DESCRIPTION
The H21A1, H21A2 and H21A3 consist of a gallium arsenide infrared emitting diode coupled with a silicon phototransistor in a plastic housing. The packaging system is designed to optimize the mechanical resolution, coupling efficiency, ambient light rejection, cost and reliability. The gap in the housing provides a means of interrupting the signal with an opaque material, switching the
output from an “ON” to an “OFF” state.

FEATURES
• Opaque housing
• Low cost
• .035” apertures
• High IC(ON)