Vishay Intertechnology has released a new silicon PIN photodiode that brings a higher level of sensitivity in the visible/near infrared wavelength to biomedical applications such as heart rate and blood oxygen monitoring.
The new VEMD8082 features increased reverse light current, decreased diode capacitance, and faster rise and fall times compared to previous-generation solutions. Additionally, its small form factor of 4.8 by 2.5 by 0.5 mm suits it to integration into low profile devices such as smart watches.
The high sensitivity is particularly important in biomedical applications such as photoplethysmography (PPG), where the photodiode is used to detect changes in blood volumeand flow by measuring the amount of light absorbed or reflected by blood vessels. In such applications, precise measurements are crucial for diagnosing and monitoring conditions such as cardiovascular disease.
Specifications include a radiant sensitive area of 6.0 mm2 and an increase in reverse light current of 18 to 20 per cent, depending on wavelength. Decreased diode capacitance from 50 to 46 pF, plus faster rise times of 40 v 110 ns, allow for higher sampling rates.
