TCS37209 datasheet(18/88 Pages) OSRAM

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Datasheet, Public

Page 17

[v5-00] 2023-Nov-27

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TCS3720 − Detailed Description

In the “concurrent” operating mode, ALS and proximity

measurements run at the same time, with the ALS measurement

“paused” while the proximity measurement is running. When

the device is operating non-synchronously, the ALS and

proximity measurements start after AEN=PEN=PON=1. When

the device is operating synchronously (i.e. the ALS and

proximity measurements are triggered by an external VSYNC

signal) the ALS and proximity start timing is determined by the

following:

• For ALS, AVSYNC_EN=1 enables synchronous mode and

ASD defines the delay from VSYNC until the ALS

measurement begins.

• For proximity, PVSYNC_EN=1 enables synchronous mode

and PSD defines the delay from VSYNC until the proximity

measurement begins.

AWTIME defines the ALS repetition period. In non-synchronous

mode, the subsequent ALS cycle will begin at the end of the

AWTIME period. In synchronous mode, the subsequent ALS

cycle will occur on the first VSYNC after the end of the AWTIME

period, plus the delay defined by ASD.

PWTIME defines the proximity repetition period. In

non-synchronous mode, the subsequent proximity cycle will

begin at the end of the PWTIME period. In synchronous mode,

the subsequent proximity cycle will occur on the first VSYNC

after the end of the PWTIME period, plus the delay defined by

PSD.

Figure 19 shows the ALS and proximity timing during

concurrent mode.

In concurrent mode, it is important to configure ALS hold (CFG2

(0xA7), bit 3) correctly in order to avoid a situation where ALS

is constantly interrupted and cannot complete in a timely

manner. It is recommended to pause ALS only during the time

the emitter is pulsing (CFG2, bit 3=1). This may result in a slight

increase in ALS data noise, but the trade-off is a shorter pause

time.

TCS37209 Datasheet(PDF) 18 Page - OSRAM GmbH