INTERSIL ISL29044A

Low Power Ambient Light and Proximity Sensor with
Internal IR-LED and Digital Output
ISL29044A
Features
The ISL29044A is an integrated ambient and infrared
light-to-digital converter with a built-in IR LED and I2C Interface
(SMBus Compatible). This device uses two independent ADCs
for concurrently measuring ambient light and proximity in
parallel. The flexible interrupt scheme is designed for minimal
micro-controller utilization.
• Internal LED + Sensor = complete solution
For ambient light sensor (ALS) data conversions, an ADC
converts photodiode current (with a light sensitivity range up to
3200Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz
flicker noise caused by artificial light sources.
• Pb-Free (RoHS compliant)
For proximity sensor (Prox) data conversions, the built-in driver
turns on an internal infrared LED and the proximity sensor ADC
converts the reflected IR intensity to digital. This ADC rejects
ambient IR noise (such as sunlight) and has a 547μs
conversion time.
• Adjustable interrupt persistency
- 1/4/8/16 consecutive triggers required before interrupt
• Works under all light sources including sunlight
• Dual ADCs measure ALS/Prox concurrently
• <1.0μA Supply current when powered down
• Temperature compensated
Intelligent and Flexible Interrupts
• Independent ALS/Prox interrupt thresholds
Applications
• Display and keypad dimming adjustment and proximity
sensing for:
- Mobile devices: Smart phone, PDA, GPS
- Computing devices: Laptop PC, Netbook, Tablet PC
- Consumer devices: LCD-TV, digital picture frame, digital
camera
- Industrial and medical light and proximity sensing
The ISL29044A provides low power operation of ALS and
proximity sensing with a typical 133μA normal operation
current (108μA for sensors and internal circuitry, ~25μA for
LED) with 220mA current pulses for a net 100μs, repeating
every 800ms (or under).
The ISL29044A uses both a hardware pin and software bits to
indicate an interrupt event has occurred. An ALS interrupt is
defined as a measurement that is outside a set window. A
proximity interrupt is defined as a measurement over a
threshold limit. The user may also require that both ALS/Prox
interrupts occur at once, up to 16 times in a row before
activating the interrupt pin.
Related Literature
• See AN1436, “Proximity Sensors”
The ISL29044A is designed to operate from 2.25V to 3.63V
over the -40°C to +85°C ambient temperature range. It is
packaged in a clear, lead-free 8 Ld ODFN package.
V_LED
V_PULLUP
I2C SLAVE 0
5 LED- LED+ 4
6 IRDR GND 3
7 INT
SCL 2
8 SDA
VDD 1
ISL29044A C1
0.1µF
R2
RES1
R1
RES1
C3
0.1µF
R3
RES1
I2C MASTER
VDD
I2C SLAVE 1 I2C SLAVE_n
C2
SCL
SCL
1µF
SDA
SCL
SDA
INT
CONTROLLER
SDA
2
I2C-DIAGRAM I C-DIAGRAM
FIGURE 1. TYPICAL APPLICATION
April 19, 2013
FN8419.1
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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ISL29044A
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without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
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FN8419.1
April 19, 2013