Opto-Electronics


UV-A light detection for wearable and mobile devices

27 October 2021 Opto-Electronics

Monitoring vital signs such as pulse or oxygen saturation in the blood via smartphones and smartwatches has been available for several years. The corresponding UV channel of the TSL2585 from ams Osram detects the amount of UV-A radiation in natural sunlight, enabling the user to be warned of excessive UV-A radiation. Thanks to its extremely compact dimensions, the sensor is ideally suited for space-constrained wearable and other mobile applications.

While the UV-C portion of sunlight is blocked by the earth’s atmosphere, UV-A and UV-B radiation reaches the Earth’s surface. UV-B radiation penetrates only the upper layers of the skin and is responsible for sunburn. UV-A radiation, which accounts for around 90% of the UV component that reaches the Earth’s surface, penetrates much deeper into the lower layers of the skin and can, in some cases, have significant health consequences – from weakening the connective tissue to faster ageing of the skin and a higher probability to develop skin cancer. With the help of this new ambient light sensor, smartwatch users can now be warned as soon as the UV-A dose in their environment becomes too high.

The sensor utilises advanced interference filters which are precisely deposited on each photodiode pixel to create a 315-400 nm UV-A channel, a human-eye response photopic channel and an IR channel. These provide essential information for indoor/outdoor identification, UV index calculation and ambient illuminance detection. Additionally, the TSL2585’s unique edge-located photodiode placement supports very narrow µBezel design.

The TSL2585 has integrated light flicker detection on-chip and is equipped with three modulators with up to 14 kHz sampling rate. By providing the illuminance information and ambient light flicker information to the phone camera, it supports fast auto exposure and removal of banding effects caused by flicker from environmental lighting.

The compact dimensions of the extremely flat package – only 2,0 mm x 1,0 mm x 0,35 mm – allow for space-saving system designs to help manufacturers of extremely compact devices. The sensor can be operated with a voltage of 1,8 V and consumes only 0,7 µA when inactive.


Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Qualcomm AI stack: a unified AI software solution
Future Electronics Computer/Embedded Technology
Qualcomm has bundled all its AI software offerings into a single package called the Qualcomm AI Stack which will assist developers in deploying AI applications.

Read more...
Hamamatsu Photonics boosts production capacity
Hamamatsu Photonics UK Opto-Electronics
Hamamatsu Photonics increases its current production capacity almost two-fold to help with expanding sales after completion of a new factory complex.

Read more...
Vicor launches new automotive e-book on electrification
Future Electronics News
The downloadable e-book from Vicor shares insights into new power conversion trends and technologies to support vehicle electrification.

Read more...
New compact SMT chokes for low-voltage applications
Future Electronics Passive Components
TDK has released three new B8272 series of compact EPCOS SMT common-mode chokes specially developed for DC/DC converters and low-voltage applications.

Read more...
Digital ambient light sensor
EBV Electrolink Opto-Electronics
The device is a highly sensitive light-to-digital converter that transforms light intensity into a digital signal output through an I2C digital interface.

Read more...
STMicroelectronics’ new chip boosts energy efficiency
Future Electronics Power Electronics / Power Management
The new power-supply controller chip combines with ST’s MasterGaN technology in a laptop/smartphone charger design with energy recovery.

Read more...
ST’s new ToF sensor has double the range of existing modules
EBV Electrolink Opto-Electronics
The new sensor combines revolutionary metasurface lens technology with a more powerful and efficient laser and improved on-chip signal processing.

Read more...
Compact planar scanner with air bearing
Horne Technologies Opto-Electronics
PIglide positioning systems are ideally suited for high-precision applications such as inspection systems, laser marking, microscopy or scanning.

Read more...
Green laser diode for industrial applications
Future Electronics Opto-Electronics
ams OSRAM has introduced a green laser diode which is a brighter, more reliable and cost-competitive replacement for red lasers in applications such as levelling, scanning, biosciences and dot projection. ...

Read more...
Industrial MCU with gigabit time-sensitive networking
Future Electronics DSP, Micros & Memory
Time-sensitive networking solution by NXP bridges communication gaps in industrial IoT.

Read more...