TCS34907FN datasheet(11/34 Pages) AMSCO

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ams Datasheet

Page 11

[v1-09] 2016-Jan-11

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TCS3490 − Functional Description

The TCS3490 device provides ambient light sensing and color

temperature sensing. The internal state machine manages the

operation of the device. It controls the ALS functionality and

power down modes. Average power consumption is managed

via control of variable endurance low power wait cycles.

The interrupt feature improves system efficiency by eliminating

the need to poll the sensor. Two interrupt sources (ALS, ALS

saturation) can activate the open drain output pin. Each

interrupt source is enabled independently. ALS interrupts

appear when upper or lower thresholds are exceeded for a

consecutive number of sample readings.

The advanced digital color light sensor portion of the TCS3490

contains a segmented circular photodiode array used for color

measurements. This architecture provides stable color sensing

independent of the incident angle of light. Four integrating

analog-to-digital converters (ADCs) integrate light energy from

photodiodes simultaneously.

Figure 17:

Simplified ALS State Machine

Communication with the device is

accomplished through a fast (up to 400

kHz) two wire I²C serial bus for easy

connection to a microcontroller or

embedded controller. The device

typically draws only 235

μA in color

operation and 1uA during power down.

Functional Description

Sleep

Start

Wait

RGBC

PON = 1

(0x80:b0)

PON = 0

(0x80:b0)

TCS34907FN Datasheet(PDF) 11 Page - ams AG