Performance Characterization and Tuning of a Charge-Splitting High Dynamic Range 4-Tap CMOS Image Sensor

Area of Science:

• Image Sensors
• Computational Imaging
• Semiconductor Devices

Background:

• High dynamic range (HDR) imaging is crucial for automotive and surveillance, facing challenges from motion artifacts and LED flicker.
• Charge-splitting HDR imaging with multi-tap CMOS image sensors (CIS) offers a solution by mitigating these issues and enabling programmable dynamic range extension.

Purpose of the Study:

• To develop a model for charge-splitting pixel performance.
• To experimentally characterize and optimize a 4-tap CIS for enhanced HDR imaging capabilities.

Main Methods:

• Development of a performance model for charge-splitting pixels.
• Experimental characterization and tuning of a 4-tap CIS.
• Evaluation of dynamic range (DR) and signal-to-noise ratio (SNR) performance.

Main Results:

• A single-exposure dynamic range (DR) of 126 dB was achieved for the 4-tap CIS.
• This represents a 16 dB improvement over previous benchmarks (110 dB).
• A high signal-to-noise ratio (SNR) was maintained, with a minimum transition SNR above 30 dB.

Conclusions:

• The developed model accurately describes charge-splitting pixel performance.
• Optimized 4-tap CIS technology significantly enhances single-exposure HDR imaging.
• This advancement holds great potential for demanding applications like automotive and surveillance cameras.