**5. Conclusions**

The current-input pixel-level ADC with a high SNR and wide DR is proposed for the readout circuit of the MWIR microbolometer array. In the proposed readout circuit, A/D conversion is efficiently performed during the integration, and a sufficient integration time and large charge-handling capacity is obtained. Using a synchronous two-stage A/D conversion, the characteristics of the power consumption, SNR, and DR are improved with high resolution. The proposed pixel-level ADC has a very simple structure and low power consumption. This enables the final readout circuit to be suitable for applications in portable infrared cameras.

**Author Contributions:** D.W. supervised the research. J.L. and D.W. proposed the idea and designed the circuit. J.L. performed the simulation and mask layout. J.L. and I.N. performed the experiment and analysis. J.L. and D.W. wrote the initial manuscript. D.W. and I.N. revised and finalized the paper. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Korea governmen<sup>t</sup> (MSIT), gran<sup>t</sup> number 2020R1F1A1052571.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** This work was supported by the National Research Foundation of Korea (NRF) gran<sup>t</sup> funded by the Korea governmen<sup>t</sup> (MSIT) (No. 2020R1F1A1052571). This work was supported by the Catholic University of Korea, Research Fund, 2019. The chip fabrication and EDA Tool were supported by the IC Design Education Center.

**Conflicts of Interest:** The authors declare no conflict of interest.
