Electrical property modelling of photodiode type CMOS active pixel sensor (APS)
01 Jan 2005-pp 371-375
TL;DR: In this article, the electrical characteristics of photodiode (PD) type CMOS active pixel sensor (APS) pixel were modeled using BSIM3v3 threshold voltage equation for hand calculation with better than 2% peak-to-peak error for full back-gate bias and supply voltages for CMOS process technologies.
Abstract: In this research, few electrical characteristics of photodiode (PD) type CMOS active pixel sensor (APS) pixel were modeled. BSIM3v3 threshold voltage equation was simplified for hand calculation with better than 2% peak-to-peak error for full back-gate bias and supply voltages for CMOS process technologies that has minimum feature sizes between 0.18/spl mu/m and 2.0/spl mu/m. Two fitting function coefficients (FFC) were included in the BSIM threshold model equations for simplification of the equation. FFCs were extracted by using circuit simulation for given process. Using the simplified threshold equation, electrical characteristics of 3T CMOS PD-APS pixel were modeled. Models include; photodiode reset level, pixel amplifier signal range, and pixel reset level boosting factor. Models were evaluated by using wide variety of available CMOS process technologies and compared with the simulation results. Pixel reset level and signal range model equations produce better than 6% and 12% peak-to-peak accuracy with simple hand calculation, respectively. Models were also confirmed with a designed photodiode-type CMOS APS pixel. A CMOS photodiode type APS imager fabricated in a 0.5/spl mu/m, 2P3M, 5Volt CMOS process with 15/spl mu/m square pixel size was used for comparison.
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TL;DR: In this article, the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
Abstract: CMOS active pixel sensors (APS) have performance competitive with charge-coupled device (CCD) technology, and offer advantages in on-chip functionality, system power reduction, cost, and miniaturization. This paper discusses the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
1,182 citations
Journal Article•
TL;DR: In this article, the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
Abstract: CMOS active pixel sensors (APS) have performance competitive with charge-coupled device (CCD) technology, and offer advantages in on-chip functionality, system power reduction, cost, and miniaturization. This paper discusses the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
693 citations
TL;DR: The Berkeley short-channel IGFET model (BSIM) as discussed by the authors is an accurate and computationally efficient MOS transistor model, and its associated characterization facility for advanced integrated-circuit design is described.
Abstract: The Berkeley short-channel IGFET model (BSIM), an accurate and computationally efficient MOS transistor model, and its associated characterization facility for advanced integrated-circuit design are described. Both the strong-inversion and weak-inversion components of the drain current expression are included. In order to speed up the circuit-simulation execution time, the dependence of the drain current on the substrate bias has been modeled with a numerical approximation. This approximation also simplifies the transistor terminal-charge expressions. The charge model was derived from its drain-current counterpart to preserve consistency of device physics. Charge conservation is guaranteed in this model.
560 citations
"Electrical property modelling of ph..." refers background in this paper
...Threshold voltage and other physical parameters of MOS transistor are well defined and modeled for circuit simulators [3,4,5]....
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TL;DR: A new physical and continuous BSIM (Berkeley Short-Channel IGFET Model) I-V model in BSIM3v3 is presented for circuit simulation, which allows users to accurately describe the MOSFET characteristics over a wide range of channel lengths and widths for various technologies, and is attractive for statistical modeling.
Abstract: A new physical and continuous BSIM (Berkeley Short-Channel IGFET Model) I-V model in BSIM3v3 is presented for circuit simulation. Including the major physical effects in state-of-the art MOS devices, the model describes current characteristics from subthreshold to strong inversion as well as from the linear to the saturation operating regions with a single I-V expression, and guarantees the continuities of I/sub ds/, conductances and their derivatives throughout all V/sub gs/, V/sub ds/, and T/sub bs/, bias conditions. Compared with the previous BSIM models, the improved model continuity enhances the convergence property of the circuit simulators. Furthermore, the model accuracy has also been enhanced by including the dependencies of geometry and bias of parasitic series resistances, narrow width, bulk charge, and DIBL effects. The new model has the extensive built-in dependencies of important dimensional and processing parameters (e.g., channel length, width, gate oxide thickness, junction depth, substrate doping concentration, etc.). It allows users to accurately describe the MOSFET characteristics over a wide range of channel lengths and widths for various technologies, and is attractive for statistical modeling. The model has been implemented in the circuit simulators such as Spectre, Hspice, SmartSpice, Spice3e2, and so on.
177 citations
"Electrical property modelling of ph..." refers background or methods in this paper
...Threshold voltage and other physical parameters of MOS transistor are well defined and modeled for circuit simulators [3,4,5]....
[...]
...Threshold voltage of an NMOS transistor is given in (1), [3]....
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...In this research [2], few electrical parameters of photodiode (PD) type CMOS Active Pixel Sensor (APS) pixel were modelled for hand calculation by using modified BSIM3v3 model equations [3]....
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...A hybrid MOS threshold model equation was proposed [2] based on BSIM3v3 model equations [3] for simple and accurate representation of back-gate bias effect on the threshold voltage....
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01 Jan 1994
TL;DR: The Philips MOS MODEL 9 is presented with the successful confrontation with analog requirements, the scaling of parameters with geometry, the accuracy of the model over the whole geometry range of a process, its capabilities in the description of various processes at least down to 0.35 /spl mu/m and a comparison with advanced analog models available in commercial circuit simulators.
Abstract: Analog applications of MOS transistors in integrated circuits impose enhanced requirements on the compact MOS models used in circuit simulators. Here we present for the Philips MOS MODEL 9 the successful confrontation with these analog requirements, the scaling of parameters with geometry, the accuracy of the model over the whole geometry range of a process, its capabilities in the description of various processes at least down to 0.35 /spl mu/m and a comparison with advanced analog models available in commercial circuit simulators.<>
42 citations
"Electrical property modelling of ph..." refers background in this paper
...Threshold voltage and other physical parameters of MOS transistor are well defined and modeled for circuit simulators [3,4,5]....
[...]