A 32 Times 32 Isfet Chemical Sensing Array With Integrated Trapped Charge And Gain Compensation

• doi: 10.1109/JSEN.2017.2722043
• title: A 32 $\times$ 32 ISFET Chemical Sensing Array With Integrated Trapped Charge and Gain Compensation
• publisher: IEEE
• isbn:
• issn: 2379-9153
• rank: 416
• access_type: LOCKED
• content_type: Journals
• abstract: This paper presents a CMOS-based 32 × 32 ion-sensitive field-effect transistor (ISFET) system-on-chip for real-time ion imaging. Fabricated in an unmodified 0.35-μm CMOS technology, the ISFET sensor array is based on a pixel topology, which uses capacitive feedback to improve signal attenuation due to passivation capacitance and a low-leakage floatinggate reset followed by a digital correlated double sampling to robustly remove unwanted trapped charge-induced dc offset. An automatic gain calibration (AGC) is used to perform realtime calibration and guarantee all sensors that have the same gain with a 99% accuracy, and combining all these mechanisms guarantees an average pixel voltage variation of 14.3 mV after gain is applied when measured over multiple dies. The full array is experimentally shown to be capable of real-time ion imaging of pH, with an intrinsic sensitivity of 39.6mV/pH and a scan rate of 9.3 frames/s when running the AGC, with a total power consumption of 10.2 mW.
• article_number: 7964654
• pdf_url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7964654
• html_url: https://ieeexplore.ieee.org/document/7964654/
• abstract_url: https://ieeexplore.ieee.org/document/7964654/
• publication_title: IEEE Sensors Journal
• conference_location:
• conference_dates:
• publication_number: 7361
• is_number: 7987843
• publication_year: 2017
• publication_date: 15 Aug.15, 2017
• start_page: 5276
• end_page: 5284
• citing_paper_count: 49
• citing_patent_count: 0
• download_count: 1402
• insert_date: 20170630
• index_terms:
  • ieee_terms:
    • Sensor arrays
    • Capacitance
    • Chemicals
    • Calibration
    • Automatic generation control
    • Logic gates
  • author_terms:
    • ISFET
    • CMOS sensor
    • sensor array
    • offset cancellation
    • automatic gain calibration
    • pH sensor
  • dynamic_index_terms:
    • Charge Trapping
    • Ion-sensitive Field-effect Transistor
    • Sensor Array
    • CMOS Technology
    • Automatic Calibration
    • Operating System
    • Low-pass
    • Low-pass Filter
    • Output Signal
    • Final Output
    • Sensory Function
    • Sensor Performance
    • Chemical Signals
    • Chemical Information
    • Sine Wave
    • Output Response
    • Polymeric Membranes
    • Noise Floor
    • Drift Rate
    • Random Drift
    • Low Leakage
    • Gain Variation
    • Chemical Imaging
    • Off-chip Memory
    • Array Surface
    • Array Output
    • Phase Offset
• authors:
  • Author Name: Yuanqi Hu
    Affiliation: Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.
    Author URL: https://ieeexplore.ieee.org/author/37713724100
    ID: 37713724100
    Order: 1
    Author Affiliations:
    • Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.
  • Author Name: Nicolas Moser
    Affiliation: Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.
    Author URL: https://ieeexplore.ieee.org/author/37085398603
    ID: 37085398603
    Order: 2
    Author Affiliations:
    • Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.
  • Author Name: Pantelis Georgiou
    Affiliation: Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.
    Author URL: https://ieeexplore.ieee.org/author/37302145800
    ID: 37302145800
    Order: 3
    Author Affiliations:
    • Centre for Bio–Inspired Technology, Institute of Biomedical Engineering, Imperial College London, London, U.K.

Image Sensor

• sensor_type: CMOS
• resolution: 1024 ISFET sensors (32x32 pixel architecture)
• dynamic_range: 10 pH
• pixel_size: 50µm x 50µm per ISFET
• dark_current: Not explicitly stated; implies low leakage due to electronic design improvements.

Optical Data

• focal_length: Not applicable
• aperture: Not applicable
• field_of_view: Not applicable
• distortion: Not applicable

Performance Metrics

• frame_rate: 9.3 frames/s
• signal_to_noise_ratio: Not explicitly stated
• sensitivity: 39.6 mV/pH
• shutter_speed: Not applicable
• power_consumption: 10.2 mW
• noise: Average noise floor of 2.6 mV.

Applications & Benefits

• cell_imaging: pH monitoring and imaging in a microfluidic flow cell for chemical reactions.
• benefits: Integration of ISFETs in CMOS allows for low-cost, high-density sensing arrays with real-time pH imaging capabilities.

Supporting Organizations

• supported_by: Imperial College London, Centre for Bio-Inspired Technology

Manuscript Details

• publication_date: 15 Aug.15, 2017

Relevancy Score

• score: 9
• missing_fields:
  • fill factor
  • quantum efficiency
  • readout speed
  • noise sources
  • analog-to-digital conversion techniques
  • microlenses
  • on-chip colour filters
  • global or rolling shutters
  • backside illumination

Processed JSON Filename

request_12b340a4-7666-4ba5-8990-e12ac1c0fb0f-a_32_times_32_isfet_chemical_sensing_array_with_integrated_trapped_charge_and_gain_compensation.json