Onsemi QRE1113GR Reflective Object Sensor: Datasheet Overview and Practical Applications
The Onsemi QRE1113GR is a compact, high-performance reflective object sensor that integrates an infrared emitting diode (IRED) and a phototransistor in a single surface-mount package. This device is engineered to detect the presence or absence of objects by measuring the amount of infrared light reflected from a surface. Its design is optimized for applications requiring non-contact sensing, such as position encoding, edge detection, and object counting in consumer electronics, industrial systems, and automotive modules.
A key feature of the QRE1113GR is its high sensitivity and fast response time, allowing it to detect objects with high precision even at moderate speeds. The sensor operates effectively over a typical sensing distance of a few millimeters, making it ideal for close-proximity detection. The built-in IRED emits light at a wavelength of 940 nm, which is minimally affected by ambient visible light, reducing the risk of false triggering.
The electrical characteristics outlined in the datasheet highlight a low forward voltage drop for the emitter (typically 1.25V at 20mA) and a phototransistor collector current that varies proportionally with reflected IR intensity. This linear response enables analog distance estimation in addition to digital object detection. A common application circuit includes a current-limiting resistor for the emitter and a pull-up resistor for the phototransistor output, forming a voltage divider that produces a measurable signal.
Application notes emphasize the importance of calibration for specific reflective surfaces. Factors such as object color, surface texture, and environmental lighting conditions can significantly affect performance. For instance, highly reflective surfaces may saturate the phototransistor, while dark materials absorb more IR light, reducing signal strength. To mitigate ambient light interference, modulating the emitter signal and using synchronous detection is recommended in noisy environments.
In practice, the QRE1113GR is widely used in printer paper-end detection, motor encoder disk tracking, and robotic obstacle avoidance systems. Its small form factor (SMD Gull Wing package) and reliability under varying temperatures make it suitable for automated assembly and harsh operating conditions.
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ICGOOODFIND: The Onsemi QRE1113GR offers a cost-effective and reliable solution for reflective object sensing, combining integrated IR emission and detection in a single package. Its analog output provides flexibility for both presence sensing and distance measurement, though optimal performance requires careful calibration against target surface properties.
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Keywords: Reflective Object Sensor, Infrared Emitter, Phototransistor, Proximity Detection, Analog Output
