The Experts below are selected from a list of 37926 Experts worldwide ranked by ideXlab platform
Robert D Lorenz - One of the best experts on this subject based on the ideXlab platform.
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sensing power mosfet Junction Temperature using gate drive turn on current transient properties
IEEE Transactions on Industry Applications, 2016Co-Authors: He Niu, Robert D LorenzAbstract:Junction Temperature sensing for high-bandwidth power MOSFET Junction Temperature protection is usually achieved on the power converter’s high power side, by directly monitoring the power switches with additional Temperature detectors. This requires special considerations for high voltage, high current, high Temperature, and EMI protection. This paper presents a new method applied on the power converter’s low power side (MOSFET gate drive) so that Junction Temperature sensing can be integrated into MOSFET gate drive. For the purpose of demonstrating MOSFET Junction Temperature sensing, a push–pull gate drive is applied to a switching current divider circuit. The gate drive turn-on current transient waveform is used for MOSFET Junction Temperature estimation. A “gate drive-MOSFET” switching dynamic model is implemented indicating the mechanisms of MOSFET gate drive output dynamics. Modeling includes gate-drive push–pull output, gate drive output parasitics, power MOSFET intrinsic parameters, PCB parasitics, and load parasitics. LTSpice simulation of this model is studied and compared with experimental results.
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sensing igbt Junction Temperature using gate drive output transient properties
Applied Power Electronics Conference, 2015Co-Authors: He Niu, Robert D LorenzAbstract:Insulated Gate Bipolar Transistor (IGBT) Junction Temperature sensing is normally achieved with a Temperature detector. To optimize accuracy, the Temperature detectors are placed very close to the power semiconductor chip or embedded on the power semiconductor die. This is inconvenient for power integration and requires further consideration for high voltage, high current, EMI protection, and the detector's thermal-mechanical stress. This paper presents a non-invasive method that integrates Junction Temperature sensing into the IGBT gate drive and enables high bandwidth sensing. In order to demonstrate the IGBT Junction Temperature sensing, an IGBT power module is implemented in an H-bridge, and driven by four push-pull type gate drives. The gate drive switching transient properties are used for IGBT Junction Temperature estimation. The “gate drive-IGBT” switching properties are modeled to explain the Junction-Temperature-dependent gate drive output dynamics. A hardware implementation for IGBT Junction Temperature extraction is provided. Experimental results are compared with circuit Spice model simulation.
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sensing power mosfet Junction Temperature using circuit output current ringing decay
Energy Conversion Congress and Exposition, 2013Co-Authors: He Niu, Robert D LorenzAbstract:Junction Temperature sensing requirements for fast MOSFET Junction Temperature control and high power fast switching power converter protection are not easily met with non-intrusive techniques. This paper presents a non-invasive circuit model-based sensing method suitable for a high bandwidth, hard-switching converter power MOSFET Junction Temperature estimation without any additional Temperature detector. For the purpose of demonstrating MOSFET Junction Temperature sensing, a chopper circuit is used. The ringing superimposed with a circuit load current is used for MOSFET Junction Temperature estimation. A `gate drive-RDS-on-L-C' resonant model is implemented indicating the mechanism of power MOSFET turn-on dynamics. Modeling includes the gate-drive output parasitics, power MOSFET intrinsic parameters, PCB parasitics and load parasitics. To evaluate the methodology, LTSpice Simulation and experimental results are studied.
Maoxing Zhou - One of the best experts on this subject based on the ideXlab platform.
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research on the Junction Temperature characteristic of gan light emitting diodes on si substrate
Journal of Luminescence, 2007Co-Authors: Fengyi Jiang, Youqun Li, Wenqing Fang, Chunlan Mo, Maoxing ZhouAbstract:Junction Temperature is one of the key parameter of light emitting diodes (LEDs). The Junction Temperature characteristic of GaN-based blue LEDs on Si substrate was first reported. The results indicated that the Junction Temperature of GaN LEDs on Si substrate is lower than that of GaN LEDs on sapphire, which is attributed to the good thermal conductivity of Si substrate.
He Niu - One of the best experts on this subject based on the ideXlab platform.
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sensing power mosfet Junction Temperature using gate drive turn on current transient properties
IEEE Transactions on Industry Applications, 2016Co-Authors: He Niu, Robert D LorenzAbstract:Junction Temperature sensing for high-bandwidth power MOSFET Junction Temperature protection is usually achieved on the power converter’s high power side, by directly monitoring the power switches with additional Temperature detectors. This requires special considerations for high voltage, high current, high Temperature, and EMI protection. This paper presents a new method applied on the power converter’s low power side (MOSFET gate drive) so that Junction Temperature sensing can be integrated into MOSFET gate drive. For the purpose of demonstrating MOSFET Junction Temperature sensing, a push–pull gate drive is applied to a switching current divider circuit. The gate drive turn-on current transient waveform is used for MOSFET Junction Temperature estimation. A “gate drive-MOSFET” switching dynamic model is implemented indicating the mechanisms of MOSFET gate drive output dynamics. Modeling includes gate-drive push–pull output, gate drive output parasitics, power MOSFET intrinsic parameters, PCB parasitics, and load parasitics. LTSpice simulation of this model is studied and compared with experimental results.
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sensing igbt Junction Temperature using gate drive output transient properties
Applied Power Electronics Conference, 2015Co-Authors: He Niu, Robert D LorenzAbstract:Insulated Gate Bipolar Transistor (IGBT) Junction Temperature sensing is normally achieved with a Temperature detector. To optimize accuracy, the Temperature detectors are placed very close to the power semiconductor chip or embedded on the power semiconductor die. This is inconvenient for power integration and requires further consideration for high voltage, high current, EMI protection, and the detector's thermal-mechanical stress. This paper presents a non-invasive method that integrates Junction Temperature sensing into the IGBT gate drive and enables high bandwidth sensing. In order to demonstrate the IGBT Junction Temperature sensing, an IGBT power module is implemented in an H-bridge, and driven by four push-pull type gate drives. The gate drive switching transient properties are used for IGBT Junction Temperature estimation. The “gate drive-IGBT” switching properties are modeled to explain the Junction-Temperature-dependent gate drive output dynamics. A hardware implementation for IGBT Junction Temperature extraction is provided. Experimental results are compared with circuit Spice model simulation.
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sensing power mosfet Junction Temperature using circuit output current ringing decay
Energy Conversion Congress and Exposition, 2013Co-Authors: He Niu, Robert D LorenzAbstract:Junction Temperature sensing requirements for fast MOSFET Junction Temperature control and high power fast switching power converter protection are not easily met with non-intrusive techniques. This paper presents a non-invasive circuit model-based sensing method suitable for a high bandwidth, hard-switching converter power MOSFET Junction Temperature estimation without any additional Temperature detector. For the purpose of demonstrating MOSFET Junction Temperature sensing, a chopper circuit is used. The ringing superimposed with a circuit load current is used for MOSFET Junction Temperature estimation. A `gate drive-RDS-on-L-C' resonant model is implemented indicating the mechanism of power MOSFET turn-on dynamics. Modeling includes the gate-drive output parasitics, power MOSFET intrinsic parameters, PCB parasitics and load parasitics. To evaluate the methodology, LTSpice Simulation and experimental results are studied.
E F Schubert - One of the best experts on this subject based on the ideXlab platform.
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Junction Temperature measurement in gan ultraviolet light emitting diodes using diode forward voltage method
Applied Physics Letters, 2004Co-Authors: Y Xi, E F SchubertAbstract:A theoretical model for the dependence of the diode forward voltage (Vf) on Junction Temperature (Tj) is developed. An expression for dVf∕dT is derived that takes into account all relevant contributions to the Temperature dependence of the forward voltage including the intrinsic carrier concentration, the band-gap energy, and the effective density of states. Experimental results on the Junction Temperature of GaN ultraviolet light-emitting diodes are presented. Excellent agreement between the theoretical and experimental Temperature coefficient of the forward voltage (dVf∕dT) is found. A linear relation between the Junction Temperature and the forward voltage is found.
Y Xi - One of the best experts on this subject based on the ideXlab platform.
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Junction Temperature in ultraviolet light emitting diodes
Japanese Journal of Applied Physics, 2005Co-Authors: Y Xi, Thomas Gessmann, J Q Xi, Jay M Shah, Fred E Schubert, A J Fischer, Mary H Crawford, K H A Bogart, Andrew A AllermanAbstract:The Junction Temperature and thermal resistance of AlGaN and GaInN ultraviolet (UV) light-emitting diodes (LEDs) emitting at 295 and 375 nm, respectively, are measured using the Temperature coefficient of diode-forward voltage. An analysis of the experimental method reveals that the diode-forward voltage has a high accuracy of ±3°C. A comprehensive theoretical model for the dependence of diode-forward voltage (Vf) on Junction Temperature (Tj) is developed taking into account the Temperature dependence of the energy gap and the Temperature coefficient of diode resistance. The difference between the Junction voltage Temperature coefficient (dVj/dT) and the forward voltage Temperature coefficient (dVf/dT) is shown to be caused by diode series resistance. The data indicate that the n-type neutral regions are the dominant resistive element in deep-UV devices. A linear relationship between Junction Temperature and current is found. Junction Temperature is also measured by the emission-peak-shift method. The high-energy slope of the spectrum is explored in the measurement of carrier Temperature.
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Junction Temperature in light emitting diodes assessed by different methods
Light-emitting diodes : research manufacturing and application. Conference, 2005Co-Authors: Sameer Chhajed, Y Xi, Thomas Gessmann, J Q Xi, Jay M Shah, Fred E SchubertAbstract:The Junction Temperature of red (AlGaInP), green (GaInN), blue (GaInN), and ultraviolet (GaInN) light-emitting diodes (LEDs) is measured using the Temperature coefficients of the diode forward voltage and of the emission-peak energy. The Junction Temperature increases linearly with DC current as the current is increased from 10 mA to 100 mA. For comparison, the emission-peak-shift method is also used to measure the Junction Temperature. The emission-peak-shift method is in good agreement with the forward-voltage method. The carrier Temperature is measured by the high-energy-slope method, which is found to be much higher than the lattice Temperature at the Junction. Analysis of the experimental methods reveals that the forward-voltage method is the most sensitive and its accuracy is estimated to be ± 3°C. The peak position of the spectra is influenced by alloy broadening, polarization, and quantum confined Stark effect thereby limiting the accuracy of the emission-peak-shift method to ±15°C. A detailed analysis of the Temperature dependence of a tri-chromatic white LED source (consisting of three types of LEDs) is performed. The analysis reveals that the chromaticity point shifts towards the blue, the color-rendering index (CRI) decreases, the color Temperature increases, and the luminous efficacy decreases as the Junction Temperature increases. A high CRI > 80 can be maintained, by adjusting the LED power so that the chromaticity point is conserved.
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Junction Temperature measurement in gan ultraviolet light emitting diodes using diode forward voltage method
Applied Physics Letters, 2004Co-Authors: Y Xi, E F SchubertAbstract:A theoretical model for the dependence of the diode forward voltage (Vf) on Junction Temperature (Tj) is developed. An expression for dVf∕dT is derived that takes into account all relevant contributions to the Temperature dependence of the forward voltage including the intrinsic carrier concentration, the band-gap energy, and the effective density of states. Experimental results on the Junction Temperature of GaN ultraviolet light-emitting diodes are presented. Excellent agreement between the theoretical and experimental Temperature coefficient of the forward voltage (dVf∕dT) is found. A linear relation between the Junction Temperature and the forward voltage is found.
