The RPI-221A is a reflective photosensor from Rohm Semiconductor. Similar to other sensors in its family, it integrates an infrared emitting diode (IRED) and a phototransistor into a single molded package. This allows it to detect objects by sensing the reflection of infrared light. It is designed for applications requiring reliable and compact object detection.

Applications

• Paper detection: Used in printers, fax machines, and copiers to detect the presence or absence of paper.
• Object sensing in automated machinery: Detecting parts or products on production lines.
• Position sensing: Determining the position of moving parts in equipment.
• End-of-travel detection: Identifying the end point in linear actuators or other moving mechanisms.
• Gaming devices: Object detection in toys and gaming controls.

Features

• Integrated IRED and phototransistor: Reduces component count and simplifies circuit design.
• Compact size: Facilitates use in space-constrained applications.
• High sensitivity: Provides reliable object detection even with low reflectivity surfaces.
• Fast response time: Enables high-speed object detection.
• Low current consumption: Suitable for battery-powered applications and energy-efficient designs.

Benefits

• Simplified system design: Integration simplifies the circuit and reduces development time.
• Reduced BOM cost: Fewer components translate to lower overall cost.
• Improved reliability: Robust design ensures consistent performance in various environments.
• Enhanced system efficiency: Low current consumption contributes to energy savings.
• Precise Object Detection: Accurate and dependable object detection for increased application performance.

Additional Details

The RPI-221A operates with a forward current (IF) of typically 20mA for the IRED. The collector-emitter voltage (VCEO) for the phototransistor is around 30V. It's designed for a spectral sensitivity in the infrared range, ensuring optimized performance with its integrated IRED. Its operating temperature range usually falls between -25°C to +85°C, making it versatile for diverse operational settings. The output signal is analog, dependent on the intensity of the reflected infrared light received by the phototransistor. External components, such as resistors, are typically needed to convert the current output from the phototransistor into a measurable voltage signal.