Automatic Design The design process can be slow and time-consuming as you design, build — then redesign, rebuild and so on. It delays the design sequence and uses up valuable resources, time, staff, and budget, only to often results in an “acceptable” error amp for your system. This white paper introduces a solution to inefficient trial and error methods of designing.
Current Mode Control Current mode control is one of the significant topologies in power electronics. This white paper details the principle of current mode control, how it is supposed to work, what topologies come closest to truly representing the concept, and how to test a current mode converter to see if it is actually working as advertised.
New Signal Injection Technique New power supply designs are making it harder to measure for gain and phase margin. This measurement is important because step load testing does not measure critical parameters such as conditional stability. A new technique has been developed which can be implemented on virtually any PWM chip. This white paper describes this technique and gives examples of how to apply it to various types of integrated circuits.
New Techniques for Loop Stability Testing in Power Factor Correction Circuit Stability testing is important because loop bandwidth and stability affect how fast the circuit will respond to source voltage transients and load changes. Power factor correction circuits often have two feedback loops, and both loops can have stability problems,. This white paper describes how to test the feedback loops in power factor correction (PFC) chips for stability.
New Techniques for Measuring Feedback Loop Transfer Functions in Current Mode Converters In power supplies with current mode control topology, the current feedback forms an internal digital loop that cannot be directly measured. The phase margin of this loop is a function of duty cycle, and this loop can become unstable for duty cycles over than fifty percent. Although techniques such as slope compensation can be used to adjust the stability of this internal feedback loop, measurement of this loop is essential to verify the effectiveness of the adjustment. Download this white paper for new best-practices in measuring feedback loop transfer function.
Optimum Feedback Amplifier Design for Control Systems Optimizing the performance of a feedback control loop can be done with techniques that are simple, effective, and easy to apply. In this white paper, we will discuss best practices for optimizing your single to multiple loop systems.
Practical Testing Techniques for Modern Control Loops New power supply designs are becoming harder to measure for gain and phase margin, which is important because step load testing does not measure critical parameters such as conditional stability. A new technique has been developed which doesn't have limitations and can be implemented on virtually any PWM chip. Learn more by downloading our white paper that describes best practices for testing modern control loops.
Relating Converter Transient Response Characteristics to Feedback Control Loop Design Confusion often surrounds the fundamental relationships of time and frequency domains as they pertain to the design of the feedback control portions of power supplies. The purpose of this paper is to demonstrate the relationships between loop gain crossover frequency, phase margin, and transient response so that the design engineer can achieve the best possible dynamic performance from a given power supply.
Specify Gain and Phase Margins on All Your Loops When purchasing a power supply, you should specify the gain and phase margins of all feedback loops within a power supply. The main loop should be specified for stability margins not only as shipped with local sense, but with remote sense and extra output capacitance too. Your specifications should also include regulated and the margins of the current limit loops if the supply has active current limiting. Learn more about developing specifications for your gain and phase margins by downloading this white paper.
Stability Testing of Multi-Loop Converters Measurement of loop gain and loop phase shift versus frequency is generally possible with single output power supplies or multiple output supplies where each output is independently regulated to determine the phase and gain margins and insure stability of the feedback loop. Measurement requires access to a point where the loop is confined to a single path; such a point does not exist in many low-cost computer power supplies which constitute the majority manufactured today. Download this white paper to learn techniques for overcoming this obstacle and obtaining loop data even where a single signal path is not accessible.
Testing Power Factor Correction Circuits for Stability Power factor correction has become an increasingly necessary feature in new power supply designs. In a power factor correction circuit, there are two feedback control loops; one loop that is fast and a second loop, which is much slower. Testing the slow loop for stability is easy with the proper equipment, but testing the faster loop is much more difficult. Download this white paper to learn tips and techniques necessary to measure the stability of each of these loops and specifies necessary equipment and procedures to perform these tests.
Testing and Stabilizing Feedback Loops in Today's Power Supplies Feedback loops aren't what they used to be. Gone are the days of a single feedback path, an external or discreet error amplifier, a direct connection from output to input, and the days of voltage mode control, even though it is a better choice in some applications. The majority of power supplies manufactured today throughout the world use a similar topology. Learn more by downloading our white paper that details practical tips in dealing with the problems made by modern topologies.
The K Factor: New Mathematical Tool Analysis of the stability of feedback loops has always been a subject shrouded in mystery and confusion. Recent efforts to clear away some of these problems have helped, but even with computer-aided design, a certain amount of trial-and-error remained. This paper presents a new mathematical concept that is simple but powerful. The techniques described allow synthesis of a feedback amplifier with a few algebraic equations to obtain any desired crossover frequency and phase margin (within reason) on the first try.
Current Mode Control Current mode control is one of the significant topologies in power electronics. This white paper details the principle of current mode control, how it is supposed to work, what topologies come closest to truly representing the concept, and how to test a current mode converter to see if it is actually working as advertised.
New Techniques for Measuring Feedback Loop Transfer Functions in Current Mode Converters In power supplies with current mode control topology, the current feedback forms an internal digital loop that cannot be directly measured. The phase margin of this loop is a function of duty cycle, and this loop can become unstable for duty cycles over than fifty percent. Although techniques such as slope compensation can be used to adjust the stability of this internal feedback loop, measurement of this loop is essential to verify the effectiveness of the adjustment. Download this white paper for new best-practices in measuring feedback loop transfer function.
Optimum Feedback Amplifier Design for Control Systems Optimizing the performance of a feedback control loop can be done with techniques that are simple, effective, and easy to apply. In this white paper, we will discuss best practices for optimizing your single to multiple loop systems.
Specify Gain and Phase Margins on All Your Loops When purchasing a power supply, you should specify the gain and phase margins of all feedback loops within a power supply. The main loop should be specified for stability margins not only as shipped with local sense, but with remote sense and extra output capacitance too. Your specifications should also include regulated and the margins of the current limit loops if the supply has active current limiting. Learn more about developing specifications for your gain and phase margins by downloading this white paper
Stability Testing of Multi-Loop Converters Measurement of loop gain and loop phase shift versus frequency is generally possible with single output power supplies or multiple output supplies where each output is independently regulated to determine the phase and gain margins and insure stability of the feedback loop. Measurement requires access to a point where the loop is confined to a single path; such a point does not exist in many low-cost computer power supplies which constitute the majority manufactured today. Download this white paper to learn techniques for overcoming this obstacle and obtaining loop data even where a single signal path is not accessible.
Using CAE/CAT Tools to Evaluate Power Supply Parasitics Parasitic elements do not show up on the schematic or parts list! Even though much attention has been focused recently on modeling of power supply circuits, that one major drawback has greatly diminished modeling success and effectiveness. This white paper describes the application of computer-aided engineering and test equipment, which can identify and quantify these elements.
LP Distributed Power Rev Distributed power systems can oscillate, especially when driving one power supply with another power supply. The input and output impedances of a power supply can predict this oscillation. Download this white paper to learn what causes distributed power systems to oscillate and how you can prevent oscillation.
Minimizing Input Filter Requirements in Military Power Supply Design Due to MIL- STD-461, military power supplies are frequently put through susceptibility testing. Susceptibility testing consists of treating the power supply as a filter, and measuring the attenuation of input signals as a function of frequency. This white paper describes the relationship between open-loop gain of the voltage feedback loop and input filter characteristics.
New Techniques for Loop Stability Testing in Power Factor Correction Circuit Stability testing is important because loop bandwidth and stability affect how fast the circuit will respond to source voltage transients and load changes. Power factor correction circuits often have two feedback loops, and both loops can have stability problems,. This white paper describes how to test the feedback loops in power factor correction (PFC) chips for stability.
Source-Load Interactions in Multi-Unit Power Systems Switching regulators have negative input impedance, at least at low frequency. Before switching regulators came into such widespread use, they were mainly stand-alone units operating from a low source impedance and driving a passive load. Now, there are many instances where switching regulators serve as both source and load. This white paper discusses various criteria that have been developed to assure stability under these new conditions and gives practical suggestions of design and testing criteria to assure stability under all operating conditions.
Testing Power Factor Correction Circuits for Stability Power factor correction has become an increasingly necessary feature in new power supply designs. In a power factor correction circuit, there are two feedback control loops; one loop that is fast and a second loop, which is much slower. Testing the slow loop for stability is easy with the proper equipment, but testing the faster loop is much more difficult. Download this white paper to learn tips and techniques necessary to measure the stability of each of these loops and specifies necessary equipment and procedures to perform these tests.
Testing Power Sources for Stability Recent advances in measurement technology have made it quick and easy to measure stability margins. On power sources with remote voltage sensing terminals, gain and phase margins can usually be determined in a few seconds without even removing the cover; these measurements can be made while the source is operating normally. Download this white paper to learn how to test power sources for stability.
Oh By The Way - We Need A Power Supply Integrating power supply into a new system is often left until late in the design cycle. The problems encountered in choosing and mating a power supply with a nearly completed system can seem overwhelming, particularly with the constraints imposed by overall system requirements and development schedules. Learn how to pick a power supply so you can avoid problems in the late phase of a project by downloading this white paper.
Using CAE/CAT Tools to Evaluate Power Supply Parasitics Parasitic elements do not show up on the schematic or parts list! Even though much attention has been focused recently on modeling of power supply circuits, that one major drawback has greatly diminished modeling success and effectiveness. This white paper describes the application of computer-aided engineering and test equipment, which can identify and quantify these elements.
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Venable provides scalable energy storage and power systems test solutions for precise voltage, current, and frequency measurements, partnering with engineers to ensure battery and power systems around the world will meet stringent field performance demands.
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