![]() ![]() Many DC-DC load requirements can be met by DC-DC converter ICs that include integral power switches. It is said to be "in dropout" when that happens. Similarly, a buck converter cannot provide the desired output when the input voltage is less than that output. Note that a boost DC-DC converter output will rise with input voltage when the input exceeds what has been set for the output voltage. Lastly, if the output voltage is negative, an inverting topology is used. If the input voltage ranges above and below the output voltage, a buck-boost converter or a SEPIC converter is needed. If the input voltage is less than the output voltage, choose a boost (i.e., step-up) configuration. If the input voltage is greater than the output voltage, choose a buck (i.e., step-down) topology. The desired DC-DC topology will narrow this choice. Once the initial specs of a DC-DC design are selected (e.g., input voltage range, output voltage, output current), the first step is to select a converter IC. It is the result of the author's failures and successes with scores of power-supply circuits. This article fills in information gaps for a first DC-DC power supply design. Less information is available to guide the overall design of integrated-circuit-based DC-DC converters from start to finish. Data sheets for DC-DC converters give specific formulas and some layout information. Engineering textbooks discuss control theory, loop compensation, and other highly detailed analytical methods. There are few comprehensive sources of DC-DC design information. In addition, they are sensitive to board layout and component parasitics (i.e., the characteristics of a component that are not ideal, such as resistance in a capacitor or capacitance in a MOSFET switch). Even when simplified by highly integrated ICs, they still require extensive component calculations and thoughtful selection of the controller IC. That may sound like a gloomy assessment, but it nevertheless reflects the realities of switch-mode power-supply design. Application note 2031, " DC-DC Converter Tutorial"Ī designer's first DC-DC converter circuit generally has one thing in common with first attempts in any other field: it has a slim chance of working satisfactorily when first powered.Topics include choosing the right DC-DC converter for the application MOSFET gate capacitance high switching frequencies and component size equations and calculations selecting peripheral components component placement and trade-offs grounding load and line regulation temperature sensitivity. If using this material on another site, please provide a link back to my site.This article discusses important considerations when designing a DC-DC power supply. Web site Copyright Lewis Loflin, All rights reserved. Arduino AC Power Control Using Interrupts.In Depth Look at AC Power Control with Arduino. ![]() Hardware Interrupts Demo and Tutorial for Arduino.Silicon Controlled Rectifiers Connected as Power Triacs.Silicon Controlled Rectifier Review and Circuits.Comparing Photo Triac, Photo SCR Opto-Couplers.Light Activated SCR Based Optocouplers Circuit Examples.Light Activated Silicon Controlled Rectifier (LASCR).Diac Waveform Generator, Trigger Circuits.With a microcontroller such as Arduino using a zero-crossing can control AC power to control light levels, AC motor speed, and resistive heating elements. SCRs and Triacs are used to control AC and DC power systems. Tips for the LM78XX Series Voltage Regulators.Transistor-Zener Diode Regulator Circuits.Build an Adjustable 0-34 volt power supply with the LM317.Connecting Transformers in Series-Parallel.Build Autotransformer-Variac AC and DC Power Supply.Basic Electronics Learning and Projects.Figure 4 illustrates a regulated bi-polar power supply for use with OP-AMP circuits. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |