This part is a kind of semiconductor called 4N26M.

Function of this product has (4N25M - 4N37M) General Purpose 6-Pin Phototransistor Optocouplers.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

4NXXM, H11AXM General Purpose 6-Pin Phototransistor Optocouplers March 2007 4N25M, 4N26M, 4N27M, 4N28M, 4N35M, 4N36M, 4N37M, H11A1M, H11A2M, H11A3M, H11A4M, H11A5M General Purpose 6-Pin Phototransistor Optocouplers Features ■ UL recognized (File # E90700, Volume 2) ■ VDE recognized (File # 102497) tm Description The general purpose optocouplers consist of a gallium arsenide infrared emitting diode driving a silicon phototransistor in a 6-pin dual in-line package. – Add option V (e.g., 4N25VM) Applications ■ Power supply regulators ■ Digital logic inputs ■ Microprocessor inputs Functional Block Diagram 1 6 6 2 5 1 6 1 3 NC 4 6 PIN 1. ANODE 2. CATHODE 3. NO CONNECTION 4. EMITTER 5. COLLECTOR 6. BASE 1 ©2005 Fairchild Semiconductor Corporation [ ... ]

4N26M PDF Datasheet Download