FL817 PDF Datasheet – Phototransistor, Photocoupler

A photocoupler, also known as an optocoupler or an optoisolator, is an electronic component or device used to transfer electrical signals or data between two isolated circuits using light as the medium of communication. The primary purpose of a photocoupler is to provide electrical isolation and noise immunity between input and output circuits. This isolation helps protect sensitive components, such as microcontrollers or sensors, from voltage spikes, noise, or potential hazards in the input circuit.

Part Number: FL817

Function: Phototransistor Detector

Package: DIP 4 Pin Type

Manufacturer: FANGJING

Images:FL817 pdf Phototransistor


The FL817 series of devices each consist of an infrared Emitting diodes, optically coupled to a phototransistor detector. They are packaged in a 4-pin DIP package and available in Wide-lead spacing and SMD option.



1. Current transfer ratio : (CTR:50%-600% at IF=5mA,VCE=5V)

2. High isolation voltage between input and output (Viso=5000V rms)

3. Creepage distance>7.62mm

4. Pb free and ROHS compliant

FL817 pinout datasheet



1. Programmable controllers

2. System appliances,measuring instruments

3. Telecommunication equipments

4. Home appliances,such as fan heaters,etc

FL817 PDF Datasheet