Document
Technical coantmesntAsGtill valid
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Features
D Ambient Light Sensing (ALS)
− Approximates Human Eye Response − Programmable Analog Gain and
Integration Time − 45,000,000:1 Dynamic Range − Operation to 60,000 lux in Sunlight − Very High Sensitivity — Ideally Suited for
Operation Behind Dark Glass − Package UV Rejection Filter
D Maskable Interrupt
− Programmable Upper and Lower Thresholds with Persistence Filter
D Wait Timer and Power Management
− Low Power 2.2 mA Sleep State with UserSelectable Sleep-After-Interrupt Mode
− 90 mA Wait State with Programmable Wait Time from 2.7 ms to > 8 seconds
D I2C Fast Mode Compatible Interface
− Data Rates up to 400 kbit/s − Input Voltage Levels Compatible with VDD
or 1.8-V Bus
D Register Set- and Pin-Compatible with the
TSL2x71 Series
D Small 2 mm y 2 mm Dual Flat No-Lead (FN)
Package
TSL2572 LIGHT-TO-DIGITAL CONVERTER
TAOS132 − MARCH 2012
PACKAGE FN DUAL FLAT NO-LEAD
(TOP VIEW)
VDD 1 SCL 2 GND 3
6 SDA 5 INT 4 NC
Not Actual Size
Applications
D Display Backlight Control D Keyboard Illumination Control D Solid State Lighting Control for Daylight
Harvesting
D Printer Paper Detection
End Products and Market Segments
D Mobile Handsets, Tablets, Laptops,
Monitors and TVs, Portable Media Players
D Medical and Industrial Instrumentation D White Goods D Toys D Industrial/Commercial Lighting D Digital Signage D Printers
Description
The TSL2572 device family provides ambient light sensing (ALS) that approximates human eye response to light intensity under a variety of lighting conditions and through a variety of attenuation materials. Accurate ALS measurements are the result of TAOS’ patented dual-diode technology and the UV rejection filter incorporated in the package. In addition, the operating range is extended to 60,000 lux in sunlight when the low-gain mode is used.
While useful for general purpose light sensing, the TSL2572 device is particularly useful for display management to provide optimum viewing in diverse lighting conditions while extending battery life. The TSL2572 device family is ideally suited for use in mobile handsets, TVs, tablets, monitors, and portable media players where the display backlight may account for 50% to 70% of the system power consumption.
The LUMENOLOGY r Company
r
Texas Advanced Optoelectronic Solutions Inc.
1001 Klein Road S Suite 300 S Plano, TX 75074 S (972r) 673-0759 www.taosinc.com
Copyright E 2012, TAOS Inc. 1
I2C Interface
valid
TSL2572 LIGHT-TO-DIGITAL CONVERTER
TAOS132 − MARCH 2012
Functional Block Diagram
VDD GND
Wait Control
CH0
CH0 ADC
CH0 Data
ALS Control
CH1 ADC
CH1 Data
CH1
Interrupt Upper Limit
Lower Limit
INT SCL SDA
Detailed Description
The TSL2572 light-to-digital device provides on-chip photodiodes, integrating amplifiers, ADCs, accumulators, clocks, buffers, comparators, a state machine, and an I2C interface. Each device combines a Channel 0 photodiode (CH0), which is responsive to both visible and infrared light, and a channel 1 photodiode (CH1), which is responsive primarily to infrared light. Two integrating ADCs simultaneously convert the amplified photodiode currents into a digital value providing up to 16 bits of resolution. Upon completion of the conversion cycle, the conversion result is transferred to the data registers. This digital output can be read by a microprocessor through which the illuminance (ambient light level) in lux is derived using an empirical formula to approximate the human eye response.
Communication to the device is accomplished through a fast (up to 400 kHz), two-wire I2C serial bus for easy connection to a microcontroller or embedded controller. The digital output of the device is inherently more immune to noise when compared to an analog interface.
The device provides a separate pin for level-style interrupts. When interrupts are enabled and a pre-set value is exceeded, the interrupt pin is asserted and remains asserted until cleared by the controlling firmware. The interrupt feature simplifies and improves system efficiency by eliminating the need to poll a sensor for a light intensity value. An interrupt is generated when the value of an ALS conversion exceeds either an upper or lower threshold. In addition, a programmable interrupt persistence feature allows the user to determine how many consecutive exceeded thresholds are necessary to trigger an interrupt.
coantmesntAsGtill
Technical
Copyright E 2012, TAOS Inc. 2
r www.taosinc.com
The LUMENOLOGY r Company r
Technical coantmesntAsGtill valid
TSL2572 LIGHT-TO-DIGITAL CONVERTER
Terminal Functions
TERMINAL
NAME NO.
GND 3
INT 5
NC 4
SCL 2
SDA
6
VDD
1
TYPE
O I I/O
DESCRIPTION
Power supply ground. All voltages are referenced to GND. Interrupt — open drain (active low). Do not connect. I2C serial clock input terminal — clock signal for I2C serial data. I2C serial data I/O terminal — serial data I/O for I2C . Supply voltage.
TAOS132 − MARCH 2012
Available Options
DEVICE
ADDRESS
TSL25721
0x39
.