A 326,000 fps 640 x 480 Resolution Continuous-Mode Ultra-High-Speed Global Shutter CMOS BSI Imager

Abstract

This paper describes an ultra-high-speed monolithic global shutter CMOS image sensor capable of continuous motion capture at 326,000 fps with a resolution of 640 × 480 pixels. The performance is enabled by a novel combination of pixel technology and circuit techniques. The highly sensitive BSI pixel with a 52 μm pitch employs a fully depleted substrate to facilitate rapid photocarrier transport. In-pixel voltage mode storage enables pipelined readout, while in-pixel analog CDS provides low noise with minimal impact on readout speed. The sensor achieves an equivalent row time of 6.4 ns through separate top and bottom readout together with multiple parallel ADCs per column. Independent row drivers on both the left and right sides ensure the global shutter accuracy needed for the minimum exposure time of 59 ns. The dynamic range is enhanced by on-chip reduction in FPN and by PTC-based data compression. The sensor delivers a throughput of 100 Gpix/sec, transferred off chip via 128 CML channels operating at 6.6 Gbps each. The device is fabricated using a 130 nm monolithic CIS process with BSI postprocessing and is in series production.