Sensor and analog IC maker ams AG has introduced new proximity sensing and proximity/ambient light-sensing modules, which enable android smartphone manufacturers to reduce the sensor aperture in the display's cover glass to its smallest diameter.
According to ams, an inability to overcome the effects of optical crosstalk have prevented Android phone manufacturers from reducing proximity-sensing apertures below 3.0 mm. The company says that by using its TMD2620 proximity sensor or the TMD2725, a combined proximity and ambient light sensor, phone manufacturers can reduce the aperture's size by as much as 50%, improving aesthetic appeal, especially in devices with a white or light-colored bezel. The TMD2620 and TMD2725 enable aperture size as small as 1.4 mm and 2.0 mm, respectively.
The optical module package design of the TMD2620 and TMD2725 allows the infra-red LED emitter and sensing photodiode to be placed just 1.0 mm apart. Lenses on top of the emitter and sensor, along with an optical barrier between them, help to minimize crosstalk caused by reflections from the surfaces of the cover glass. Offset adjustment registers eliminate the effect of any residual crosstalk from the module's proximity calculations. Automatic ambient light subtraction further enhances the accuracy of the device's proximity measurements. ams characterizes the range of the two new sensors—up to 100 mm—as comparable to laser-based solutions.
The TMD2620 and TMD2725 are in volume production now. Unit pricing in order quantities of 1,000 is 36 cents for the TMD2620, and 43 cents for the TMD2725.