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AS73211

General Description

Datasheet

• PUBLIC

DS000556

• v3-01 • 2018-Feb-07

65

│ 3

1

General Description

The AS73211 is a low power, low noise integrated color sensor. Three channels convert light signals

via photodiodes to a digital result and realize a continuous or triggered measurement. In front of the

three photodiodes there are optical filter mounted for X-, Y- and Z-signals respectively. The irradiance

responsivity can be set in a range of 12 steps by a factor of two for each step. The conversion time is

internally controlled over a wide range of 15 steps by a factor of two for each step. With the input pin

(SYN) the conversion time can be externally controlled to adapt the measurement to the given

environment and time base.

With its irradiance responsivity factor and conversion time the AS73211 supports an overall huge

dynamic range up to 3.43E+10 (resolution multiplied by gain range). It achieves an accuracy of up to

24-bit signal resolution (internal via I²C and shifter 16 bit) with an irradiance responsivity per count

down to 0.5pW/cm².

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For high robustness at high sensitivity, the AS73211 has an inherent ripple rejection of the

50Hz / 60Hz external disturbances. Automatic Power Down (sleep function) between subsequent

measurements offers operation with very low current consumption. Further, a synchronized mode and

other control modes adjustable by user programming can be used. The supported operating modes of

the AS73211 are:

●

CMD Mode

– single measurement and conversion (controlled via I²C interface),

●

CONT Mode

– continuous measurement and conversion (periodically recurring measuring

cycles) start and stop controlled via I²C interface,

●

SYN[x] Modes - synchronized measurement and conversion:

●

[SYNS Mode] synchronization of start via control signal at pin SYN,

●

[SYND Mode] synchronization of start and stop of measuring cycles via control signal at

pin SYN.

The conversion data is accessed by the I²C interface with programmable slave addresses via

16-bit / 400 kHz fast mode. The measurement of the actual conversion time for an external triggered

measurement can be performed. The measurement modes will not affect the settings of the irradiance

responsivity and conversion time. Further, the converter supports functions like Power Down and

Standby, therefore it is suitable for mobile applications. Based on the high flexibility the AS73211 is

suitable as an optical converter for three different wave-lengths. The device achieves a high dynamic

range in back light applications and in the measurements of integral intensity of pulsed light. That

makes the color sensors excellently suited for photometry applications (brightness, color coordinate

and/or color temperature), for determining current values for control of spectrally mixed LED light

sources or as sensors for display and (back)light calibration and mobile devices for light

measurement. The AS73211 contains an integrated temperature sensor for rough compensation of

the thermic behavior of light sources. The device is available in a small SMD package.