A 3.36-μm-Pitch SPAD Photon-Counting Image Sensor Using a Clustered Multi-Cycle Clocked Recharging Technique With an Intermediate Most-Significant-Bit Readout

A photon-counting image sensor with 3.36- <tex-math notation="LaTeX">μ</tex-math> m-pitch-pixel front-end (PFE) circuits and single-photon avalanche diodes is presented here. A clustered multi-cycle clocked recharging technique with an intermediate most-significant-bit readout is employed to achieve a 120-dB high dynamic range (HDR) at 150-frames/s imaging with 748 <tex-math notation="LaTeX">×</tex-math> 448 pixels while reducing the PFE circuit pitch to 3.36 <tex-math notation="LaTeX">μ</tex-math> m. The power consumption of the sensor is reduced to 104 mW, even with 1.2 million incident photons per pixel. A prototype is utilized to demonstrate the HDR global-shutter photon-count imaging with motion artifact suppression and no analog readout noise.