Now showing items 1-16 of 16

    • Icon

      A CMOS Digital SiPM With Focal-Plane Light-Spot Statistics for DOI Computation  [Article]

      Vornicu, Ion; Bandi, Franco; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2017)
      Silicon photomultipliers can be used to infer the depth-of-interaction (DOI) in scintillator crystals. DOI can help to improve the quality of the positron emission tomography images affected by the parallax error. This ...
    • Icon

      A CMOS Imager for Time-of-Flight and Photon Counting Based on Single Photon Avalanche Diodes and In-Pixel Time-to-Digital Converters  [Article]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Editura Academiei Române, 2014)
      The design of a CMOS image sensor based on single-photon avalanche-diode (SPAD) array with in-pixel time-to-digital converter (TDC) is presented. The architecture of the imager is thoroughly described with emphasis on the ...
    • Icon

      A SPAD-based 3D imager with in-pixel TDC for 145ps-accuracy ToF measurement  [Article]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (SPIE, 2015)
      The design and measurements of a CMOS 64 × 64 Single-Photon Avalanche-Diode (SPAD) array with in-pixel Time-to-Digital Converter (TDC) are presented. This paper thoroughly describes the imager at architectural and ...
    • Icon

      An Experimentally-Validated Verilog-A SPAD Model Extracted from TCAD Simulation  [Presentation]

      López Martínez, Juan Manuel; Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2018)
      Single-photon avalanche diodes (SPAD) are photodetectors with exceptional characteristics. This paper proposes a new approach to model them in Verilog-A HDL with the help of a powerful tool: TCAD simulation. Besides, to ...
    • Icon

      Arrayable Voltage-Controlled Ring-Oscillator for Direct Time-of-Flight Image Sensors  [Article]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2017)
      Direct time-of-flight (d-ToF) estimation with high frame rate requires the incorporation of a time-to-digital converter (TDC) at pixel level. A feasible approach to a compact implementation of the TDC is to use the multiple ...
    • Icon

      CMOS Vision Sensors: Embedding Computer Vision at Imaging Front-Ends  [Article]

      Rodríguez Vázquez, Ángel Benito; Fernández Berni, Jorge; Leñero Bardallo, Juan Antonio; Vornicu, Ion; Carmona Galán, Ricardo (IEEE, 2018)
      CMOS Image Sensors (CIS) are key for imaging technol-ogies. These chips are conceived for capturing opticalscenes focused on their surface, and for delivering elec-trical images, commonly in digital format. CISs may ...
    • Icon

      Compact Real-Time Inter-Frame Histogram Builder for 15-Bits High-Speed ToF-Imagers Based on Single-Photon Detection  [Article]

      Vornicu, Ion; Darie, Ángela; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2019)
      Time-of-flight (ToF) image sensors based on single-photon detection, i.e., SPADs, require some filtering of pixel readings. Accurate depth measurements are only possible if the jitter of the detector is mitigated. Moreover, ...
    • Icon

      Compensation of PVT Variations in ToF Imagers with In-Pixel TDC  [Article]

      Rodríguez Vázquez, Ángel Benito; Vornicu, Ion; Carmona Galán, Ricardo (MDPI, 2017)
      The design of a direct time-of-flight complementary metal-oxide-semiconductor (CMOS) image sensor (dToF-CIS) based on a single-photon avalanche-diode (SPAD) array with an in-pixel time-to-digital converter (TDC) must ...
    • Icon

      Design of a compact and low-power TDC for an array of SiPM's in 110nm CIS technology  [Presentation]

      Bandi, Franco; Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2017)
      Silicon photomultipliers (SiPMs) are meant to substitute photomultiplier tubes in high-energy physics detectors and nuclear medicine. This is because of their -to name a few interesting properties- compactness, lower bias ...
    • Icon

      In-pixel Voltage-Controlled Ring-Oscillator for Phase Interpolation in ToF Image Sensors  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (2016)
      The design and measurements of a CMOS pseudodifferential voltage-controlled ring-oscillator (VCRO) are presented. It is aimed to act as time interpolator for arrayable picosecond time-to-digital convertors (TDC). This ...
    • Icon

      Live demonstration: Photon counting and direct ToF camera prototype based on CMOS SPADs  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2017)
      This demonstrator reveals the performance and features of a single photon avalanche diode (SPAD) camera prototype. It is aimed to 2D/3D vision by photon counting and direct time-of-flight (d-ToF), respectively. The imager ...
    • Icon

      Low-Noise and High-Efficiency Near-IR SPADs in 110nm CIS Technology  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2019)
      Photon detection at longer wavelengths is much desired for LiDAR applications. Silicon photodiodes with deeper junctions and larger multiplication regions are in principle more sensitive to near-IR photons. This paper ...
    • Icon

      On the calibration of a SPAD-based 3D imager with in-pixel TDC using a time-gated technique  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2015)
      The optical characterization of a CMOS 64×64 single-photon avalanche-diode (SPAD) array with in-pixel 11b time-to-digital converter (TDC) is presented. The overall full-width half-maximum (FWHM) of the detector ensemble ...
    • Icon

      Photon Counting and Direct ToF Camera Prototype Based on CMOS SPADs  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2017)
      This paper presents a camera prototype for 2D/3D image capture in low illumination conditions based on single-photon avalanche-diode (SPAD) image sensor for direct time-offlight (d-ToF). The imager is a 64×64 array with ...
    • Icon

      Real-Time Inter-Frame Histogram Builder for SPAD Image Sensors  [Article]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2018)
      CMOS image sensors based on single-photon avalanche-diodes (SPAD) are suitable for 2D and 3D vision. Limited by uncorrelated noise and/or low illumination conditions, image capturing becomes nearly impossible in a single-shot ...
    • Icon

      Wide range 8ps incremental resolution time interval generator based on FPGA technology  [Presentation]

      Vornicu, Ion; Carmona Galán, Ricardo; Rodríguez Vázquez, Ángel Benito (Institute of Electrical and Electronics Engineers, 2014)
      Accurate generation of picosecond-resolution wide-range time intervals has become a necessity for the characterization of time-to-digital converters involved in time resolved imaging. This paper presents the design and ...