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AS7221

Functional Description

Datasheet

• PUBLIC

DS000479

• v4-00 • 2019-Jun-28

│ 15

Functional Description

7.1

Smart Lighting Manager

– Overview

The Cognitive Light

Engine (CLE) is the “brains” of the Smart Lighting Manager (SLM). The CLE

constantly processes information from the calibrated XYZ chromatic white/color sensor, Smart Lighting

Command Interface and control inputs to adjust and control PWM and 0-10 V channel outputs to

deliver the targeted light characteristics. AS7221 initial setup and ongoing parameter storage is

automatically done by software within the required external serial Flash memory, via SPI bus. Only

ams-verified models of Flash devices can be supported. A subset of supported devices is noted in the

UART Command Interface section of this document, which also provides a reference to the current list

of supported Flash memory devices. For the Flash memory overview please refer to Figure 30. A SPI

Flash device is a required operating companion to the AS7221. Figure 30 includes a partial list of

supported devices, which have been tested by ams. Using non-verified devices can cause

communication issues and may not be compatible. Flash timing is provided in Figure 28 and Figure 29

for debug purposes.

By sensing a sample of the mixed warm and cool CCTs as either a reflection from the diffuser or other

light-guide/optical light gathering technique, the AS7221 can support high precision multi-channel

tuning results from a lower cost dual- or single channel LED driver architecture. Please note, that non-

diffused applications require some form of reflective or other light gathering that delivers an adequate

sample of mixed light to the sensor. Care should be taken to fulfill the angle of incidence requirements

of the nano-optic filter set.

To support the growing need for more personalized or circadian-rhythm supportive lighting systems,

up to 16 scenes can be preset into flash memory to support autonomous CCT and brightness

adjustments, including programmable ramp/transition timing. Scene timing, targets and ramps are

programmable via the high-level Smart Lighting Command Set described in Section 10.

AS7221 Datasheet(PDF) 16 Page - OSRAM GmbH