AS7221 datasheet(14/36 Pages) AMSCO

14 / 36 page

Page 14

ams Datasheet

Document Feedback

[v1-01] 2016-Dec-08

AS7221 − Detailed Description

XYZ Chromatic White Color Sensor

The XYZ chromatic white/color sensor, part of the AS7221

Cognitive Light Engine (CLE), is a next-generation digital color

sensor device. The sensor contains an integrating

analog-to-digital converter (16-bit resolution ADC), which

integrates current from photodiodes. Upon completion of the

conversion cycle, the result is transferred to the corresponding

data registers. Transfers are double-buffered to ensure integrity

of the data is maintained.

Standard observer interference filters realize the XYZ response,

which enables both a no life-time drift and very high

temperature stability. Note the AS7221 LGA package contains

an internal aperture that provides a package field of view

(PFOV) of ± 20.5°. External optics can be used as needed to

expand or reduce this built in PFOV.

AS7221 Inputs

Figure 16:

VDDHV Based Settings for Inputs

Note(s):

1. For VDDHV <= 3.6V, VDDHV and VDD should be tied together.

2. With external dividers connected to 0-10V inputs, the max voltage to the device input is 2V.

For the AS7221, dimming can be accomplished from either the

input pin (0_10V_DIM) or network command via the UART. For

network commanded dimming, using the AS7221 Smart

Lighting Command set, the UART interface is used.

Local hardware inputs can be provided by, for example, a slide

control dimmer. The 0-10V DIM analog input signal is

downscaled by the AS7221 with an internal voltage divider and

converted to a 10 bit digital value, 0V=full dimming, 10V=no

dimming. When using the internal voltage divider the voltage

at the VDDHV pin has to be higher than 10V.

If a second supply is not available, VDDHV and VDD are tied

together and the downscale has to be done by an external

resistor divider. The maximum range in the downscaled input

is limited to 2V. Hence to accept a full range 10V signal the input

resistor divider has to be 5:1 ratio. Dependent on the level at

pin VDDHV the Smart Lighting Manager automatically selects

either the internal or the external voltage divider. Refer to the

Figures above and below. If the 0_10V_DIM pin is not used, an

external resister pull-up connecting it to VDDHV is

recommended.

VDDHV

Dimming

10.5-15V

Direct input for 0_10V_DIM, dimming input

2.97-10V (1)

External 5:1 resistor divider for 0-10V_DIM, dimming input (2)

AS7221 датащи(PDF) 14 Page - ams AG

AS7221 датащи(HTML) 14 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

датащи скачать

ссылки URL