New tiny photodiode

Louise Davis

Vishay broadens its optoelectronics portfolio with the introduction of a new high speed silicon PIN photodiode with enhanced sensitivity for visible light. Featuring a rectangular 4.8mm by 2.5mm top-view, surface-mount package with a low 0.48mm profile — 0.37mm lower than that of competing solutions — the Vishay Semiconductors VEMD8080 offers fast switching times and low capacitance of 47pF for precise signal detection in wearable devices and medical applications.

With a radiant-sensitive area measuring 4.5mm² — and high radiant sensitivity with a reverse light current of 28µA and dark current of 0.2nA — the device utilises Vishay's proven wafer technology to detect visible and near-infrared radiation over a wide spectrum range from 350nm to 1100nm. For green LEDs, the VEMD8080's sensitivity represents a 30% improvement over the standard technology in previous-generation solutions.

When used with green LEDs, such as Vishay's VLMTG1400, the photodiode's small size and high sensitivity enable slim sensor designs for optical heart rate detection in wearable devices such as fitness trackers and smartwatches. In these devices, the VEMD8080's rectangular shape allows several light emitting diodes to be placed close to the radiant sensitive area to maximise the signal. When combined with 660nm and 940nm dual colour emitting diodes, the photodiode is ideal for SpO2 measurement in medical monitors.

The VEMD8080 features a ± 65° angle of half-sensitivity, operating temperature range of -40°C to +85°C, and 950nm wavelength of peak sensitivity. RoHS-compliant, halogen-free, and Vishay Green, the photodiode provides a moisture sensitivity level (MSL) of 4 in accordance with J-STD-020 for a floor life of 72 hours.


 

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