Proving the Business Case for the Internet of Things

Vishay sensors improve detection for medical wearables

Steve Rogerson
November 7, 2017

To meet the need for reliable signal detection in wearable devices and medical and industrial applications, Pennsylvania component maker Vishay Intertechnology has introduced two high-speed silicon PIN photodiodes that deliver enhanced sensitivity for visible light.
Using infra-red radiation suppression filters and black packages for an improved signal-to-noise ratio, the VEMD5510C and VEMD5510CF provide fast switching times and low capacitance in compact top-view, surface-mount packages.
The devices are optimised for optical heart rate measurement in wearable devices such as fitness trackers and smart watches, as well as in medical biosensors connected to patient monitoring systems. In addition, they provide high-speed photo detection for flame detectors and ambient light sensing for display dimming or light adjustment functions.
The photodiodes come in 5 by 4mm packages with a 0.9mm profile to enable slim sensor designs.
Featuring a radiant-sensitive area measuring 7.5mm², the photodiodes offer sensitivity ranges from 440 to 700nm for the VEMD5510C and 440 to 620nm for the VEMD5510CF, with reverse light currents of 0.6 and 0.25µA, respectively. The devices' on-chip suppression filters eliminate disturbances from non-visible light, while their black packages block unwanted lateral illumination. This results in spectral sensitivity of less than 5% for wavelengths greater than 800nm for the VEMD5510C and greater than 700nm for the VEMD5510CF, closely matching that of the human eye.
The VEMD5510C and VEMD5510CF have a ±65° angle of half-sensitivity, an operating temperature of -40 to +100°C, and 550 and 540nm wavelengths of peak sensitivity, respectively. RoHS-compliant, halogen-free, and Vishay Green, the photodiodes provide a moisture sensitivity level of four in accordance with J-STD-020 for a floor life of 72 hours.
Samples and production quantities are available now, with lead times of eight weeks for large orders.
Vishay Intertechnology, a Fortune 1000 Company listed on the New York Stock Exchange, is one of the world's largest manufacturers of discrete semiconductors and passive electronic components. These components are used in virtually all types of electronic devices and equipment, in the industrial, computing, automotive, consumer, telecommunications, military, aerospace, power supplies and medical markets.