KEYWORDS: Signal detection, Cadmium sulfide, Signal to noise ratio, Image sensors, High dynamic range imaging, Capacitors, Sensors, Logic, Photodiodes, Photons
This paper presents a high dynamic range imaging sensor for detection of low light level signals. The sensor
utilises a 12x12 array of large 150μm x 150μm pixels. The readout circuitry allows for multiple readout options
including; multiple sampling (which allows for techniques such as Correlated Double Sampling (CDS)) and Time
to Digital Conversion (TDC) techniques, operated both independently and under the same integration period.
Scope for test patterns is also present in the design. All samples taken from the pixels before during and after
exposure are converted digitally through the use of a single slope ADC utilising a 10 bit DAC and a comparator.
No sample and hold capacitor is present. 4x10 bit SRAMs (Static Random Access Memory) per pixel are utilised
to record multiple samples, or act as a counter for the TDC mode of operation. The large dynamic range of the
system is attributable to both the novel timing system implemented within the multiple sampling mode of
operation and the TDC mode of operation (operated independently or intermittently within the same
integration time), which combines the use of 4x10 bit SRAMs with the 10 bit DAC to produce a counter capable
of monitoring the pixel signal over extremely long integration times; in this case up to 30 seconds.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.