Cyrus Bamji

A 0.13 μm CMOS System-on-Chip for a 512 × 424 Time-of-Flight Image Sensor With Multi-Frequency Photo-Demodulation up to 130 MHz and 2 GS/s ADC

We introduce a 512 × 424 time-of-flight (TOF) depth image sensor designed in a TSMC 0.13 μm LP 1P5M CMOS process, suitable for use in Microsoft Kinect for XBOX ONE. The 10 μm × 10 μm pixel incorporates a TOF detector that operates using the quantum efficiency modulation (QEM) technique at high modulation frequencies of up to 130 MHz, achieves a modulation contrast of 67% at 50 MHz and a responsivity of 0.14 A/W at 860 nm. The TOF sensor includes a 2 GS/s 10 bit signal path, which is used for the high ADC bandwidth requirements of the system that requires many ADC conversions per frame. The chip also comprises a clock generation circuit featuring a programmable phase and frequency clock generator with 312.5-ps phase step resolution derived from a 1.6 GHz oscillator. An integrated shutter engine and a programmable digital micro-sequencer allows an extremely flexible multi-gain/multi-shutter and multi-frequency/multi-phase operation. All chip data is transferred using two 4-lane MIPI D-PHY interfaces with a total of 8 Gb/s input/output bandwidth. The reported experimental results demonstrate a wide depth range of operation (0.8-4.2 m), small accuracy error ( 1%), very low depth uncertainty ( 0.5% of actual distance), and very high dynamic range ( >64 dB).

7.6 A 512×424 CMOS 3D Time-of-Flight image sensor with multi-frequency photo-demodulation up to 130MHz and 2GS/s ADC

Interest in 3D depth cameras has been piqued by the release of the Kinect motion sensor for the Xbox 360 gaming console. This paper presents the pixel and 2GS/s signal paths in a state-of-the-art Time-of-Flight (ToF) sensor suitable for use in the latest Kinect sensor for Xbox One. ToF cameras determine the distance to objects by measuring the round trip travel time of an amplitude-modulated light from the source to the target and back to the camera at each pixel. ToF technology provides an accurate high pixel resolution, low motion blur, wide field of view (FoV), high dynamic range depth image as well as an ambient light invariant brightness image (active IR) that meets the highest quality requirements for 3D motion detection.