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Application Note 1741
Author: Xiaoying Shi
ISL76671 Low Power, <100 Lux Optimized, Analog Output
Ambient Light Sensor Evaluation Hardware User Guide
Description
The ISL76671 is a low light optimized analog output sensor. In
normal operation, the device is intended to be mounted behind
a smoked glass/plastic bezel which normally significantly
attenuates received light. The ISL76671 will typically saturate
at full scale with an incident illumination of around 150 lux,
which is a fair deal lower than normal indoor ambient light
conditions (2k to 10k lux).
The ISL76671EVAL1Z evaluation board is an RoHS compliant
evaluation board prepared to speed up part evaluation. Note
that the sensing range for this device is from 0.01 lux to
100 lux typically and the device has been optimized for use
with a 100kΩ output scaling resistor (REXT). The device and the
evaluation board will work from a 3V supply.
Evaluation Package
• Evaluation Board ISL76671EVAL1Z, populated with all
required components
• AN1741: “ISL76671 Low Power, <100 Lux Optimized,
Analog Output Ambient Light Sensor Evaluation Hardware
User Guide” (see Technical Documentation on the ISL76671
product information page)
Hardware Setup
The small ISL76671 evaluation board comprises the sensor
device itself and a 100kΩ resistor which sets the output
scaling for the sensor. The part was characterized with the
100kΩ resistor. Larger or smaller values can be used, however,
Intersil found that the 100kΩ value worked well under a variety
of conditions. Note that with larger scale setting resistors the
sensor is likely to prematurely saturate at relatively low light
levels. Please check Page 7 of the ISL76671 datasheet for a
description of the output scaling factor relative to incident
ambient light.
The jumpers and components on the printed circuit board
(PCB) are as shown in Table 1.
TABLE 1. JUMPERS, COMPONENTS ON PCB
JUMPER DESCRIPTION
JP1 REXT = 100kΩ(Default)
JP2 REXT = 47kΩ
JP3 REXT = 147kΩ
JP4 RLOAD = 10kΩ
(Optional, Do not populate)
JP5 RLOAD = 100kΩ
(Optional, Do not populate)
JP6 RLOAD = 1MΩ
(Optional, Do not populate)
C1 0.1µF
D1 Optional
L1 Optional
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas LLC 2012. All Rights Reserved.
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
March 14, 2012
AN1741.0
Application Note 1741
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Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is
cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
AN1741.0
March 14, 2012
FIGURE 1. ISL76671EVAL1Z EVALUATION BOARD SCHEMATIC
VCC
GND1
L1
BEAD
C1
0.1uF
R4
10k
R5
100k
JP4 JP5 JP6
TP1
VOUT
VCC
JP1 JP2 JP3
R1
100k
R2
47k
R3
147k
R6
1M
6
4
2
1
3
5
7
U1
ISL76671
GND2
D1
BAT42
VOUT
REXT
GND
VCC
NC1
NC2
TP
