1 F Noise Reduction Using Inpixel Chopping In Cmos Image Sensors

• doi: 10.1109/LSSC.2018.2879722
• title: 1/ $f$ Noise Reduction Using In-Pixel Chopping in CMOS Image Sensors
• publisher: IEEE
• isbn:
• issn: 2573-9603
• rank: 8
• access_type: LOCKED
• content_type: Journals
• abstract: In this letter, an in-pixel chopping technique to reduce the low-frequency or 1/f noise of the source follower (SF) transistor in an active pixel sensor (APS) is presented. The SF low-frequency noise is modulated at higher frequencies through chopping, implemented inside the pixel, and in later stage eliminated using low-pass filtering. To implement the chopping, the conventional 3T APS architecture is modified, with only one additional transistor of minimum size per pixel. Reduction in the noise also enhances the dynamic range of the image sensor. The prototype sensor, consists of a 128 × 128 sized pixel array with in-pixel chopping and column-level read-out circuit, is fabricated in AMS 0.35-μm CMOS OPTO process. The pixel is laid out at the pitch of 10.5 μm with a fillfactor of 30%. To validate the proposed technique a 2 × 2 pixel array is characterized. The output noise integrated in the frequency band from 1 Hz to 20 kHz is measured as 210 μVRMS and 191 μVRMS at chopping frequency (fch) of 4 MHz and 8 MHz, respectively, which shows a reduction in the noise power by 13.3 and 14.2 dB, respectively.
• article_number: 8525287
• pdf_url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8525287
• html_url: https://ieeexplore.ieee.org/document/8525287/
• abstract_url: https://ieeexplore.ieee.org/document/8525287/
• publication_title: IEEE Solid-State Circuits Letters
• conference_location:
• conference_dates:
• publication_number: 8011414
• is_number: 8538892
• publication_year: 2018
• publication_date: June 2018
• start_page: 146
• end_page: 149
• citing_paper_count: 4
• citing_patent_count: 0
• download_count: 1636
• insert_date: 20181106
• index_terms:
  • ieee_terms:
    • Low-frequency noise
    • Photodiodes
    • Choppers (circuits)
    • Switches
    • 1/f noise
    • Transistors
  • author_terms:
    • 1/f noise
    • chopper amplifier
    • CMOS image sensors
    • dynamic range (DR)
    • low-frequency noise
  • dynamic_index_terms:
    • Denoising
    • Noise Reduction
    • Image Sensor
    • Camera Sensor
    • Low-pass
    • Low-pass Filter
    • Minimum Size
    • Frequency Band
    • Noise Power
    • Low-frequency Noise
    • Pixel Array
    • Sensor Pixel
    • Sensor Prototype
    • Random Noise
    • Channel Noise
    • Output Signal
    • Sample Holder
    • Thermal Noise
    • Current Noise
    • Clock Signal
    • Amplification Stage
    • Non-overlapping Intervals
    • Non-overlapping Time Intervals
    • Corner Frequency
    • Output Pixel
• authors:
  • Author Name: Kapil Jainwal
    Affiliation: ECE Department, LNM Institute of Information Technology, Jaipur, India
    Author URL: https://ieeexplore.ieee.org/author/38189472900
    ID: 38189472900
    Order: 1
    Author Affiliations:
    • ECE Department, LNM Institute of Information Technology, Jaipur, India
  • Author Name: Chandani Anand
    Affiliation: Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi, India
    Author URL: https://ieeexplore.ieee.org/author/37901669700
    ID: 37901669700
    Order: 2
    Author Affiliations:
    • Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi, India
  • Author Name: Mukul Sarkar
    Affiliation: Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi, India
    Author URL: https://ieeexplore.ieee.org/author/37394227700
    ID: 37394227700
    Order: 3
    Author Affiliations:
    • Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi, India

Image Sensor

• sensor_type: CMOS
• resolution: 128x128
• dynamic_range: Not explicitly provided in decibels (dB), but improved through noise reduction techniques.
• pixel_size: 10.5 µm
• dark_current: Not explicitly provided in electrons per second (e-/s).

Optical Data

• focal_length: Not provided.
• aperture: Not provided.
• field_of_view: Not provided.
• distortion: Not provided.

Performance Metrics

• frame_rate: Not provided explicitly, but operates in rolling shutter mode.
• signal_to_noise_ratio: Improved by 14.2 dB after in-pixel chopping, indicating high image quality.
• sensitivity: 2.46 V/lx-s
• shutter_speed: Not provided.
• power_consumption: 346 μW (or 0.346 mW) at maximum consumption.
• noise: Integrated noise power reduced to 191.2 μVRMS at fch=8 MHz.

Applications & Benefits

• cell_imaging: Improves image quality in medical applications, particularly low-light conditions.
• benefits: Reduction in low-frequency 1/f noise improves dynamic range and image quality.

Supporting Organizations

• supported_by: Indian Institute of Technology Delhi, LNM Institute of Information Technology.

Manuscript Details

• publication_date: June 2018

Relevancy Score

• score: 9
• missing_fields:
  • quantum_efficiency
  • readout_speed
  • temporal_noise
  • fixed-pattern_noise
  • microlenses
  • on-chip_colour_filters
  • global_or_rolling_shutters
  • backside_illumination

Processed JSON Filename

request_34136bd1-f06e-4602-a141-23bc347b8a41-1_f__noise_reduction_using_inpixel_chopping_in_cmos_image_sensors.json