Rohm has developed a VCSEL-based proximity sensor for wearables such as earbuds and VR.
The Rohm RPR-0720 uses a VCSEL laser diode with higher directivity than LEDs as the light emitting element and a sensor IC for the light receiving element.
The compact size of 2.0mm × 1.0mm is achieved by optimizing the module structure using in-house chips, reducing area by approximately 78% compared to conventional products.
The wide input voltage range (2.7V to 4.5V) of the built-in VCSEL eliminates the need for a peripheral voltage booster circuit (i.e. consisting of a power supply IC, three capacitors, and one inductor) when using a Li-ion battery. This gives space savings that leads to smaller applications and increased battery capacity and makes it suitable not only for sensing attachment/detachment, but also for detecting various conditions in a wide range of applications.
Rohm also offers the RPR-0720-EVK evaluation board for the proximity sensor which is available in distribution at Digikey, Mouser and Farnell.