Table-Aided Design of the Energy-Storage Reactor in DC-to-DC Converters

A new procedure for the selection of magnetic cores for use in energy-storage dc-to-dc power converters that eliminates the need for an automated computer search algorithm and stored data file is presented. The converter configurations included in the procedure are the three commonly encountered single-winding converters for voltage stepup, for current stepup and voltage stepup/current stepup, and for the two-winding converter for voltage stepup/current stepup. For each converter configuration, three types of controllers are considered: constant-frequency, constant on-time, and constant off-time. Using concepts developed from analyses of these converters by considering the transfer of energy by means of an energystorage inductor or transformer, a special table of parameters calculated from magnetic core data is constructed, which leads to a considerably simplified design procedure.     

A State-Trajectory Control Law for DC-to-DC Converters

Mathematical representations of a state-plane switching boundary employed in a state-trajectory control law for dc-to-dc converters are derived. Several levels of approximation to the switching boundary equations are presented, together with an evaluation of the effects of nonideal operating characteristics of converter power stage components on the shape and location of the boundary and the behavior of a system controlled by it. Digital computer simulations ions of d-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance.     

Cross Noise in Multi-Output DC-to-DC Converters

In a multi-output dc-to-dc converter with cross regulation, the noise generated in one of the multiple loads is transmitted to the other loads. It is called ?cross noise.? This cross noise is analyzed and experimental results are given. High-frequency equivalent circuits, which are composed of parasitic parameters and have several parallel and series resonances, are presented for cross noise in a two-output dc-to-dc converter. The frequency responses versus 100 kHz through 10 MHz noise are calculated from these equivalent circuits and agree well with experimental results.     

State Trajectories Used to Observe and Control DC-to-DC Converters

State-plane analysis techniques are employed to study the voltage stepup energy-storage dc-to-dc converter. Within this framework, an example converter operating under the influence of a constant on-time and a constant frequency controller is examined. Qualitative insight gained through this approach is used to develop a conceptual free-running control law for the voltage stepup converter which can achieve steady-state operation in one on/off cycle of control. Digital computer simulation data are presented to illustrate and verify the theoretical discussions presented.     

DC-to-DC Converter Power-Train Optimization for Maximum Efficiency

A new way is given to describe the independent and dependent design variables of the power train of a dc-to-dc converter in terms of a multidimensional design-parameter space. These concepts provide a framework for examining the problem of design optimization of the power train, with particular emphasis on the maximization of converter efficiency. Numerous examples of important parameterspace surfaces illustrate some of the major relationships between core volume, switching frequency, and output power and between efficiency, ripple, and temperature rise of the energy-storage reactor. Also, the difference in performance between the continuous and discontinuous magnetomotive (MMF) force modes of operation is explored.     

Steady-State Characteristics of the Push-Pull DC-to-DC Converter

Six modes of operation for the push-pull 4c-to-dc converter are presented by taking into account the magnetizing current of the transformer. If the inductance of the transformer is decreased, the region where the output voltage is abnormally high is expanded in the load characteristics.     

A novel resonant converter topology for DC-to-DC power supply

A class-E DC-to-DC converter with half-wave controlled current rectifier is proposed. Its output voltage is controlled by the conduction angle of the rectifier switch at constant switching frequency. Zero voltage switching for all the switches can be maintained from full load to no load. Its steady state characteristics are analyzed and the effects of the circuit parameters are studied. Some extensions of the proposed converter are also discussed. The analysis is verified by PSPICE simulation and an experimental prototype     

Steady-state analysis of PWM DC-to-DC regulators

A new method for steady-state analysis of pulsewidth modulation (PWM) hard-switching DC-to-DC regulators is presented. The power stage and the feedback control circuit are analyzed as two interconnected blocks. The intersection of their open-loop DC steady-state characteristics with the ramp voltage provides a guess candidate steady-state solution (CS). An iterative process is used to validate it as true steady-state solution (TS) when the bias conditions of switching devices (SDs) are fulfilled everywhere in the switching period.     

A Design for Thick Film Microcircuit DC-to-DC Converter Electronics

The design concept for thick film microcircuit dc-to-dc converter electronics used in the power subsystem of the Thermoelectric Outer Planet Spacecraft is presented. Microcircuits have been used in low power logic circuits for nearly ten years, but only recently have these techniques been applied to power subsystem circuits which operate at higher power levels. Thick film microcircuit techniques have been utilized in a dc-to-dc converter reducing weight by 70 percent, volume by 80 percent, and interconnections by 75 percent. The close piece-part spacing allowed short interconnections and lower dissipation, and reduced noise coupling. The developed microcircuit handled total power levels from one watt to twenty-five watts.     

Step load response of a current-mode-controlled DC-to-DC converter

This paper analyzes the step load response of a current-mode-controlled pulsewidth modulation (PWM) converter and also presents design guidelines for obtaining a good step load response. Analytical expressions for the step load response are derived in terms of the power stage and feedback compensation parameters. Control design to minimize the overshoot and settling time of the output voltage is presented. Analysis results are verified by large-signal simulations.     

Generation and classification of PWM DC-to-DC converters

A method is presented by which generation and classification of pulsewidth-modulated (PWM) DC-to-DC converters can be effected. Fundamental blocks known as converter cells can be used to generate a plethora of converters leading to a number of useful new converter topologies. A classification of basic converters is proposed in terms of converter-cell generated families     

A General Model for Switching Converters

A low frequency, small signal model, valid for all types of converters, both in the heavy and the light mode of conduction, is developed in block diagram form. The model provides a clear insight into the behavior of such converters and enhances the respective contributions of input and output filters.     

Analysis and prediction of regulation in a multiple-outputcurrent-mode controlled DC-to-DC converter

A technique is developed for predicting the closed-loop steady state output voltage regulation of a multiple-output current-mode controlled converter. The proposed model accounts for the current loop, the voltage loop, and the integrator in the compensation scheme. This method allows tradeoffs with respect to regulation between different components or feedback configurations to be evaluated during the design of a converter. Experimental verification on a three-output current-mode controlled push-pull converter with single output voltage feedback is provided     

Start-Up Transient of a DC-to-DC Converter Powered by a Current-Limited Source

An analysis technique is presented which permits the designer to explore the start-up transient of a dc-to-dc converter when it is powered by a current-limited source. The current versus voltage characteristics of the source are superimposed upon those of the dc-to-dc converter. By noting the nature of the intersection of these curves in the voltage-current plane, we are able to predict whether or not the converter is able to start up while powering a specified load.     

耦合电感在正负输出开关电源中的应用

本文通过对正负输出电源特性的分析,阐述了耦合电感在解决正负输出电源交叉调节问题中的独特作用,并通过对耦合电感建立数学模型分析了耦合电感对正负输出电源电路性能的影响,通过对耦合电感的研究使我们掌握了实现正负输出电压稳定的开关电源设计方法,并在惯测系统配套的电源变换器中得以应用验证。     

Novel DSC-IPM for Compact Converters at Elevated Temperatures

A novel two-side cooling for integrated power modules (IPMs) for improved compactness and capability for elevated temperature operations is presented. This approach applies and improves off-the-shelf products of IPM without significantly changing original packaging and fabrication process. It can reduce a device's p-n junction-temperature rise by 20% at an equivalent load, thus increasing operating ambient temperatures, which is desirable for aircraft applications. The size and volume associated with a conventional cooling mechanism can be reduced, achieving improved compactness and power density.     

Status of Photovoltaic Solar Energy Converters

Solar cells will dominate the spacecraft power generation field into the 1970's. Power requirements have increased from the few hundred milliwatts of Vanguard I to the one kilowatt of the Orbiting Astronomical Observatory. This paper discusses the state of the art in solar cells and their modules and mountings; discusses improvements needed, and estimates the future for these devices.     

Properties of Low Precision Analog-to-Digital Converters

The problem of quantization and saturation noise introduced by the process of analog-to-digital conversion is addressed. Analog-to-digital converters (ADC) with even versus odd numbers of output states are compared. Expressions are derived and evaluated which yield the signal-to-noise ratio and the gain versus signal level input when the input signal has an assumed Gaussian probability density. The results presented should have application in all fields in which digital signal processing is performed.     

Low-Frequency Characterization of Switched dc-dc Converters

Averaging techniques are developed to represent buck, boost, and buck-boost types of switched dc-dc converters by approximate continuous models. Simple analytical expressions in terms of the circuit components are derived for the characteristic transient and frequency responses of time-average(continuous) power-stage models for use in designing and understanding the behavior of corresponding switched power stages. Novel conclusions include the dependence of effective circuit component values upon switch duty ratio and the existence of a real positive zero in certain transfer functions. Responses from analog computer simulations of the switched and averaged powerstages agree well and, in turn, confirm the analytic predictions. High-order systems can be analyzed by the averaging technique without a commensurate increase in complexity.     

高速A/D变换器的电路设计

本文介绍了用常见的中、小规模集成电路设计成高速 A/D 变换器。同时又利用了它的并行传输数字量的速度大大于它本身变换速度的特点,设计了两路在时序上采用相差半个周期来对输入模拟信号交替采样,使 A/D 变换器变换速度达到1MHz 以上。线路实验证明该设计是正确的,实验结果是理想的。并有广泛的使用价值。