A background light resistant TOF range finder with integrated PIN photodiode in 0.35μm CMOS

Within this work a single pixel Time-of-Flight (TOF) based range finder is presented. The sensor is fabricated in a 0.35 μm 1P4M CMOS process occupying an area of 45 × 60 μm2 at ~50% fill factor. It takes advantage of the integrated PIN photodiode, representing, to the best knowledge of the author, the first reported TOF device done in this technology with a PIN detector. The measurement results show a standard deviation of 1 cm for a total integration time of 2.2 ms and a received optical power of 10 nW. Furthermore, the maximal measured integration time per single phase step is slightly below 1 ms, being an improvement by the factor of 40 over the previous work using a similar approach. As proven with the measurements, the background light influence on the measured distance can be neglected even if the dc light is by the factor of 600 larger than the modulation signal.

[1]  Horst Zimmermann,et al.  High dynamic range background light suppression for a TOF distance measurement sensor in 180nm CMOS , 2011, 2011 IEEE SENSORS Proceedings.

[2]  A. Nemecek,et al.  Distance measurement sensor with PIN-photodiode and bridge circuit , 2006, IEEE Sensors Journal.

[3]  Horst Zimmermann,et al.  A 16$\, \times $16 Pixel Distance Sensor With In-Pixel Circuitry That Tolerates 150 klx of Ambient Light , 2010, IEEE Journal of Solid-State Circuits.

[4]  Matteo Perenzoni,et al.  A QVGA-range image sensor based on buried-channel demodulator pixels in 0.18μm CMOS with extended dynamic range , 2012, 2012 IEEE International Solid-State Circuits Conference.

[5]  Horst Zimmermann,et al.  A 33 × 25 µm2 low-power range finder , 2012, 2012 IEEE International Symposium on Circuits and Systems.

[6]  Matteo Perenzoni,et al.  An 80×60 range image sensor based on 10µm 50MHz lock-in pixels in 0.18µm CMOS , 2010, 2010 IEEE International Solid-State Circuits Conference - (ISSCC).