Low Switching Noise Research Articles

A high step-up multiphase interleaved boost converter for fuel cells power system

The fuel cells need the high step-up DC/DC converter with low current ripples to interface to the high voltage DC grid. A novel zero voltage switching high step-up multiphase interleaved boost converter (ZVS HSMIBC) is proposed in this paper. This new converter employs advantages of low input current ripples, high voltage step-up ratio, soft-switching operation, and low switching harmonics and noise. In this paper, the two-phase interleaved structure of the proposed ZVS HSMIBC is analyzed and researched in detail as a representative topology. The relevant conclusions also can apply to multiphase (3 and above) interleaved structure of the HSMIBC. Finally, an experimental prototype is built and test, the experimental results show that the proposed converter can operated under ZVS conditions with low input current ripples and low switching noise and harmonics. In addition, this converter can obtain high voltage step-up ratio up to 45 (mn = 8, d = 0.8) with high efficiency, and proportion of the experimental ratios to theoretical ratios is also high (not less than 0.8).

Enhancement of turn-off gate voltage waveform change by digital gate control for bond wire lift-off detection in IGBT module

The bond wire lift-off is the one of main failures for insulated gate bipolar transistors (IGBT) power modules. The wire lift-off increases parasitic inductance LeE in the module and the gate voltage Vge waveform is modulated by LeE·dIe/dt. Therefore, the Vge waveform has the potential for an indicator of condition monitoring. The Digital gate control (DGC) can control switching behavior precisely for low-loss and low-noise switching. It is also effective for sensitivity enhancement of Vge waveform changed by the wire lift-off. This paper reports how the DGC 2-step vector control (2-sVC) can improve the wire lift-off failure detection sensitivity by Vge waveform. The experiment results showed that the Vge spike was generated by LeE·dIe/dt at the turn-off switching and the spike generation timing depended on the wire number. The DGC obtained the larger timing-shift Δtwire and the amplitude ΔVge-surge than those at the conventional gate control. In addition, the best vector condition improved the trade-off between turn-off loss and collector voltage overshoot compared with the conventional gate control. From these results, the DGC is effective to enhance the sensitivity of bond wire lift-off detection by Vge waveform maintaining the best switching performance.

A Single-Ended Transmitter With Low Switching Noise Injection and Quadrature Clock Correction Schemes for DRAM Interface

A Single-Ended Transmitter With Low Switching Noise Injection and Quadrature Clock Correction Schemes for DRAM Interface

A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests.

This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.

Pulse Retiming for Improved Switching Rates in Low-Noise Cross-Phase-Modulation-Based Fiber Switches

Temporal multiplexing or demultiplexing of quantum signals would benefit from low-loss, high speed, high rate, and low noise switches. Fiber cross-phase-modulation based switches are a promising solution, but their maximum switching rate is usually limited by pump power limitations. We demonstrate the use of mid-stage pump-pulse re-timing to improve the pump-power efficiency and thus increase the maximum switching rates of such devices. The maximum average pump pulse rate of the switch is shown to increase by more than 50% to 800 MHz when employing pump-pulse retiming. We furthermore confirm the suitability of the switch for quantum signals by sending one of a pair of quantum-correlated photons through the switch while incurring no noticeable degradation of correlations.

The Application of High Efficiency and Low Noise Switching Power Supply in Fiber Optic Gyroscope

For high-precision fiber optic gyro systems, the efficiency and noise in the switching power source limits its application and also affects the system's light source and signal processing circuit, resulting in output errors. The interference mechanism of switching power supply ripple noise on super luminescent diode (SLD) light source and demodulation module in fiber optic gyro system is analyzed. A high-efficiency and low-noise switching power supply based on synchronous rectification is proposed. The power supply uses RC circuit to realize adjustable switching frequency. The push-pull isolation topology, LC filter and LDO regulator circuit are used to achieve constant voltage output with peak-to-peak ripple noise of less than 1mV. The conversion efficiency of the switching power supply is improved by 10%, which provides a high-quality power source for the high-precision fiber optic gyroscope. In the meanwhile, the switching power source for FOG is 541cm in size, which is beneficial to the miniaturization of inertial navigation system.

A Single-Switched High-Switching-Frequency Quasi-Resonant Flyback Converter

The demand of miniaturization of power systems has accelerated the research on high-switching-frequency power converters. A single-switched quasi-resonant flyback converter that features low switching loss and low switching noise at high switching frequency is investigated in this paper. In order to realize near fully soft switching, a resonant inductor of primary side and a resonant capacitor of secondary side are utilized to recycle the transformer leakage energy and realize zero-current switching (ZCS) at turn off and valley switching (VS) at turn on of the primary switch, and ZCS at turn off of diode. The VS is utilized based on the resonance between the resonant inductor and the equivalent switch drain capacitor. In the closed-loop control, a pulse frequency modulation mode with time fluctuation of switching period is implemented to realize VS at turn on of switch and an on – off control mode is utilized to improve the overall efficiency. Low cost, low losses, and low switching noise are all realized in the proposed prototype. The proposed concept has been validated on a 1 MHz 12 V/3 A prototype with 80 V dc input. The peak efficiency is 90.3% in the on – off mode by using GaN device without synchronous rectification.

An All-Digital Low-Noise Switching DC–DC Buck Converter Based on a Multi-sampling Frequency Delta-Sigma Modulation with Enhanced Light-Load Efficiency

This paper presents an all-digital technique to control DC–DC switching buck converters for noise-sensitive low-power applications. The controller is designed based on a multi-sampling frequency digital delta-sigma modulator, whose sampling frequency is adjusted according to the load current. The proposed controller demonstrates the efficiency performance of the digital pulse-width modulation controller counterpart at heavy load while reducing output spikes by 37 dB without any additional processing. At light load, the controller scales down the switching frequency by scaling down delta-sigma modulator sampling frequency. Consequently, light-load efficiency is improved by more than 40% compared to its fixed frequency counterpart. In particular, the proposed solution adopts a unity-gain signal-transfer function delta-sigma modulator that avoids excess phase in the control loop. The proposed technique is compact, scalable and compatible with the standard digital CMOS implementation. Experimental and simulation results characterizing the proposed solution are provided.

The driver design for N2O gas detection system based on tunable interband cascade laser

In this paper, the driver circuit for N2O gas detection system based on tunable interband cascade laser (ICL) is developed. Considering the influence of power supply stability on the digital-analog hybrid drive circuit of tunable diode laser absorption spectroscopy (TDALS), the high-efficiency TPS5430 is used to design the positive and negative power supply circuit. The large electrolytic capacitor + post-stage LC filter combination filter is used to effectively filter out high and low frequency ripple and switching noise. The use of thick high current trace + via + multilayer printed circuit board (PCB) design makes the line temperature rise smaller, more stable and durable, and uses high frequency shielding inductance to effectively reduce radiation interference to ensure the stability of the drive. The STM32F407, a highperformance microcontroller based on the ARM Cortex-M4 core, is used as the master control chip and generates a sawtooth scanning signal. The direct digital synthesizer (DDS) chip ICL8038 is used to generate a sinusoidal modulated signal of a specific frequency. The two signals are superimposed by a reverse addition circuit, and the laser drive signal is generated by a developed positive feedback balanced voltagecurrent conversion circuit. Experimental results show that the driver circuit can well meet the drive development requirements of N2O gas detection systems based on tunable interband cascade laser.

A rapid and low noise switch from RANS to WMLES on curvilinear grids with compressible flow solvers

A turbulent inflow for a rapid and low noise switch from RANS to Wall-Modelled LES on curvilinear grids with compressible flow solvers is presented. It can be embedded within the computational domain in practical applications with WMLES grids around three-dimensional geometries in a flexible zonal hybrid RANS/LES modelling context. It relies on a physics-motivated combination of Zonal Detached Eddy Simulation (ZDES) as the WMLES technique together with a Dynamic Forcing method processing the fluctuations caused by a Zonal Immersed Boundary Condition describing roughness elements. The performance in generating a physically-sound turbulent flow field with the proper mean skin friction and turbulent profiles after a short relaxation length is equivalent to more common inflow methods thanks to the generation of large-scale streamwise vorticity by the roughness elements. Comparisons in a low Mach-number zero-pressure-gradient flat-plate turbulent boundary layer up to Reθ=6100 reveal that the pressure field is dominated by the spurious noise caused by the synthetic turbulence methods (Synthetic Eddy Method and White Noise injection), contrary to the new low-noise approach which may be used to obtain the low-frequency component of wall pressure and reproduce its intermittent nature. The robustness of the method is tested in the flow around a three-element airfoil with WMLES in the upper boundary layer near the trailing edge of the main element. In spite of the very short relaxation distance allowed, self-sustainable resolved turbulence is generated in the outer layer with significantly less spurious noise than with the approach involving White Noise. The ZDES grid count for this latter test case is more than two orders of magnitude lower than the Wall-Resolved LES requirement and a unique mesh is involved, which is much simpler than some multiple-mesh strategies devised for WMLES or turbulent inflow.

A High-Switching-Frequency Flyback Converter in Resonant Mode

The demand of miniaturization of power systems has accelerated the research on high-switching-frequency power converters. A flyback converter in resonant mode that features low switching losses, less transformer losses, and low switching noise at high switching frequency is investigated in this paper as an alternative to a conventional quasi-resonant (QR) flyback topology to increase power density. In order to find a compromise between magnet size, electromagnetic interference (EMI), and efficiency, the concept utilizes the resonant behavior between transformer leakage inductance and snubber capacitor to achieve near-zero-voltage switching at both turn-on and turn-off of the primary switch, low core loss due to a continuous transformer magnetizing current, and reduced EMI due to low di / dt and dv / dt values. Meanwhile, the concept uses the regenerative snubber to recycle the transformer leakage energy with two snubber diodes and one snubber capacitor. The proposed concept has been validated on a 340-kHz 65-W prototype. Compared to the conventional QR flyback converter operating at the same switching frequency, the proposed concept has 2% efficiency improvement and better EMI performance.

Single‐Stage ZVS‐PWM AC‐AC Power Converter Using All SiC Power Module for High‐Frequency Induction Heating Applications

SUMMARYThis paper presents a novel prototype of a single‐stage zero voltage soft‐switching pulse‐width modulation ‐controlled ac‐ac converter with a silicon carbide (SiC)‐MOSFET/SiC‐SBD power module for high‐frequency (HF) induction heating (IH) applications. The newly developed ac‐ac converter can achieve higher efficiency than a Si‐IGBT/Si‐PN diode power module‐based prototype due to a low ON‐resistance of SiC‐MOSFET and a low forward voltage of SiC‐SBD under the condition of HF switching. The performances of the new prototype converter are evaluated by experiment with a single‐phase IH utensil of ferromagnetic stainless metal, after which the high‐efficiency and low switching noise characteristics due to the all SiC power module are actually demonstrated.

Charge Current Controlled Single Phase Integrated Switched Mode Power factor Correction Converter

Integration of converters reduces the number of control switches and increases the power handling capacity. Charge current control have the features like fast dynamic response, design of compensator is easy and low switching noise, so this controller is applicable for power factor correction application. In this paper analysis, design and implementation of charge current controlled integrated buck flayback converter is proposed. A universal range of ac input (90-230V), 48V dc output, 100W load, 100 KHz switching frequency integrated converter is implemented using MATLAB/ Simulink software. Experimental results conform and validate the analysis.

シリコンIGBTの最新技術

IGBT as the representative of the MOS-bipolar device has widely used for power conversion system, because it has the high controllability as MOS gate device and high breakdown voltage with low ON resistance as bipolar device simultaneously. IGBT has the potential to satisfy so many requirement such as low loss, low switching noise, high breakdown voltage, low cost, high efficiency and high reliability. In this paper, we summarize recent topics of IGBT and its analysis from the above points of view.

소형 BLDC 전동기 센서리스 드라이브의 단상 역기전력과 중성점을 이용한 제어기법 연구

Brushless Direct Current(BLDC) Motor is essential to measure a rotor position because of that this motor type needs to synchronize the rotor`s position and changeover phase current instead of a brush and commutator used on the existing dc motor. Recently, many researches have studied on sensorless control drive for BLDC motor. The conventional control methods are a compensation value dq, Kalman filter, Fuzzy logic, Neurons neural network, and the like. These methods has difficulties of detecting BEMF accurately at low speed because of low BEMF voltage and switching noise. And also, the operation is long and complex. So, it is required a high-performance microprocessor. Therefore, it is not suitable for a small BLDC motor sensorless drive. This paper presents control methods suitable for economic small BLDC motor sensorless drive which are an improved design of the BEMF detection circuit, simplifying a complex algorithm and computation time reduction. The improved motor sensorless drive is verified stability and validity through being designed, manufactured and analyzed.

Development of piezoelectric transformer-coupled solid state relays for electrical circuit control in railway systems

A solid state relay (SSR) is an electrical ON–OFF control device through which the delivery of electrical power to loads is switched either ON or OFF by a small control signal. The device serves the same function as a classical electromechanical relay (EMR) but carries no mechanical switching mechanism so that it has a faster switching time, a lower switching noise, a stronger tolerance to mechanical shock and vibration, a longer lifetime, a smaller size and a lighter weight. Photo-coupled SSRs (PcSSRs) are regarded as the most popular type of SSR nowadays. However, the susceptibility of PcSSRs to power surge and lightening often requires specific protections to ensure their normal operation and performance, especially for railway systems. To advance SSR technology for an improved electrical circuit control in railway systems, we have developed a novel type of SSR, called piezoelectric transformer-coupled SSRs (PTcSSRs), by utilising the high input–output electrical isolation property of a modified Rosen-type piezoelectric transformer (PT) for coupling between the input low-voltage dc–ac control circuit and the output high-voltage ac load circuit. In this paper, we report the design, development and performance of a PTcSSR having a 12 V dc input and a 40–240 V, 2 A, 50/60 Hz ac output, and compare the measured performance data with those of a commercial PcSSR used for electrical circuit control in modern railway systems. The development of the PT and its input–output circuit is also discussed.

High Performance Computing on Fast Lock Delay Locked Loop with Low Power State and Simultanoeus Switching Noise Reduction

Problem statement: In any multimedia processor, controller may consume most of the on- chip memory resources. The memory requirement is directly depends on algorithm shared by different blocks, so leads to failure in the system models. Approach: This study presents the implementation of DLL unit used for memory optimization. Various aspects of the underlying coarse lock detector are explored and modifications are made with software r eference implementation. The whole system is implemented in 0.18 µm CMOS technology, where an input reference clock to an outgoing data clock monitors and true locking is initialized with 50% d uty cycle correction. Results: From the measurement result of DLL operation, the output clo ck jitter is analyzed. Power consumption of DLL including large size output buffer is about few mW. Conclusion: The great challenge in this implementation is communication bandwidth, has brought to process variation and power state reduction techniques. In addition, inefficiency of computing capacity and simultaneous switching noise is reduced in the real time applications.

A Two-Phase Separately Randomized Pulse Position PWM (SRP-PWM) Scheme With Low Switching Noise Characteristics Over the Entire Modulation Index

This paper describes a two-phase separately randomized pulse position pulsewidth modulation scheme that can obtain the randomization effect on the switching noise spectra over the entire modulation index ( M) range. In the proposed scheme, the zero vector is selected as V(1 1 1) when M ≥ 0.7 and as V(0 0 0) when M <; 0.7. For the validity of the proposed method, a 16-bit microcontroller SAB-C167 was used and the experiments were performed on a 1.5-kW three-phase induction motor which is coupled an eddy current brake load. The switching noise was measured in the anechoic room using a RION SA-01. Experiment results were measured at a distance of 0.15 m away from the side of induction motor. The experimental results show that the harmonic spectra spread over a wideband area, and the switching noise for all the M is reduced by the proposed method.

Design of output buffer with low switching noise and load adaptability

A new CMOS output buffer with low switching noise and load adaptability is presented in this paper. By designing an innovative combination structure of two driving stages, the buffer can reduce switching noise and output ringing with no penalty on signal transmission speed. Furthermore, the buffer can automatically adjust the total driving capability in response to variation of loading condition, the load adaptive method is simple and effective without the necessity for a feedback circuit. The proposed buffer has been designed in a TSMC 90 nm CMOS process. Simulation results demonstrate that the proposed buffer achieves 4.1---53.5% improvements in ground bounce and 2.9---15.2% reductions in output ringing compared with those of the AC/DC buffer. Meanwhile, it reduces ground bounce by 6.5---17.6% and output ringing by 3.8---10.9% relative to the CSR buffer.

Noise in boron doped amorphous/microcrystallization silicon films

Hydrogenated silicon (Si:H) film was grown by radio frequency plasma enhanced chemical vapor deposition (PECVD) method. The transition between hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon (μc-Si:H) was characterized by X-ray diffraction analysis. A semiconductor system was used to measure low frequency noise (1/ f noise) and random telegraph switching noise of Si:H films. The results show that the 1/ f noise of μc-Si:H is 4 orders of magnitude lower than that of a-Si:H and no RTS noise was found in both films. It also shows that using μc-Si:H instead of a-Si:H film as a sensing layer will enable the development of high performance uncooled microbolometer.