This part is a kind of semiconductor called H11F1.

Function of this product has PHOTO FET OPTOCOUPLERS.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

PHOTO FET OPTOCOUPLERS H11F1 H11F2 H11F3 PACKAGE SCHEMATIC ANODE 1 6 OUTPUT TERM. 6 1 6 CATHODE 2 5 1 3 4 OUTPUT TERM. 6 1 DESCRIPTION The H11F series consists of a Gallium-Aluminum-Arsenide IRED emitting diode coupled to a symmetrical bilateral silicon photodetector. The detector is electrically isolated from the input and performs like an ideal isolated FET designed for distortion-free control of low level AC and DC analog signals. The H11F series devices are mounted in dual in-line packages. FEATURES As a remote variable resistor • ≤ 100Ω to ≥ 300 MΩ • ≥ 99.9% linearity • ≤ 15 pF shunt capacitance • ≥ 100 GΩ I/O isolation resistance As an analog switch • Extremely low offset voltage • 60 Vpk-pk signal capability • No charge injection or latch-up [ ... ]

H11F1 PDF Datasheet Download