To minimize the power consumption with resources operating at multiple voltages a time-constrained algorithm is presented.The input to the scheme is an unscheduled data flow graph (DFG),and timing or resource constrai...To minimize the power consumption with resources operating at multiple voltages a time-constrained algorithm is presented.The input to the scheme is an unscheduled data flow graph (DFG),and timing or resource constraints.Partitioning is considered with scheduling in the proposed algorithm as multiple voltage design can lead to an increase in interconnection complexity at layout level.That is,in the proposed algorithm power consumption is first reduced by the scheduling step,and then the partitioning step takes over to decrease the interconnection complexity.The time-constrained algorithm has time complexity of O(n 2),where n is the number of nodes in the DFG.Experiments with a number of DSP benchmarks show that the proposed algorithm achieves the power reduction under timing constraints by an average of 46 5%.展开更多
A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short...A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short locking time. The voltage-controlled oscillator within the PLL consists of four-stage ring oscillators which are coupled to each other and oscillate with the same frequency and a phase shift of 45. The PLL is fabricated in 0. 1Stem CMOS technology. The measured phase noise of the PLL output at 500kHz offset from the 5GHz center frequency is - 102.6dBc/Hz. The circuit exhibits a capture range of 280MHz and a low RMS jitter of 2.06ps. The power dissipation excluding the output buffers is only 21.6roW at a 1.8V supply.展开更多
This paper presents a new design of a probe adjusting device intended to position pressure and temperature probes in a flow field. 5-hole, 3-hole and temperature probes can be moved in radial direction and freely rota...This paper presents a new design of a probe adjusting device intended to position pressure and temperature probes in a flow field. 5-hole, 3-hole and temperature probes can be moved in radial direction and freely rotated about their axis. The high actuation accuracy of 3.9 ktm in radial direction and 0.09~ in angular position is validated in a 2-stage-turbine test rig which is installed at the Institute of Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University. To meet the challenge to calculate the efficiency of a turbo machine which is mainly influenced by the temperature, all probe adjusting devices are positioned simultaneously and controlled by the MAS （measuring acquisition system） so that the same radial position in each stage is measured at the same time. For this purpose a new program has been developed to synchronize actuation and measurement. The slim design of 60 mm width allows measurement between the stages of turbo machines with small axial distances between vane and blade. In addition a CFD/FEA shows how the design and combination of materials compensate the thermal expansion of the engine during operation. This allows a minimal safety distance of 0.2 mm between rotor and probe to enable measurement as close to the physical boundary as possible. The actuation accuracy is demonstrated with pressure, temperature and angle distribution plots. It is also shown that the resolution of the measuring points, and therefore the actuation distances, has a large impact on the flow field analysis and should be set as high as possible. However the measuring time has to be taken into account.展开更多
The paper describes experiments on formation of a plasma channel with imbedded B-field for transporting high power ion beam. The plasma was generated with a 5-turn loop inductive antenna driven by an H-bridge type RF ...The paper describes experiments on formation of a plasma channel with imbedded B-field for transporting high power ion beam. The plasma was generated with a 5-turn loop inductive antenna driven by an H-bridge type RF generator. The azimuthal B-field in the channel of 0.5-1.5 kG was formed by a pulsed current from external capacitor bank. Control of the hydrogen gas pressure was provided by an electromagnetic puffvalve. The paper describes experimental devices and results on the generated plasma parameters as function of RF frequency, antenna voltage, pulse duration and puffgas pressure. When operating at-1 kG B-field, ambient gas pressure in the range of few -10 mTorr, and 5 kV antenna voltage at resonant frequency of 150 kHz, the plasma density range was （3-7）×10^12 cm3 with a temperature of a few eV.展开更多
The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(...The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) biasing.In these applications,a regulator with small volume,fewer external components and high efficiency is highly desired.This paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as well.With projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is realized.With projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control circuitry.Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.展开更多
文摘To minimize the power consumption with resources operating at multiple voltages a time-constrained algorithm is presented.The input to the scheme is an unscheduled data flow graph (DFG),and timing or resource constraints.Partitioning is considered with scheduling in the proposed algorithm as multiple voltage design can lead to an increase in interconnection complexity at layout level.That is,in the proposed algorithm power consumption is first reduced by the scheduling step,and then the partitioning step takes over to decrease the interconnection complexity.The time-constrained algorithm has time complexity of O(n 2),where n is the number of nodes in the DFG.Experiments with a number of DSP benchmarks show that the proposed algorithm achieves the power reduction under timing constraints by an average of 46 5%.
文摘A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short locking time. The voltage-controlled oscillator within the PLL consists of four-stage ring oscillators which are coupled to each other and oscillate with the same frequency and a phase shift of 45. The PLL is fabricated in 0. 1Stem CMOS technology. The measured phase noise of the PLL output at 500kHz offset from the 5GHz center frequency is - 102.6dBc/Hz. The circuit exhibits a capture range of 280MHz and a low RMS jitter of 2.06ps. The power dissipation excluding the output buffers is only 21.6roW at a 1.8V supply.
文摘This paper presents a new design of a probe adjusting device intended to position pressure and temperature probes in a flow field. 5-hole, 3-hole and temperature probes can be moved in radial direction and freely rotated about their axis. The high actuation accuracy of 3.9 ktm in radial direction and 0.09~ in angular position is validated in a 2-stage-turbine test rig which is installed at the Institute of Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University. To meet the challenge to calculate the efficiency of a turbo machine which is mainly influenced by the temperature, all probe adjusting devices are positioned simultaneously and controlled by the MAS （measuring acquisition system） so that the same radial position in each stage is measured at the same time. For this purpose a new program has been developed to synchronize actuation and measurement. The slim design of 60 mm width allows measurement between the stages of turbo machines with small axial distances between vane and blade. In addition a CFD/FEA shows how the design and combination of materials compensate the thermal expansion of the engine during operation. This allows a minimal safety distance of 0.2 mm between rotor and probe to enable measurement as close to the physical boundary as possible. The actuation accuracy is demonstrated with pressure, temperature and angle distribution plots. It is also shown that the resolution of the measuring points, and therefore the actuation distances, has a large impact on the flow field analysis and should be set as high as possible. However the measuring time has to be taken into account.
文摘The paper describes experiments on formation of a plasma channel with imbedded B-field for transporting high power ion beam. The plasma was generated with a 5-turn loop inductive antenna driven by an H-bridge type RF generator. The azimuthal B-field in the channel of 0.5-1.5 kG was formed by a pulsed current from external capacitor bank. Control of the hydrogen gas pressure was provided by an electromagnetic puffvalve. The paper describes experimental devices and results on the generated plasma parameters as function of RF frequency, antenna voltage, pulse duration and puffgas pressure. When operating at-1 kG B-field, ambient gas pressure in the range of few -10 mTorr, and 5 kV antenna voltage at resonant frequency of 150 kHz, the plasma density range was （3-7）×10^12 cm3 with a temperature of a few eV.
基金Project (No.90707002) supported by the National Natural Science Foundation of China
文摘The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) biasing.In these applications,a regulator with small volume,fewer external components and high efficiency is highly desired.This paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as well.With projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is realized.With projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control circuitry.Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.
