Tiny laser shrinks proximity detector size and power

Rohm RPR-0720 vcsel proximity detector

Built around a vcsel (vertical cavity surface-emitting laser), RPR-0720 measures only 2 x 1 x 0.55mm including its photodiodes and control IC.

Rohm RPR-0720 vcsel proximity detector block

The internal IC operates over 1.7 to 3.6V, drawing 16μA (typ for 50μs mode, 35μA max) when it is not driving the laser and 300μA (500μA max) when it is. Standby is at 700nA (5μA max).

It provides a controllable constant current sink for the vcsel, which has a separate power terminal and will work over 2.7 to 4.5V, allowing it to be connected directly to a Li-ion battery without needing its own regulator.

Rohm RPR-0720 vcsel proximity detector

Proximity detection range is 0 to 15mm (white surface) and can be as far as 50mm, and it will work over -30 to +85°C. Communication is via an I2C interface.

For development, evaluation board RPR-0720-EVK can be combined with  a custom software package.

“Going forward, Rohm will continue to develop sensing products combining original light receiving and emitting elements to further improve energy savings and convenience,” said the company.

Applications are foreseen detecting the attachment and detachment of wireless ear buds as well as in smart watches, gaming console controllers and VR headsets.

Find the RPR-0720 product page here

Source

      Guidantech
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