Optocoupler Phototransistor Output DIP-8 6N135

The 6N135, 6N136, ICPL4502 and ICPL4503 devices
each consists of an infrared emitting diode, optically
coupled to a high speed photo detector transistor.
A separate connection for the photodiode bias and
output-transistor collector increases the speed by
several orders of magnitude over conventional
phototransistor couplers by reducing the
base-collector capacitance of the input transistor.