The OLF300ET is suitable for interfacing Transistor-Transistor Logic (TTL) to Low Power Schottky Transistor-Transistor Logic (LSTTL), TTL, or Complementary Metal Oxide Semiconductor (CMOS), as well as wide bandwidth analog applications. Each OLF300ET has an LED and an integrated photodiode transistor detector mounted and coupled in a custom 8-pin hermetic flatpack package, providing 1000 VDC of electrical isolation between the input and output. The integrated photodiode transistor improves the switching speed by orders of magnitude as compared to standard photo transistors by reducing the base-to-collector capacitance. The internal shield provides excellent common-mode immunity performance.