Low-light challenges in a PFM digital pixel sensor: Leakage and quantization
This paper presents a comprehensive analysis and simulation of reset leakage currents and quantization errors in pulse frequency modulation (PFM) digital pixel sensors (DPS). The literature has reported these sensors for both visible and infrared applications with high dynamic range (HDR) imaging an...
| Autores: | , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/402115 |
| Acesso em linha: | http://hdl.handle.net/10261/402115 https://api.elsevier.com/content/abstract/scopus_id/105009707239 |
| Access Level: | acceso abierto |
| Palavra-chave: | CMOS image sensor (CIS) Digital pixel ROIC (DPROIC) Digital pixel sensor (DPS) Leakage Pulse frequency modulation (PFM) Readout integrated circuit (ROIC) |
| Resumo: | This paper presents a comprehensive analysis and simulation of reset leakage currents and quantization errors in pulse frequency modulation (PFM) digital pixel sensors (DPS). The literature has reported these sensors for both visible and infrared applications with high dynamic range (HDR) imaging and low-power requirements. The work investigates the benefits of using an NMOS reset switch in mitigating leakage currents, particularly in low-light conditions, where PMOS reset implementations often fail to sustain proper photocurrent integration. By characterizing leakage mechanisms, including subthreshold, gate-induced drain leakage, and reverse-bias junction currents, we derive their influence on photogenerated charge integration and propose methods to optimize pixel design for enhanced sensitivity. Furthermore, quantization error caused by residual charge and leakage is analyzed, highlighting their impact on dynamic range and performance. We validate the theoretical insight with simulation results from an advanced CMOS technology, demonstrating improved low-light performance and reduced error using the NMOS reset. These findings provide a framework for designing high-performance PFM pixels for future imaging applications. |
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