A family of low-voltage power-efficient class AB CMOS operational transconductance amplifiers (OTAs) is described. It is based on the combination of adaptive biasing techniques and resistive local common-mode feedback...
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A family of low-voltage power-efficient class AB CMOS operational transconductance amplifiers (OTAs) is described. It is based on the combination of adaptive biasing techniques and resistive local common-mode feedback (LCMFB), which provides increased dynamic current boosting and gain-bandwidth product (GBW). The different classes of AB OTA topologies presented result from the combination of various adaptive biasing schemes and LCMFB. A 0.5-/spl mu/m CMOS implementation of three different OTAs shows enhancement factors of slew-rate and GBW up to 280 and 3.6, respectively, for an 80-pF load, compared to a conventional class A OTA with the same quiescent currents and supply voltage. The overhead in area, noise, and static power consumption, is minimal.
Two-photon absorption was measured in AlGaInAs strained-layer multiple-quantum-well active waveguide devices at wavelengths near the 1575 nm band-gap. Values around 400 cm/GW were obtained, much larger than that predi...
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ISBN:
(纸本)1557527776
Two-photon absorption was measured in AlGaInAs strained-layer multiple-quantum-well active waveguide devices at wavelengths near the 1575 nm band-gap. Values around 400 cm/GW were obtained, much larger than that predicted by a commonly used scaling law.
Two schemes for power efficient gain programmable V-I conversion based on class AB CMOS mirrors are introduced. These allow for high-speed gain programmable precision rectification. Experimental results from a test ch...
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Two schemes for power efficient gain programmable V-I conversion based on class AB CMOS mirrors are introduced. These allow for high-speed gain programmable precision rectification. Experimental results from a test chip prototype, in 0.5 /spl mu/m CMOS technology with /spl plusmn/1 V supplies are shown that validate the proposed circuits.
Unlike the well-known bang-bang control for continuous plants, the closed-form time optimal control for discrete time plants was obtained only recently (Z. Gao, 2004, J. Han, 1999). It is shown in this paper that this...
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Unlike the well-known bang-bang control for continuous plants, the closed-form time optimal control for discrete time plants was obtained only recently (Z. Gao, 2004, J. Han, 1999). It is shown in this paper that this new discrete time optimal control (DTOC) law offers a practical alternative to bang-bang control. A particularly interesting property of DTOC is that the control signal is not always bang-bang. Instead of constant chattering, DTOC can produce a smooth control signal that results in a similar performance to that of the bang-bang control. Helpful insight is offered on how to maintain the smoothness of control signal in the presence of significant sensor noises. Superior robustness of the new control law is demonstrated for a general second order system with substantial dynamic uncertainties. Implementation issues and the tuning of the control parameters are also discussed. Finally, the performance of the new control law is examined in an industrial motion control case study and a computer hard disk drive problem.
The use of simple and extremely accurate voltage buffers to drive two MOS transistors in triode region is employed to obtain a very linear voltage-to-current conversion. Transconductance can be simply and precisely ad...
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The use of simple and extremely accurate voltage buffers to drive two MOS transistors in triode region is employed to obtain a very linear voltage-to-current conversion. Transconductance can be simply and precisely adjusted using DC level shifters. Measurement results of a balanced transconductor fabricated in a 0.5-μm CMOS technology show a -54 dB THD at 100 kHz for 80-μA peak-to-peak outputs, using a 2-V supply. Silicon area is 0.07 mm2 and static power consumption is 0.92 mW.
A novel technique for implementing class AB differential input stages is proposed. It is well suited for low voltage operation, and can be applied to single-stage or two-stage OTAs in continuous-time or sampled-data s...
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A novel technique for implementing class AB differential input stages is proposed. It is well suited for low voltage operation, and can be applied to single-stage or two-stage OTAs in continuous-time or sampled-data systems. In order to illustrate this approach a novel OTA is presented, combining the input stage proposed and local common-mode feedback with two resistors to obtain high slew rate and very low static power consumption. Measurement results from a 0.5-μm CMOS implementation with supply voltages of ±1 V show a slew rate of 50 V/μs for an 80-pF load capacitance, and a static power consumption of only 120 μW. Silicon area for this OTA is 0.024 mm2.
A new CMOS transconductor with wide transconductance tuning range and very low distortion is presented. The input stage features a highly linear conversion of the input voltage into current form. Electronically progra...
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A new CMOS transconductor with wide transconductance tuning range and very low distortion is presented. The input stage features a highly linear conversion of the input voltage into current form. Electronically programmable current mirrors able to operate in weak or moderate inversion provide a continuous transconductance tuning range of two decades without affecting the large input signal range available. Measurement results of a prototype fabricated in a 0.5-μm CMOS technology show a THD of -66.5 dB for a 100-kHz differential input of 2 Vpp.
We aligned two fundamentally different models of smallpox transmission after a bioterrorist attack: A location-explicit multi-agent model (Bio- War) and the conventional epidemiological box model, called a SIR model f...
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A simple modification to a conventional single-stage OTA based on the combined use of local common-mode feedback and very efficient class AB input stages leads to three proposals for class AB amplifier topologies. The...
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A simple modification to a conventional single-stage OTA based on the combined use of local common-mode feedback and very efficient class AB input stages leads to three proposals for class AB amplifier topologies. They operate at low voltage and feature very low static power consumption, bandwidth enhancement, and very high slew rate. Measurement results in a 0.5-/spl mu/m CMOS technology confirm the mentioned improvements.
The use of simple and extremely accurate voltage buffers to drive two MOS transistors in triode region is employed to obtain a very linear voltage-to-current conversion. Transconductance can be simply and precisely ad...
详细信息
The use of simple and extremely accurate voltage buffers to drive two MOS transistors in triode region is employed to obtain a very linear voltage-to-current conversion. Transconductance can be simply and precisely adjusted using DC level shifters. Measurement results of a balanced transconductor fabricated in a 0.5-/spl mu/m CMOS technology show a -54 dB THD at 100 kHz for 80-/spl mu/A peak-to-peak outputs, using a 2-V supply. Silicon area is 0.07 mm/sub 2/ and static power consumption is 0.92 mW.
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