High-Speed Image Sensor

A high-speed 512 x 512 CMOS image sensor with column-parallel cyclic ADC's and a global electronic shutter is developed. The fully differential cyclic ADC achieves the highest resolution of 12b in the 3500frames/s CMOS image sensor. The proposed pixel uses a charge amplifier in each pixel to enhance the sensitivity and sample-and-hold circuits for global electronic shuttering. The measured signal dynamic range is 60dB, and the sensitivity is as high as 19.9V/lx-s. The sensitivity is two times higher than that of the high-speed image sensor which claims high sensitivity.

Chip micrograph.	Equivalent circuit of high-sensitivity pixel.
Schematic of amplifier shared 2-stage cyclic ADC with noise canceller.	Sample image(@3500frames/s).

References

1. M. Furuta, T. Inoue, Y. Nishikawa, S. Kawahito,"A 3500fps High-speed CMOS Image Sensor with 12b Column-Parallel Cyclic A/D Converters", Proc. 2006 Sympo. on VLSI Circuit, pp.276-277, 2006
2. M. Furuta, Y. Nishikawa, T. Inoue, S. Kawahito,"A High-Speed, High-Sensitivity Digital CMOS Image Sensor With a Global Shutter and 12-bit Column-Parallel Cyclic A/D Converters", IEEE Journal of Solid-State Circuits, Vol.42, No.4, pp.-, 2007