PMD and Infineon Present Improved ToF Sensors

Infineon and pmd unveil their latest 3D image sensor chip of the REAL3 family. Compared to the previous version, the optical sensitivity as well as the power consumption of the new 3D sensors has been improved and the built-in electronics take up little space. The chips make it possible for cell phones to operate mini-camera systems that can measure 3D depth data.

The optical pixel sensitivity of the new 3D image sensors is now double that of the previous version. This means that their measurement quality is just as good, while at the same time working with only half of the emitted light output and the camera’s system power consumption is almost halved. The improved optical pixel sensitivity is the result of applying one microlens to each of the pixels of the 3D image sensor chip.

The new 3D image sensor chips were specifically designed for mobile devices, where most applications only need a resolution of 38,000 pixels. The previous 100,000-pixel matrix was accordingly scaled down, and other functional blocks, such as the analog/digital converter for the chip area and performance range were optimized. Thus, the system cost is lower: the sensor chip area is almost halved, and, because of the lower resolution, smaller and less expensive optical lenses can be used.

The three new REAL3 3D image sensors differ in their resolutions: the IRS1125C works with 352 x 288 pixels, the IRS1645C with 224 x 172 pixels and the IRS1615C with 160 x 120 pixels. In this respect, the IRS1645C and IRS1615C are produced on half the chip area of the IRS1125C.

Google’s “Project Tango” using Infineon's IRS1645C 3D image sensor chip. The complete 3D camera for Google “Tango” – consisting of IRS1645C and an active infrared laser illumination – is housed in an area of approximately 10 mm x 20 mm. With a range up to 4 meters (13 feet), a measuring accuracy of 1% of the distance and a frame rate of 5 fps, the 3D camera subsystem consumes less than 300 mW in active mode.

The IRS1125C will be available in volume in Q1 2016. The start of production for the smaller IRS1645C and IRS1615C is planned for Q2 2016. All three types are exclusively delivered as a bare die to allow maximum design flexibility while minimizing system costs.