A 3.36 µm-pitch SPAD photon-counting image sensor using clustered multi-cycle clocked recharging technique with intermediate most-significant-bit readout

This paper presents a photon-counting image sensor with $3.36 \mu \mathrm{m} -$pitch pixel front-end circuits and single-photon avalanche diodes (SPADs). A clustered multi-cycle clocked recharging technique with intermediate most-significant-bit readout achieves 120-dB high dynamic range (HDR) at 150fps imaging with $748 \times 448$ pixels, while reducing the pixel front-end circuit to a $3.36 \mu \mathrm{m}$ pitch. The power consumption is suppressed to 104 mW, even with 1.2 million incident photons per pixel. A prototype demonstrates HDR global-shutter photon-count imaging with motion artifact suppression and no analog readout noise.