QX844是一款由发光二极管和光电晶体管组成的光电耦合器。十六引脚封装（SSOP16）。 

The QX844 is a photoelectric coupler composed of light-emitting diode and phototransisto. It is packaged in a 16-pin package at SSOP16.

  DC-DC转换器 DC-DC converter 

  通讯设备 Communications equipment 

  可编程控制器 Programmable controller 

  信号传输 Signal transmission