Datasheet
Appendix C : General Application Guide for APDS-9005
The APDS-9005 is a low cost analog-output ambient light
photo sensor whose spectral response closely emulates
the human eyes. APDS-9005 consists of a photo sensor
that is able to produce a high gain photo current to a
sucient level that can be converted to voltage with a
standard value of external resistor. APDS-9005 can easily
be integrated into systems that use ADC input which is
available for sampling of the external source, as shown in
gure C1 below.
The amount of converted voltage, Vout, is mainly
dependant proportionally on the photo current which
generated by the brightness of the light shone on the
photo sensor and the load resistor used, RL. Increasing
the brightness of the light or/and the load resistor will
increase the output voltage.
Brightness is measured as “LUX” unit, which describes how
intense a light source that our eyes perceive. LUX meter
is the equipment for “LUX” measurement. Light sources
with the same LUX level appear at the same brightness to
the human eyes.
Selection of the load resistor RL will determine the
amount of current-to-voltage conversion in the circuit.
Light source e.g. uorescent light consists of ac noise
frequency of about 100Hz. A capacitor of 10uF, which
act as a low-pass lter, is recommended to add in parallel
with the load resistor to reduce the ripples.
Figure C1. Conguration of APDS-9005
APDS-9005
A/D
micro-
controller
1
2,3,4,5
6
Vcc
NC
Vout
R L
Light
C
Source
2.1 Optical Window Material
The material of the window is recommended to be poly-
carbonate. The surface nish of the plastic should be
smooth, without any texture.
The recommended plastic material for use as a window is
available from Bayer AG and Bayer Antwerp N. V. (Europe),
Bayer Corp.(USA) and Bayer Polymers Co., Ltd. (Thailand),
as shown in Table 2.
Table 2. Recommended Plastic Materials
Material number
Visible
light transmission Refractive index
Makrolon LQ2647 87% 1.587
Makrolon LQ3147 87% 1.587
Makrolon LQ3187 85% 1.587
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Data subject to change. Copyright © 2007 Avago Technologies Limited. All rights reserved. Obsoletes AV01-0598EN
AV02-0080EN - January 16, 2007