Reflective Sensor for Medical Applications

The sensor measures just 0.300 x 0.160, with a PC board-mounted profile of just 0.114. It incorporates a lensed IR LED and phototransistor elements to collimate the light beam for enhanced resolution at a detection range from 0.4 (10mm) to 1.0 (25.4mm). The device is being used in tube-in-place and tube proximity hospital infusion pumps, with encoders for volumetric measurement in transfusion pumps, and as carousel/bin sensors for medicine dispensing equipment.

The OPB733TR sensor consists of an IR LED with typical peak emission wavelength of 890nm, mounted alongside a NPN silicon phototransistor, which responds to light reflected by the object being sensed. The phototransistor output on-state collector current is 0.1mA (100um) at 1/2 [12.7mm] distance from the target and a 20mA forward current and VCE of 5V. Rise and fall time for the phototransistor signal is typically 15uS. The surface mount package is reflow solder compatible to 260degC.