A 1.22 E-Rms Temporal Random Noise, 110 Db High Dynamic Range, $2.988 \mu\mathrm{m}$ Pixelpitch 3-Stacked Digital Pixel Sensor With on-Chip Hdr Merger

This paper presents the world's smallest $2.988 \mu ~\mathrm{m}$ pixel pitch, 3-megapixel (Mp) 3-stacked digital pixel sensor (DPS) with a low temporal random noise (RN) of 1.22 e-rms and a high dynamic range (HDR) of 110 dB in global-shutter operation mode for various applications. To achieve the low RN and HDR performances, a pixel-parallel analog-to-digital converter (P-ADC) architecture with a narrow noise bandwidth (BW) and split photodiode (PD) structure with the signal chopping operation for LED flicker mitigation (LFM) are utilized for the developed DPS, respectively. Especially, a 3 -stacked structure has been adopted for the small form factor of DPS and enhancing the on-chip image signal processing capability.