The Experts below are selected from a list of 27825 Experts worldwide ranked by ideXlab platform
Hansjörg Scherer - One of the best experts on this subject based on the ideXlab platform.
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Noise-optimized ultrastable low-noise Current Amplifier
The Review of scientific instruments, 2019Co-Authors: Christian Krause, Dietmar Drung, Martin Gotz, Hansjörg SchererAbstract:We have developed a noise-optimized ultrastable low-noise Current Amplifier (ULCA) aimed at reducing the uncertainty at low Currents. It involves a thin-film resistor network with 6.75 GΩ at the high-ohmic path which reduces the noise level to 1.6 fA/Hz. Noise investigations as well as short-term and long-term stability studies were carried out. The stability of the input Current gain was measured using a cryogenic Current comparator at ±6.1 nA. Methods for investigating the measurement accuracy at low input Currents of about 100 pA at a level of below one part in 107 are introduced and experimentally verified. The performance of the noise-optimized ULCA is compared with that of the standard variant introduced in 2014. It is shown that the reduced noise floor is achieved without impairing the stability of the transresistance.
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validation of the ultrastable low noise Current Amplifier as travelling standard for small direct Currents
Metrologia, 2015Co-Authors: D Drung, Christian Krause, Martin Gotz, S P Giblin, S Djordjevic, Francois Piquemal, O Seron, Florentin Rengnez, E Pesel, Hansjörg SchererAbstract:An interlaboratory comparison of small-Current generation and measurement capability is presented with the ultrastable low-noise Current Amplifier (ULCA) acting as travelling standard. Various measurements at direct Currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA's transfer accuracy had been limited to about ±0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic Current comparator.
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ultrastable low noise Current Amplifier a novel device for measuring small electric Currents with high accuracy
Review of Scientific Instruments, 2015Co-Authors: D Drung, Christian Krause, Hansjörg Scherer, Ulrich Becker, F J AhlersAbstract:An ultrastable low-noise Current Amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational Amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold Current gain and the second performing a Current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA’s transfer coefficient is highly stable versus time, temperature, and Current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input Currents. A cryogenic Current comparator is used to calibrate both input Current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric Currents or the calibration of high-ohmic resistors.
S Pennisi - One of the best experts on this subject based on the ideXlab platform.
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cmos voltage feedback Current Amplifier
European Conference on Circuit Theory and Design, 2007Co-Authors: G Di Cataldo, Alfio Dario Grasso, S PennisiAbstract:A CMOS Current operational Amplifier with constant closed-loop bandwidth properties and high linearity is described and analyzed. A low-voltage architecture is proposed and designed using a 0.3-Cm process. The circuit operates under a 2- V supply and dissipates 130 VW, while exhibiting a closed-loop bandwidth of about 2 MHz using a fixed 100-kOmega feedback resistor.
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ECCTD - CMOS voltage feedback Current Amplifier
2007 18th European Conference on Circuit Theory and Design, 2007Co-Authors: G Di Cataldo, Alfio Dario Grasso, S PennisiAbstract:A CMOS Current operational Amplifier with constant closed-loop bandwidth properties and high linearity is described and analyzed. A low-voltage architecture is proposed and designed using a 0.3-Cm process. The circuit operates under a 2- V supply and dissipates 130 VW, while exhibiting a closed-loop bandwidth of about 2 MHz using a fixed 100-kOmega feedback resistor.
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High-speed CMOS unity-gain Current Amplifier
Microelectronics Journal, 2006Co-Authors: G Di Cataldo, R. Mita, S PennisiAbstract:Abstract A high-performance CMOS unity-gain Current Amplifier is proposed. The solution adopts two feedback loops to reduce the input resistance and a nested-Miller technique to provide frequency compensation. A design example using a 0.8 μm process and a 2 V supply is given and SPICE simulations show a bandwidth of 75 MHz, no slew-rate limitations and a settling time better than 50 ns, irrespective of the Current amplitude. Input and output resistances are better than 0.1 Ω and 15 MΩ, respectively. The input-referred white noise spectral density is 10 pA / Hz .
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High-Drive Current Amplifiers
CMOS Current Amplifiers, 1999Co-Authors: Giuseppe Palmisano, Gaetano Palumbo, S PennisiAbstract:The Current Amplifiers described in the previous chapter can profitably be used for on-chip signal processing, but their poor drive capability makes them unsuitable for driving off-chip loads. In these cases, a Current Amplifier with a class AB output stage is mandatory. To this end, the high-drive Current Amplifier becomes the natural front-end block for Current-mode ICs.
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High-drive CMOS Current Amplifier
IEEE Journal of Solid-State Circuits, 1998Co-Authors: Giuseppe Palmisano, Gaetano Palumbo, S PennisiAbstract:A high-performance Current Amplifier is proposed which is based on a folded-cascode transresistance Amplifier and a low-distortion class AB Current output stage. The loop gain of the transresistance Amplifier exhibits a gain bandwidth product of 10 MHz and a DC gain as high as 100 dB which allows accurate closed-loop operations to be achieved. Despite the intrinsic low-linearity performance of Current Amplifiers with respect to their voltage Amplifier counterpart, the proposed circuit provides an output Current of 7 mA with a total harmonic distortion (THD) better than -55 dB while requiring only 200 /spl mu/A of quiescent Current for the output transistors. The circuit was fabricated in a 1.2 /spl mu/m CMOS process, uses a 5 V power supply, and dissipates 4 mW.
D Drung - One of the best experts on this subject based on the ideXlab platform.
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validation of the ultrastable low noise Current Amplifier as travelling standard for small direct Currents
Metrologia, 2015Co-Authors: D Drung, Christian Krause, Martin Gotz, S P Giblin, S Djordjevic, Francois Piquemal, O Seron, Florentin Rengnez, E Pesel, Hansjörg SchererAbstract:An interlaboratory comparison of small-Current generation and measurement capability is presented with the ultrastable low-noise Current Amplifier (ULCA) acting as travelling standard. Various measurements at direct Currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA's transfer accuracy had been limited to about ±0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic Current comparator.
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ultrastable low noise Current Amplifier a novel device for measuring small electric Currents with high accuracy
Review of Scientific Instruments, 2015Co-Authors: D Drung, Christian Krause, Hansjörg Scherer, Ulrich Becker, F J AhlersAbstract:An ultrastable low-noise Current Amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational Amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold Current gain and the second performing a Current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA’s transfer coefficient is highly stable versus time, temperature, and Current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input Currents. A cryogenic Current comparator is used to calibrate both input Current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric Currents or the calibration of high-ohmic resistors.
Christian Krause - One of the best experts on this subject based on the ideXlab platform.
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Noise-optimized ultrastable low-noise Current Amplifier
The Review of scientific instruments, 2019Co-Authors: Christian Krause, Dietmar Drung, Martin Gotz, Hansjörg SchererAbstract:We have developed a noise-optimized ultrastable low-noise Current Amplifier (ULCA) aimed at reducing the uncertainty at low Currents. It involves a thin-film resistor network with 6.75 GΩ at the high-ohmic path which reduces the noise level to 1.6 fA/Hz. Noise investigations as well as short-term and long-term stability studies were carried out. The stability of the input Current gain was measured using a cryogenic Current comparator at ±6.1 nA. Methods for investigating the measurement accuracy at low input Currents of about 100 pA at a level of below one part in 107 are introduced and experimentally verified. The performance of the noise-optimized ULCA is compared with that of the standard variant introduced in 2014. It is shown that the reduced noise floor is achieved without impairing the stability of the transresistance.
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validation of the ultrastable low noise Current Amplifier as travelling standard for small direct Currents
Metrologia, 2015Co-Authors: D Drung, Christian Krause, Martin Gotz, S P Giblin, S Djordjevic, Francois Piquemal, O Seron, Florentin Rengnez, E Pesel, Hansjörg SchererAbstract:An interlaboratory comparison of small-Current generation and measurement capability is presented with the ultrastable low-noise Current Amplifier (ULCA) acting as travelling standard. Various measurements at direct Currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA's transfer accuracy had been limited to about ±0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic Current comparator.
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ultrastable low noise Current Amplifier a novel device for measuring small electric Currents with high accuracy
Review of Scientific Instruments, 2015Co-Authors: D Drung, Christian Krause, Hansjörg Scherer, Ulrich Becker, F J AhlersAbstract:An ultrastable low-noise Current Amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational Amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold Current gain and the second performing a Current-to-voltage conversion via an internal 1 MΩ reference resistor or, optionally, an external standard resistor. The ULCA’s transfer coefficient is highly stable versus time, temperature, and Current amplitude within the full dynamic range of ±5 nA. The low noise level of 2.4 fA/√Hz helps to keep averaging times short at small input Currents. A cryogenic Current comparator is used to calibrate both input Current gain and output transresistance, providing traceability to the quantum Hall effect. Within one week after calibration, the uncertainty contribution from short-term fluctuations and drift of the transresistance is about 0.1 parts per million (ppm). The long-term drift is typically 5 ppm/yr. A high-accuracy variant is available that shows improved stability of the input gain at the expense of a higher noise level of 7.5 fA/√Hz. The ULCA also allows the traceable generation of small electric Currents or the calibration of high-ohmic resistors.
Martin Gotz - One of the best experts on this subject based on the ideXlab platform.
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Noise-optimized ultrastable low-noise Current Amplifier
The Review of scientific instruments, 2019Co-Authors: Christian Krause, Dietmar Drung, Martin Gotz, Hansjörg SchererAbstract:We have developed a noise-optimized ultrastable low-noise Current Amplifier (ULCA) aimed at reducing the uncertainty at low Currents. It involves a thin-film resistor network with 6.75 GΩ at the high-ohmic path which reduces the noise level to 1.6 fA/Hz. Noise investigations as well as short-term and long-term stability studies were carried out. The stability of the input Current gain was measured using a cryogenic Current comparator at ±6.1 nA. Methods for investigating the measurement accuracy at low input Currents of about 100 pA at a level of below one part in 107 are introduced and experimentally verified. The performance of the noise-optimized ULCA is compared with that of the standard variant introduced in 2014. It is shown that the reduced noise floor is achieved without impairing the stability of the transresistance.
-
validation of the ultrastable low noise Current Amplifier as travelling standard for small direct Currents
Metrologia, 2015Co-Authors: D Drung, Christian Krause, Martin Gotz, S P Giblin, S Djordjevic, Francois Piquemal, O Seron, Florentin Rengnez, E Pesel, Hansjörg SchererAbstract:An interlaboratory comparison of small-Current generation and measurement capability is presented with the ultrastable low-noise Current Amplifier (ULCA) acting as travelling standard. Various measurements at direct Currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA's transfer accuracy had been limited to about ±0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic Current comparator.
