# A 1000 fps High-Dynamic-Range Global Shutter CMOS Image Sensor with Full Thermometer Code Current-Steering Ramp

## TL;DR

This paper introduces a high-speed, high-dynamic-range CMOS image sensor with a unique current-steering ramp design for improved performance.

## Contribution

The novel contribution is a 1000 fps global shutter CMOS image sensor with a full thermometer code current-steering ramp and 95 dB dynamic range.

## Key findings

- The sensor achieves 95 dB dynamic range with 620 ke- full well capacity.
- Pixel noise and non-linearity from parasitic capacitance are analyzed.
- A 12-bit thermometer code DAC is used for the ramp generator with high driving capability.

## Abstract

We present a 1024 × 512, 1000 fps, high-dynamic-range global shutter CMOS image sensor. The pixel is based on a voltage domain global shutter architecture, featuring a pitch of 24 μm × 24 μm. Both high-gain and low-gain signals can be captured within a single frame. The combined dynamic range is 95 dB, and the full well capacity is 620 ke-. In this paper, we analyze the pixel noise performance as well as the non-linearity and image lag that arise from parasitic capacitance in the pixel. The ramp generator is based on a 12-bit full thermometer code current-steering DAC with high driving capability. We discuss the design considerations for the ramp generator, particularly addressing the phenomenon of non-linear response. Finally, the comparator design and the column readout noise are analyzed.