H21B1, H21B2, H21B3

Photodarlington Optical Interrupter Switch

Product type IC(ON) (mA) min Test Conditions Output Aperture Width (mm)
H21B1 7.5 If=10mA, VCE = 1.5V Photodarlington 0.94
H21B2 14.0 If=10mA, VCE = 1.5V Photodarlington 0.94
H21B3 25.0 If=10mA, VCE = 1.5V Photodarlington 0.94


  • No Contact Sensing
  • 1mm Aperture
  • High IC(ON)
  • PCB mount
  • Darlington output
  • RoHS compliant


The H21BX products consist of a infrared light emitting diode coupled to an NPN silicon photodarlington packaged in a injection molded housing. The package is designed to optimize the mechanical resolution, coupling efficiency, ambient light rejection, and reliability. Inserting/removing an opaque material into the gap when the LED is operating, switches the darlington on/off.

Download the datasheet

Package Dimensions

  1. Dimensions for all drawings are in millimeters.
  2. Tolerance of +/- 0.25 on all non nominal dimensions unless otherwise specified