Paper

Charge Overflow Control of A 3.96-µm 124dB HDR-DPS for Triple and Single Quantization Dual-Channel Operation

2025 Jun

Authors Ken Miyauchi*, Hsin-Li Chen**, Toshiyuki Isozaki*, Hideki Owada*, Rimon Ikeno*, Kazuya Mori*, Masayuki Uno*, Hideyuki Fukuhara*, Hirofumi Abe*, Masato Nagamatsu*, Isao Takayanagi*, Chih-Hao Lin**, Wen-Chien Fu**, Shou-Gwo Wuu**,
Song Chen***, Ramakrishna Chilukuri***, Wei Gao***, Andrew P. Hammond***, Tsung-Hsun Tsai***, and Chiao Liu***

2025 International Image Sensor Workshop (IISW)
https://imagesensors.org/2025-international-image-sensor-workshop/

In this paper, a dual-channel triple-quantization digital-pixel-sensor (3Q-DPS) which simultaneously captures a 124 dB high dynamic range (HDR) visible-light image and a 60 dB dynamic range (DR) near-infrared (NIR) depth image in global shutter is described. The sensor architecture and basic operation have already been reported, and the charge overflow control technology of the shared floating diffusion (FD) 3Q-DPS will be presented in this paper. Specifically, asymmetric one-side buried overflow paths are developed to prevent charge mixing in FD and charge leakage to the drain. The design was studied with an analytical model and Technology Computer Aided Design (TCAD) simulation which is verified with measurements. With this overflow control, good photo-response linearity without charge mixing or charge loss is achieved in the dual-channel operation.