, custom equations are empirically derived to calculate

the amount of ambient light using the ALS results.

Detailed Description

TMD2755 Datasheet(PDF) 11 Page - OSRAM GmbH