The IA1101 is a multi-function, medium-range (0-40cm) active proximity detector. Because it operates on an absolute reflectance threshold principle it avoids ambiguity of motion based proximity systems both active and passive. To achieve maximum performance high optical isolation (less than 10E-6 coupling) is required between two millimeter-sized light ports—one for the transmit LED and the other for the IA1101. For reduced-range applications (~10cm) existing holes with high optical loss in a product case may be reused as optical ports, such as display windows, illumination light piping, camera windows, infrared receiver windows, or headphone/microphone holes. The detector even works without a dedicated window if a semi-opaque plastic case is used.

The IA1101 consists of a patented, high-EMI immunity, differential photodiode and a signal processing IC that includes an LED driver and a high-gain optical receiver. These provide both optical proximity detection and ambient light sensing. Proximity detection is based on measuring the reflected light from a strobed, optically isolated LED.

The standard package for the IA1101 is an SOIC-8. Custom packaging, including DFN 3x3, is available upon request.