VEMD4 Silicon PIN Photodiodes Vishay VEMD4 Silicon PIN Photodiodes are high-speed and high-sensitivity PIN photodiodes. Vishay offers surface-mounted automotive grade silicon PIN photodiodes in the compact 0805 case size. The devices are housed in black packages with a low 0.7 mm profile, 0.15 mm lower than previous-generation devices. The opaque sidewalls of the photodiodes eliminate unwanted lateral illumination so as to increase the signal-to-noise ratio.