Image Sensors at CICC

CICC turns into a virtual conference this year due to coronavirus pandemy. Historically, there is not that many image sensor papers presented there. However, this year there are two covering quite hot topics:

A 368 × 184 Optical Under-Display Fingerprint Sensor With Global Shutter and High-Dynamic-Range Operation

Chih-Wen Lu, Ping-Hung Yin (CTO of TYRAFOS Technologies Co., LTD ), Ping-Hung Yin, Jia-Shyang Wang, Keng-Li Chang, Fu-Kuo Lin, Chia-Jung Chang, and Gen-Chiuan Bai from National Tsing Hua University and TYRAFOS Technologies Co., LTD

This study proposes a 368 × 184 optical under-display fingerprint sensor. The prototype sensor features low noise, low-power consumption, fast response time, and a smaller signal processing circuit area. A dynamic range of 120 dB is achieved with 8-segment auto exposure and dark level adjustment with programmable gain control. The sensor has a chip size of 9.74 mm × 4.6 mm, a resolution of 1154 dpi, and a sensing area of 73%.

Design and Optimization of Low Power and Low Light Sensors

Christian Enz, Assim Boukhayma, Antonino Caizzone, and Raffaele Capoccia from EPFL ICLAB

This paper shows that many low-light applications share the same readout architecture. It explains how the readout circuit can be optimized for reaching a minimum input-referred noise without penalty on the power consumption. The design methodology is then illustrated by three applications, including a 0.5 electrons rms CMOS VGA imager, a 2.6uW PPG sensor and a 10uW 1D time-of-flight distance ranging device.