SPAD-Based Line Sensor IC for Chemiluminescence Assays in Microfluidic Channels

ABSTRACT
This paper introduces a novel microchip architecture for a single-photon avalanche diode (SPAD)-based line sensor tailored for in-vitro diagnostic chemiluminescence assays in microfluidic channels. Our work describes the specific design and optimization aspects of SPADs, including optical active area maximization and dark count rate (DCR) reduction while maintaining a high photon detection probability.
The chip architecture features a high-density SPAD sensor array (192 rows) with hot pixel calibration for improved SNR. It supports row-wise pulse counting, adjustable measurement intervals, on-chip SRAM for data storage, ALU with memory-saving bfloat16 encoding, and interfacing via I2C and QSPI.