Higher Quality Images For A Visiblelight Cmos Sensor By Suppressing Spatial Rowwise Noise With An Outputcapacitorless Internal Lowdropout Regulator

• doi: 10.1109/ISCAS45731.2020.9181141
• title: Higher Quality Images for a Visible-Light CMOS Sensor by Suppressing Spatial Row-Wise Noise with an Output-Capacitor-Less, Internal Low-Dropout Regulator
• publisher: IEEE
• isbn: 978-1-7281-3320-1
• issn: 2158-1525
• rank: 2657
• access_type: LOCKED
• content_type: Conferences
• abstract: Image quality of visible-light CMOS sensors normally suffers from fixed-pattern noise. Spatial row-wise noise in an image particularly is caused by pixel array power supply coupling. Common noise injection from a fluctuating power supply during pixel readout causes horizontal stripe noise because all signals in a row are affected by the noise simultaneously. By integrating an output capacitor-less low-dropout (LDO) regulator on chip to directly supply a regulated power to the imager pixel array exclusively, it is possible to reduce fixed-pattern row-wise noise considerably so that the row-stripe noise becomes invisible entirely. The LDO circuit uses internal inherent pixel array parasitic capacitances along with an integrated capacitor multiplier circuit to eliminate the need for an off-chip capacitor and thus isolates the pixel array from the external board components such as bond-wire, pad, and board traces. The LDO was designed and fabricated in 0.13 μm − 2P4M CMOS image sensor process and was implemented within a five-megapixel visible-light CMOS imager to prove the functionality and performance. Experimental data are included and shown that the row-wise noise is reduced by more than factor of five, making it negligible (and invisible) compare to the temporal pixel noise.
• article_number: 9181141
• pdf_url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9181141
• html_url: https://ieeexplore.ieee.org/document/9181141/
• abstract_url: https://ieeexplore.ieee.org/document/9181141/
• publication_title: 2020 IEEE International Symposium on Circuits and Systems (ISCAS)
• conference_location: Seville, Spain
• conference_dates: 12-14 Oct 2020
• publication_number: 9179985
• is_number: 9180369
• publication_year: 2020
• publication_date: 12-14 Oct 2020
• start_page: 1
• end_page: 4
• citing_paper_count: 3
• citing_patent_count: 0
• download_count: 831
• insert_date: 20200928
• index_terms:
  • ieee_terms:
    • Regulators
    • Capacitors
    • Capacitance
    • System-on-chip
    • CMOS image sensors
    • Layout
    • Logic gates
  • author_terms:
    • Low-Noise CMOS Imager
    • Output Capacitor-less Low-Dropout Regulator
    • Fixed-Pattern Noise
  • dynamic_index_terms:
    • Image Quality
    • Internal Regulation
    • Spatial Noise
    • Low-dropout Regulator
    • Parasite
    • Invisible
    • Image Sensor
    • Image Noise
    • Pixel Array
    • Temporal Noise
    • Aspect Ratio
    • Process Parameters
    • Recovery Time
    • Current Source
    • Transient Response
    • Output Current
    • Printed Circuit Board
    • Array Size
    • Bias Current
    • External Regulation
    • Output Load
    • Visible Light Images
    • PIN Photodiode
    • Dark Images
    • Global Operations
    • Large Aspect Ratio
• isbn_formats:
  • format: Print ISBN, value: 978-1-7281-3320-1, isbnType: New-2005
• authors:
  • Author Name: Ali E. Zadeh
    Affiliation: USC Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, USA
    Author URL: https://ieeexplore.ieee.org/author/37543589300
    ID: 37543589300
    Order: 1
    Author Affiliations:
    • USC Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, USA

Image Sensor

• sensor_type: CMOS
• resolution: 5 Megapixels (2592 x 1944)
• dynamic_range: Not specified
• pixel_size: 2.2 µm x 2.2 µm
• dark_current: Few microamperes for the entire pixel array during power-down; maximum output current pulse may reach 30 mA during power-up (exact dark current not specified).

Optical Data

• focal_length: Not specified
• aperture: Not specified
• field_of_view: Not specified
• distortion: Not specified

Performance Metrics

• frame_rate: 30 fps
• noise: RMS noise using external regulator: 20 LSBs; RMS noise using internal LDO: 4 LSBs.

Applications & Benefits

• cell_imaging: Not specified
• benefits: Reduces row-wise fixed-pattern noise significantly, making it invisible compared to temporal pixel noise.

Supporting Organizations

• supported_by: University of Southern California

Manuscript Details

• publication_date: 12-14 Oct 2020

Relevancy Score

• score: 10
• missing_fields:
  • dynamic_range
  • signal_to_noise_ratio
  • sensitivity
  • shutter_speed
  • power_consumption
  • focal_length
  • aperture
  • field_of_view
  • distortion
  • cell_imaging

Processed JSON Filename

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