OSRAM Opto Semiconductors Introduces Proximity Sensors With Optical Touch Switch in SMT Package

OSRAM Opto Semiconductors’ two new SMT proximity sensors (SFH7740 and SFH7741) use distance measurements to detect a mobile device’s operating status without physical contact to the sensor itself. This technology allows for the automatic shut-off of displays and keypads when no longer needed, improving performance and efficiency of products such as cell phones and digital cameras. The proximity sensors can also be used to adjust the volume of the device’s speakers.

The SFH7740 proximity sensor with optical touch switch measures just 3.7 x 3.7 x 1.0 mm and reacts to distances between 0.5 and 4.0 mm. These compact dimensions allow it to be unobtrusively integrated into unusual designs, such as extremely low-profile devices. For example, it is small enough to fit in slider phones where it can detect the position of the slider that reveals or hides the keypad. Depending on whether the slider is closed or open, the SFH7740 switches the display lighting off or on. The OSRAM sensor is an ideal alternative to Hall sensors as it is insensitive to electromagnetic interference and does not produce any electromagnetic interference itself.

OSRAM’s other new proximity sensor – model number SFH7741 – reacts at a typical working distance of 20mm and is suitable for a wide range of applications.