Recently, Vishay announced the launch of a new visible light sensitivity enhanced high-speed silicon PIN photodiode, expanding its photodiode product portfolio. The Vishay Semiconductors VEMD2704 features a compact 2.0 mm x 1.8 mm x 0.6 mm top-view surface-mount package. Its transparent epoxy resin achieves industry-leading sensitivity, with a fast switching time of 70 ns and a low capacitance of 17.6 pF, making it suitable for precise signal detection in wearable devices.
The recently released device has a photosensitive area of 1.51 mm², offering high light sensitivity (reverse photocurrent of 1.17 µA and dark current of 0.03 nA). It can detect visible light and near-infrared radiation across a wide spectral range of 350 nm to 1100 nm. The photodiode is ideal for wearable devices such as fitness trackers and smartwatches, enabling optical heart rate detection with green LEDs and pulse oximetry with red LEDs.
Compared to the previous generation solution, the VEMD2704 is smaller in size, making it easier to integrate into compact products like earbuds. Optical systems can incorporate multiple photodiodes for more precise signal detection, while also enhancing the flexibility of sensor layouts. Additionally, the device is more cost-effective than its predecessor, making it an ideal choice for cost-sensitive devices like smart bands.
The VEMD2704 has a half-intensity angle of ±67°, an operating temperature range of -40 °C to +85 °C, and a peak sensitivity wavelength of 940 nm. The photodiode complies with RoHS and Vishay's green standards, is halogen-free, and has a moisture sensitivity level (MSL) of 3 according to the J-STD-020 standard, allowing for 168 hours of floor life in a workshop environment.
