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STMicroelectronics |
UVIS25
Digital UV Index sensor: 0 - 15 UV Index output range
Datasheet - preliminary data
LGA-10L
(2.5 x 2.5 x 0.76 mm)
Features
• 0 - 15 UV Index output range
• Resolution: UVI/16
• Active and power down modes
• Continuous reading at 1 Hz ODR / one shot
mode
• Interrupt functions: Data Ready and UVI
thresholds
• SPI and I²C interfaces
• Supply voltage: 1.7 to 3.6 V
• ECOPACK® lead-free compliant
Description
The UVIS25 is a digital UV Index sensor able to
provide an accurate measurement of the
Ultraviolet radiation index (UVI) from the sunlight.
It includes a sensing element and a mixed signal
ASIC to provide the UV Index data trough I2C and
SPI interfaces.
A dedicated technology has been developed to
achieve the best accuracy for UV Index
measurements.
The UVIS25 allows the measurement of the UV
Index, without the need of a dedicated algorithm
to calculate the UV Index and without specific
calibrations at customer manufacturing line.
The device can be configured to generate
interrupt events based on a threshold crossing or
when a new set of data is generated. The event is
available in a register as well as in a dedicated
pin.
The UVIS25 is available in a full-mold LGA
package (LGA). It is guaranteed to operate over a
temperature range extending from -20°C to
+85°C. The package is transparent to allow
external solar radiation to reach the sensing
element.
Applications
• UV Index measurements
• Wearable devices
• Smartphone and tablet
• Weather stations
Order code
UVIS25TR
Table 1. Device summary
Temperature range
[°C]
Package
-20 to +85
LGA-10L
Packing
Tape and reel
February 2015
DocID027323 Rev 1
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to
change without notice.
1/26
www.st.com
Contents
Contents
UVIS25
1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Sensor parameters and electrical specifications . . . . . . . . . . . . . . . . . . 6
2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 I2C interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Factory calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Digital interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 I²C serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1.1 I²C operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2 SPI bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2.1 SPI read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2.2 SPI write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.3 SPI read in 3-wires mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6 Register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7 Register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1 WHO_AM_I (0Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.2 CTRL_REG1 (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.3 CTRL_REG2 (21h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.4 CTRL_REG3 (22h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.5 INT_CFG (23h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.6 INT_SOURCE (24h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.7 THS_UV (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.8 STATUS_REG (27h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.9 UV_OUT_REG (28h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2/26 DocID027323 Rev 1
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