DC-DC Power Supplies Research Articles

Design of A 12-phase Clock Generator Based on DLL

Abstract This article proposes a 12-phase clock generator for DC-DC power supply chips, which can be used for external clock synchronization of DC-DC and serves as the foundation for multiple parallel connections of DC-DC. This article is based on the NTC 0.35 um BCD process and verified through simulation by using Cadence software. In typical environments of 3.3 V and 27°, the clock input range is 832 K-49.6 MHz, the time to reach stability is less than 5 us, the clock jitter is less than 1%, the duty cycle error is less than 3.5%, and the phase error generated is less than 1%.

Portable X/g-ray survey meter based on the internet of things network for measuring the environmental radiation distribution

Real-time detection of X/gamma radiation dose rates holds particular significance in nuclear science research. In this study, we developed a portable X/gamma-ray survey meter for large-scale distributed real-time monitoring of ambient dose equivalent rates in the surrounding environment. This innovative device uses a silicon photomultiplier coupled with a CsI(Tl) scintillator and can connect to an Internet of Things network. Additionally, it facilitates a wide spectrum of dose rate measurements by modifying the frequency of a pulse-frequency modulation-type DC-DC power supply mode. The energy response of the survey meter, which is improved through Geant4 simulations and a multi-comparator design, ranges from 48 keV to 1.3 MeV, encompassing various common protection level applications. It effectively measures gamma radiation dose rates ranging between 0.1 mSvh-1 and 100 mSvh-1 for 60Co. Temperature compensation of the detector was achieved through a series of experiments. The meter exhibits a deviation of -25 % to +25 % at temperatures between -40?C and +40?C.

Efficient Hybrid Dual Full-Bridge DC–DC Converters for Pulsed Output Current Applications

This paper presents a hybrid full-bridge DC-DC converter for a wide output voltage range in high efficiency, especially for pulsed output current applications. For the conventional phase-shift-full-bridge DC-DC converter, the hard switching and circulating current lower the efficiency in the wide output conversion ratio. To improve the efficiency of the DC-DC power supply for the pulsed output current, a hybrid DC-DC converter is proposed. On the primary side, two full bridges are integrated by sharing a bridge leg. The circuit on the secondary side is a hybrid rectifier stage. For the pulsed output current with a constant load resistor, a single full bridge works in the low output current. For the large output current, the hybrid two full bridges work together. The circulating current in the hybrid working mode is reduced by a blocking capacitor. The converter is controlled by the phase shift and duty cycle control. All the switches work in zero voltage switching. A prototype is built to verify the performance and control strategy of the converter.

A Bootstrap Drive and Level Shifting Method for Buck-boost Converter with NMOS as the Main Switch Transistor

In the design of DC-DC power supply, compared with a P-type metal oxide semiconductor field effect transistor (PMOS) with the same width-to-length ratio, N-type metal oxide semiconductor field effect transistor (NMOS) as the main switching transistor greatly reduces the on-off loss and improves the conversion efficiency of the system. This article introduces a gate voltage bootstrap and level shifter circuit for a Buck-Boost DC-DC converter with NMOS main switching transistor. The drive voltage between the gate and the source pole of the main switch transistor can be stabilized, which is independent of the switch junction voltage (V SW) and solves the problem that the drive voltage of the gate is too high or too low due to the influence of the bootstrap voltage in the traditional structure. Based on the 0.18 μm BCD process, the circuit design and physical implementation of the proposed method are verified. The test results show that the bootstrap drive circuit functions normally and the bootstrap drive voltage is about 5 V when the input voltage is 2.9~4.5 V and the output voltage is −2~-5 V. In addition, the proposed gate-level shifting circuit can reduce the drive delay of the main switch transistor to less than 12 ns.

An Input Up to 100-V High Voltage LDO Based a Novel Pre-Regulation and a Simple Clamp Current Circuit

With the aim of improving the small input voltage range and complex structure of the current-limiting circuit in the traditional LDO, a wide-range high-voltage input LDO was designed, which uses a pre-regulation principle and a diode current-limiting protection scheme. Based on the DB HiTek 0.18 μm BCD process model for circuit simulation, the simulation results showed that this proposed LDO can stably output 7.6 V under the input voltage range from 13 V to 100 V. In addition, the load regulation rate was 0.0256 mV/mA, and the line regulation rate was 0.035 mV/V. When the load current exceeded 30 mA, the output voltage was prohibited and overcurrent protection was performed. The measurement results showed that the maximum input voltage of the designed chip could reach 140 V. When the load current exceeded 19 mA, the LDO had no output voltage, which indicates that the current limiting circuit can work stably. The circuit designed in this paper has a simple structure but good stability. To date, the LDO has been applied to other DC-DC power supply chips.

Research on DC-DC power health management technology based on degradation test and deep learning

The health state of DC-DC power supply is the key factor to determine whether the electronic equipment can operate normally. The failure and deterioration of the power supply system will lead to the collapse of the entire electronic system. The research in this paper is based on the long-term high temperature degradation test data of a certain type of DC-DC power supply. The degradation law of power supply is studied by data preprocessing and noise reduction of sensitive parameters such as input current, output current, input voltage and output voltage. On this basis, we use the method of deep learning to model the efficiency of power supply in the process of degradation test. The experimental results show that the efficiency time series modeling of power supply degradation using LSTM method can effectively reflect the law of power supply efficiency degradation. Based on the DC-DC power health management technology combining degradation test and deep learning, the advanced fault prediction model is used to reflect the change law of power supply in the real degradation process. This method has certain theoretical and engineering value for power PHM modeling and application.

Methods of ensuring the operational stability of dc-dc power supply in arctic conditions

THEPURPOSE.To consider the features of development and exploitation of DC-DC power supplies for Arctic conditions, to show the key problems and existing methods of solving them, to identify prospective directions in the design of this type of devices.METODS.Theworkismainlyanover-viewwiththequestionsofconstruction,circuitdesign,controlprinciples,maintainingthermalequilibrium,choosingofelectricelementsandminiaturization.Thefirstpartofthearticleisdevotedtothereviewofscientificpublicationsandpatents,in the second part the idea of using a parallel architecture in frost-resistant power supplies is considered, giving an opportunity to adapt modular principle of device construction.RESULTS.Thearticleexaminestheissuesofadaptingthemodularapproachtothespecificsoffrost-resistantpowersupplies.Inthiswayyoucanbuilda self-healing, configurable, easy-to-repair power supply of wide application. With modular construction principle the entire electrical complex consists of parallel-connected cells, placed in one hermetic and heated case (a case with connectors on the surface, as well as the control and display units).CONCLUSION. Parallelconnectionofthecellsallowstoprovidea significant power reserve in the power supply, to perform a quick replacement of faulty modules without interrupting the power supply process, to increase/reduce the system power easily by changing the number of working cells. The system acquires special advantages, if the output voltage levels of the cells are adjustable. In this case, it is possible to build a universal configurable power supply of wide application,whichisa novelty on the market. If you group the cells on the output, you can use one power supply for several different consumers. The spare parts for the power supply are as simple as possible and consists of ready-made cells and connecting wires. The obtained results can be used in development of fault-tolerant secondary DC-DC power supplies for hard operating conditions.

Improving the Reliability of DC-DC Power Supply by Reserving Feedback Signals

The paper deals with the problem of improving the reliability of DC-DC power supplies with pulse-width modulation. The topicality of the work is related to the importance of power supply issues in modern electronics, since the quality of operation of consumer electrical appliances, including critical ones, directly depends on the serviceability of sources. The object of the study is feedback circuits aimed at stabilization of the parameters of power supply of consumers. Failures of the mentioned feedback circuits most often occurs due to the electronic components degradation under harsh operating conditions as well as under severe mechanical overloads. Such failures are dangerous for uncontrolled increase of power supply output voltage and output current. To avoid this, a new method of reserving voltage feedback signals is presented in the paper which is implemented on the basis of flyback supply topology. Feedback signals are formed from the optocoupler located on the load side and from the auxiliary winding of the power transformer, together forming two independent output voltage control circuits. Only one circuit performs stabilization at any given moment of time. If one of these circuits fails, the second one can simply replace it in its operation. The proposed method does not require any digital signal processing algorithms or microprocessor control modules and can be implemented on the basis of cheap, widely available analog chips that perform pulse-width control of the output voltage. As a result, the problem of sudden feedback loop failure is solved and the reliability of electrical equipment is increased. The validity of the proposed method is confirmed by the results of computer simulation with the use of MatLab-Simulink environment. The obtained results can be used in design of fault-tolerant secondary power supplies that operate in harsh operating conditions.

Engineering application research on reliability prediction of the combined DC-DC power supply

The combined DC-DC power supply is widely used in communication, aerospace and other fields because of its low power consumption, high efficiency, small volume, high reliability, modularization and so on. As the core component of power electronic system, its reliability prediction research has far-reaching practical significance. In this paper, the engineering application of reliability prediction is studied based on a combined DC-DC power supply of 17.2 kW. The prediction of the basic reliability based on “life profile” and the mission reliability based on “mission-profile” are studied. The block diagrams of basic reliability and mission reliability are established, respectively. The MTBF is 31,699 h, which is more than three times of the required value of the power supply. The reliability of the power supply for 1 h can reach 99.999%. The reliability prediction of the two aspects has practical guiding significance for the reliability distribution and reliability growth of the project, and can also be used as reference for the reliability work of other projects.

Research on switching loss reduction technology for missileborne DC-DC power supply

With the development of power electronics technology, DC-DC power supply is widely used in secondary power supply system on missile. How to restrain the loss caused by the periodical on-off of the switch tube plays an important role in ensuring the normal operation of the missile-borne power supply system. In this paper, the switching-tube Absorption Circuit and ZCT PWM soft-switching circuit are taken as the research objects, and the effects of the two circuits on the switching-tube loss suppression in the dual-pulse-width modulation mode are analysed, and a more effective method to reduce the switching loss of high frequency DC-DC power supply is obtained, it provides a reference for the further research of switching loss reduction technology in high frequency DC-DC power supply.

Improved Numerical-Analytical Thermal Modeling Method of the PCB With Considering Radiation Heat Transfer and Calculation of Components’ Temperature

The previous work relating to the numerical-analytical coupling method for steady-state thermal analysis of the laminated PCB structure is first briefly reviewed. The Fourier-series analytical solution of temperature and the finite volume method were linked together for thermally modeling the PCB. For further modeling the PCB with components, thermal-resistance parameters of the components are then used for correlating components’ temperatures with the variable arrays in the coupling equations. For further considering radiation heat transfer between the PCB and the ambient, an iterative method is proposed. The radiation-equivalent heat transfer coefficient for each surface cell and each component can be updated during the iteration. Moreover, for improving the efficiency, the multigrid strategy is integrated in the coupling method for generating discrete cells of three levels in the metal layer and PCB surface region. To testify the iterative method, the model of a simple one-layer structure is compared with that built in COMSOL Multiphysics. The modeling results of the PCB of a phantom DC-DC power supply under radiation heat transfer are also given and discussed, and the modeling accuracy is approximately derived based on Richardson’s extrapolation.

Real-Time Investigation of an Adaptive Fuzzy Synergetic Controller for a DC-DC Buck Converter

In this paper, an adaptive fuzzy synergetic controller (AFSC) for a DC-DC converter is introduced. Two robust control techniques, synergetic control combined with fuzzy logic control, are utilized to produce a reliable DC-DC power supply. This is-realized by an indirect adaptive control of a DC-DC buck converter. To further enhance robustness, a nonlinear constraint, the equivalent of the sliding surface, is used to guarantee performance and stability for any operating condition. To ensure overall strength, closed-loop signals are bounded and the stability is guaranteed using the Lyapunov theory. Control parameters are optimized using a PSO algorithm to further enhance performances. The proposed controller (AFSC) is designed through a dSpace based experimental setup to provide robust DC-DC buck converter voltage control.

Fixed Switching Frequency Digital Sliding-Mode Control of DC-DC Power Supplies Loaded by Constant Power Loads with Inrush Current Limitation Capability

This paper proposes a digital sliding-mode controller for a DC-DC boost converter under constant power-loading conditions. The controller has been designed in two steps: the first step is to reach the sliding-mode regime while ensuring inrush current limiting; and the second one is to move the system to the desired operating point. By imposing sliding-mode regime, the equivalent control and the discrete-time large-signal dynamic model of this system are derived. The analysis shows that unlike with a resistive load, the boost converter under a fixed-frequency digital sliding-mode current control with external voltage loop open and loaded by a constant power load, is unstable. Furthermore, as with a resistive load, the system presents a right-half plane zero in the control-to-output transfer function. After that, an outer controller is designed in the z-domain for system stabilization and output voltage regulation. The results show that the system exhibits good performance in startup in terms of inrush current limiting and in transient response due to load and input voltage disturbances. Numerical simulations from a detailed switched model are in good agreement with the theoretical predictions. An experimental prototype is implemented to verify the mathematical analysis and the numerical simulation, which results in a perfect agreement in small-signal and steady-state behavior but also in a small discrepancy in the current limitation due a small propagation delay. Some efficient solutions have been proposed to mitigate the inrush current in the experimental results.

Closed loop control analysis of half-bridge 1] resonant converter based battery charger

Series Resonant Converters (SRC) popularly known as Line Level Controlled (LLC) converters are the most suitable topology of DC-DC power supply. The closed loop voltage regulation of a Half-Bridge (HB) Line-Level-Controlled (LLC) converter using PI controller is presented in this paper. Major objective of PI controller is to modulate frequency and duty ratio of gate signals. A voltage controlled oscillator (VCO) is generating the gating signals which will drive the MOSFETs for getting a regulated output voltage. The optimum LLC switching frequency ranges are derived so that converter can operate at higher efficiency. In this converter the primary switches (MOSFET) are operated with Zero Voltage Switching (ZVS) and secondary switches (Diodes) with Zero Current Switching (ZCS) to have lower losses and hence to obtain higher efficiency. Finally the theoretical results are verified by simulating the converter in MATLAB1/SimulinkTM circuit Simulator. The results obtained from simulation clearly signify the controller performance for adjustment of output voltage in case of variation in input line voltage and output current through the load. If the above observations are looked closely then it clearly indicates that the controller is executing the functions of regulating the output voltage. Whenever there is any variations in input line and output load then the output voltage across the load is able to follow the reference signal.

A PWM DC-DC converter with optimum segmented output stage and current detector

High efficiency is very important for DC-DC power supplies in portable applications. A PWM DC-DC converter with optimum segmented output stage is proposed in this paper whose efficiency at light load is improved. The segmented output stage is optimally divided into 5 small segments plus 4 big segments. The segmented number of the output stage can be adaptively regulated according to the load current. Moreover, two current detector circuits are simultaneously adopted to form a mixed load current sensor in the converter to improve the detecting accuracy. A segmented current SenseFET (SCS) is used to sense the load current in continuous current mode, and a time digital converter with digital judgement (TDC-D) is designed to detect the load current in discontinuous current mode. The structure of the proposed PWM converter with optimum segmented output stage and mixed load current detector circuits is described in this paper, which has been implemented in a 0.13μm CMOS process. Simulation and testing results show that the output stages of the PWM converter can self transit from one segment stage to another segment stage according to the load condition. And the maximum efficiency improvement of the proposed converter can reach 15%.

Optimal design of line level control resonant converters in plug‐in hybrid electric vehicle battery chargers

The series-parallel resonant converter (also called line level control (LLC) resonant converter) is one of the most suitable topologies for dc-dc power supply. This study introduces the LLC resonant converter into the on-board battery chargers for the plug-in hybrid electric vehicle (PHEV) applications. Different from the previous literature which has focused on the wide operation range and hold-up time requirement in the LLC design, this study is mainly focused on battery load characteristics and its impact on the charger design. First, to guarantee high efficiency in the light-load condition in the constant voltage charging stage, the optimum LLC switching frequency range is derived. Second, considering the constant current charging function in the battery charger, the impact of peak load current on the LLC converter is discussed. The boundary between zero-voltage switching (ZVS) and zero-current switching (ZCS) in the constant current charging application is analysed. The trade-off among the minimum load voltage, maximum charge current and resonant capacitor is studied in detail. Finally, the optimal design method for the LLC resonant converter used in the PHEV battery charger is proposed. The proposed methods are validated through experiments on a 400 V/6 kW PHEV charger system with 97% efficiency.

Advanced Low-Voltage Power MOSFET Technology for Power Supply in Package Applications

In this paper, a high-current dc-dc power supply in package is reported with an emphasis on the design aspects of the low- and high-side power MOSFETs embedded in the power module. A new NexFET structure with its source electrode on the bottom side of the die (source down) is designed to enable an innovative stacked-die PSiP technology with significantly reduced parasitic inductance and package footprint. A gate voltage pulldown circuitry monolithically integrated in the low-side NexFET is introduced to effectively prevent shoot-through faults even when a very low gate threshold voltage is used to reduce conduction and body diode reverse-recovery-related power losses. In addition, an asymmetric gate resistor circuitry is monolithically integrated in the high-side NexFET to minimize voltage ringing at the switch node. With all these novel device technology improvements, the new power supply in package module delivers a significant improvement in efficiency and offers an excellent solution for future high-frequency, high-current-density dc-dc converters.

Compact DC-DC Power Design in Half-Bridge IGBT Driver

The integrated half-bridge IGBT driver need compact, high efficiency and high power density isolated DC-DC power supply, a set of two magnetic cores share a high-frequency full-bridge switches are designed. A simple circuit generates four channel drive signals, without isolation, to achieve compact on-board power supply and the best combination with the integrated half-bridge IGBT driver. The key signals are simulated, and experimental results show that the power supply is simple, reliable.

Robust Digital Control of DC-DC Power Supply with Remote Sensing

If the lines which connect the output terminal of a DCDC converter and the load are long, the voltage actually crossing to the load will change greatly due to the impedances of the lines, producing drops in voltage. In this paper, a separate terminal apart from the output terminal of DC-DC converter senses the voltage across to the load, and it leads it to the load. As a result, the voltage across to the load is adjusted so that it does not experience large changes. This method is called remote sensing. When the lines become long, the usual method of adjusting the voltage across to the load cannot sufficiently suppress changes in it. In this paper, a robust digital controller to suppress the change in the voltage across the load is proposed. Experimental studies using DSP demonstrate that this type of digital controller successfully suppresses it.

New high-frequency linked half-bridge soft-switching PWM DC–DC converter with input DC rail side active edge resonant snubbers

This study presents a new circuit topology of the active edge resonant snubber-assisted half-bridge soft-switching PWM inverter-type DC-DC high-power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high-frequency PWM inverter with a high-frequency planar transformer link in addition to input DC busline side power semi-conductor switching devices for the PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve zero current switching (ZCS) turn-on and zero voltage switching (ZVS) turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high-switching-frequency isolated gate bipolar transistor (IGBT) can be actually selected in the frequency range of 60-kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of the new converter topology is proved for low-voltage and large-current DC-DC power supplies as DC bus feeding from a practical point of view.