ISL29028A_14 Datasheet, PDF (1/16 Pages) Intersil Corporation – Low Power Ambient Light and Proximity Sensor with Intelligent Interrupt and Sleep Modes

Low Power Ambient Light and Proximity Sensor with
Intelligent Interrupt and Sleep Modes
ISL29028A
The ISL29028A is an integrated ambient and infrared light-to-
digital converter with a built-in IR LED driver 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
microcontroller utilization.
For ambient light sensor (ALS) data conversions, an ADC
converts photodiode current (with a light sensitivity range up to
2000 Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz
flicker noise caused by artificial light sources.
For proximity sensor (Prox) data conversions, the built-in driver
turns on an external 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 540μs
conversion time.
The ISL29028A provides low power operation of ALS and
proximity sensing with a typical 138μA normal operation current
(110μA for sensors and internal circuitry, ~28μA for external LED)
with 220mA current pulses for a net 100μs, repeating every
800ms (or under).
The ISL29028A uses both a hardware pin and software bits to
indicate an interrupt event has occurred. An ALS interrupt is
defined as a measurement which 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.
The ISL29028A 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 lead ODFN package.
Applications
• Display and Keypad Dimming Adjustment and Proximity
Sensing for:
- Mobile Devices: Smart Phone, PDA, GPS
- Computing Devices: Laptop PC, Netbook
- Consumer Devices: LCD-TV, Digital Picture Frame, Digital
Camera
• Industrial and Medical Light and Proximity Sensing
Features
• Works Under All Light Sources Including Sunlight
• Dual ADCs Measure ALS/Prox Concurrently
• Intelligent Interrupt Scheme Simplifies μC Code
• 0.5% Typical Nonlinearity
Ambient Light Sensing
• Simple Output Code Directly Proportional to lux
• 50Hz/60Hz Flicker Noise and IR Rejection
• Light Sensor Close to Human Eye Response
• Selectable 125/2000 Lux Range
Proximity Sensing
• Proximity Sensor with Broad IR Spectrum
- Can Use 850nm and 950nm External IR LEDs
• IR LED Driver with I²C Programmable Sink Currents
- Net 100μs Pulse with 110mA or 220mA Amplitudes
- Periodic Sleep Time up to 800ms Between Pulses
• Ambient IR Noise Cancellation (Including Sunlight)
Intelligent and Flexible Interrupts
• Independent ALS/Prox Interrupt Thresholds
• Adjustable Interrupt Persistency
- 1/4/8/16 Consecutive Triggers Required Before Interrupt
Ultra Low Power
• 138μA DC Typical Supply Current for ALS/Prox Sensing
- 110μA for Sensors and Internal Circuitry
- 28μA Typical Current for External IR LED (Assuming
220mA for 100μs Every 800ms)
• <1.0μA Supply Current When Powered Down
Easy to Use
• Set Registers; Wait for Interrupt
• I²C (SMBus Compatible) Output
• Temperature Compensated
• Tiny ODFN8 2.0x2.1x0.7 (mm) Package
Additional Features
• 1.7V to 3.63V Supply for I²C Interface
• 2.25V to 3.63V Sensor Power Supply
• Pb-Free (RoHS Compliant)
• I²C Address Selection Pin
January 29, 2014
1
FN7721.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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