VORNICU , Ion

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 contemplate system-level aspects that affect its overall performance. This paper provides a detailed analysis of the impact of...

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 in-pixel TDC for high frame rate acquisition. Circuit design techniques are combined to ensure successful 3D image capturing...

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 characterization of the TDCs array. It is targeted for 3D image reconstruction. Several techniques as fast...

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 measurement of a time interval generator based on FPGA technology. Although it can be employed in different automatic test...

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 circuit level with particular emphasis on the characterization of the SPAD-detector ensemble. It is aimed to 2D imaging and 3D image...

The design and simulation of a CMOS 8 × 8 single photon avalanche diode (SPAD) array is presented. The chip has been fabricated in a 0.18μm standard CMOS technology and implements a double functionality: measuring the Time-of-Flight with the help of a pulsed light source; or computing focal-plane statistics in biomedical imaging applications...

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 phases of a voltage-controlled ring-oscillator (VCRO) for the finest bits. The VCRO becomes central in determining the...

Fotomultiplicador digital de combinación OR de pulsos.El fotomultiplicador comprende un conjunto de macroceldas, cada una de ellas comprendiendo al menos dos microceldas (1), estando cada una conectada a un nudo de salida (7) siguiendo un esquema OR y log

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 SPAD plus TDC is 690ps. The sensor has been fabricated in a 0.18μm standard CMOS technology which features an average...

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 presents the complete electro-optical characterization of a P-well/ Deep N-well singlephoton avalanche diodes integrated in...

The design and characterization of a CMOS 64×64 single-photon avalanche-diode (SPAD) array with in-pixel 11b time-to-digital converter (TDC) is presented. It is targeted for time-resolved imaging, in particular 3D imaging. The achieved pixel pitch is 64μm with a fill factor of 3.5%. The chip was fabricated in a 0.18μm standard CMOS technology...

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 exposure time. Moreover, the depth accuracy is affected by jitter. Therefore, many frames need to be taken to...

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 is built on a standard CMOS technology without any opto flavor or high voltage option. The camera module consists of a 64×64...

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 design is incorporated into a 64×64 array of TDCs for time-of-flight (ToF) measurement. It has been fabricated in a 0.18μm...

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 voltage, tolerance to magnetic fields and finer spatial resolution. SiPMs can also be built in CMOS technology. This allows...

This paper presents a FPGA implementation of a novel depth map estimation algorithm for direct time-of-flight CMOS image sensors (dToF-CISs) based on single-photon avalanche-diodes (SPADs). Conventional ToF computation algorithms rely on complete ToF histograms. The next generation of high speed dToF-CIS is expected to have wide dynamic range...

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 paper contemplates the computation of DOI based on the standard deviation of the light distribution. The simulations have been...

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, the time stamp needs to be effectively separated from uncorrelated noise, such as dark counts and background illumination....