A 3.36-<i>μ</i>m-Pitch SPAD Photon-Counting Image Sensor Using a Clustered Multi-Cycle Clocked Recharging Technique With an Intermediate Most-Significant-Bit Readout
Takafumi Takatsuka, Jun Ogi, Y. Ikeda, Kazuki Hizu, Yutaka Inaoka, Shunsuke Sakama, Iori Watanabe, Tatsuya Ishikawa, Shohei Shimada, J. Suzuki, Hidenori Maeda, K. Toshima, Yusuke Nonaka, Akifumi Yamamura, Hideki Ozawa, Fumihiko Koga, Yusuke Oike
Abstract
A photon-counting image sensor with 3.36- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 448 pixels while reducing the PFE circuit pitch to 3.36 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> . 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.