STMicroelectronics has introduced a family of time-of-flight sensors that bring advanced 3D depth imaging to smartphones and other devices.
The first member of the family is the VD55H1 which maps three-dimensional surfaces by measuring the distance to over half a million points. Objects can be detected up to five meters from the sensor, and even further with patterned illumination.
The unit has a 672 by 804 back-side illuminated (BSI) pixel array.
VD55H1 addresses is suitable for augmented and virtual reality use cases including room mapping, gaming, and 3D avatars. In smartphones, the sensor enhances the performance of camera-system features including bokeh effect, multi-camera selection, and video segmentation. Face-authentication security is also improved with higher resolution and more accurate 3D images to protect phone unlocking, mobile payment, and any smart system involving secure transactions and access control. In robotics, the VD55H1 provides high-fidelity 3D scene mapping for all target distances.
The VD55H1 operates with a modulation frequency of 200MHz with more than 85 percent demodulation contrast at 940nm light wavelength. This reduces the depth noise by a factor of two over sensors that operate around 100MHz. Depth accuracy is better than 1 percent and typical precision is 0.1 percent of distance.
Other features include a short capture sequence that supports a frame rate up to 120 fps and improves motion-blur robustness. In addition, advanced clock and phase management including spread spectrum clock generator (SSCG) provides multi-device interference mitigation and optimized electromagnetic compatibility.
The power consumption can be reduced to less than 100mW in some streaming modes.
Indirect time-of-flight (iToF) sensors, such as VD55H1, calculate the distance to objects by measuring the phase shift between the reflected signal and the emitted signal. This is a complementary technique to direct time of flight (dToF) sensors, which measure the time for transmitted signals to be reflected back to the sensor.
VD55H1’s pixel architecture and fabrication process makes use of in-house 40nm stacked wafer technology.
The sensor is available for customer sampling with volume production scheduled for 2H22. A reference design and complete software package are available to help accelerate sensor evaluation and project development.
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