Questions tagged [buck]
A non-isolated DC-DC converter topology which outputs a voltage less than or equal to the input voltage.
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Low side N-Mosfet buck converter
I often see schematics of basic buck converters. The majority of these schematics use a P-MOSFET as high side switch.
Why is this design preferred over a low side, N-MOSFET buck converter?
simulate ...
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How to sketch the Bode diagram of the output filter of a Buck converter?
I'm trying to figure out the Bode diagram of the output filter of a Buck converter:
simulate this circuit – Schematic created using CircuitLab
Vout is ...
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Problem with Bode diagram in LTspice
I am working on a buck converter and I want to obtain the Bode diagrams of the open-loop circuit. The below circuit is what I made. However, the DC-gain is -96 dB while it should be very small around -...
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Is this a viable mini wind turbine setup?
I'm going to build my first wind turbine. I have already constructed the prop, 5 blades 50cm long from PVC pipes. I've searched for a decent sized motor and charge controller. The turbine will be ...
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Snubbing DCM (nonsynchronous) Buck converter
FINAL UPDATE:
I've posted an outcome report below. I'm very satisfied with how this has come out and I learned a lot in the process. More details and before/after shots in the answer below. Thanks to ...
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Buck converters- No Load condition
How exactly do buck converters work under no load condition?
The capacitor voltage will try to charge up to the peak input voltage, with no load connected across it to discharge. How to avoid this ...
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Relationship between switching frequency and controller's crossover frequency in buck SMPS
Context: tuning the control loop of a buck SMPS. I specicifally have a TI TPS40200-based circuit in mind, but I think this applies to SMPS design in general.
Quoting from Type 2 compensation network:
...
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Changing output voltage of a buck converter by electronically swapping the feedback resistors
I am going to design a circuit which is going to output some digital signals. The output stage of the circuit will have some level shifters. The level shifters will give flexibility to the user to ...
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Is there a good topology for splitting a DC power supply from a few LM2576 and LM2577?
So, this isn't the most serious project, more of a toy/hack, but I have a some LM2576 and LM2577 and I wanted to see if I could somehow get an adjustable dual rail (bipolar) supply out of them, for ...
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Multiple Input supply switching
I'm looking into designing a power supply for an RPi that can take both USB and battery at the same time, but only pull power from one of the sources. I'm not quite sure how to go about it, I was ...
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Is it ok to connect the output of buck regulator in parallel?
I am using MCP16322 buck regulator powered from 12V and outputs 5V and 2A. Is it ok to connect the output of two of these in parallel? Does connecting the outputs in parallel mess up the maximum ...
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Calculating size of cap & inductor for buck convertor
What is the idea of choosing inductor & capacitor value for buck DCDC convertors (no specific part number, in general)?
I've tried random one with low resistance, and it kinda works, but want to ...
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MOSFET failure in a high power AC-DC SMPS buck converter
I've made a AC-DC step down buck converter that converts 220 VAC to a variable 45 to 70 VDC at 5 to 10 A to charge a Li-Ion battery. I'm currently using ESP32 to drive a MOSFET driver (IR2110) to ...
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Is this normal Buck Regulator behaviour?
I recently got around to trying out buck regulators, my results weren't what I was expecting though. For one the ripple voltage seems a little high to me, It's about 800mV with no load and goes up to ...
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Can there be "too much" capacitance on a buck regulator output?
I've an MPM3610 buck regulator module with an integrated inductor of 0.47 µH and a fixed internal compensation. It employs constant-on-time regulation. The datasheet gives some application ...
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Idea behind current mode control in DC-DC converter
I am learning about control strategies for DC-DC converters.
While I find voltage mode control easy to understand, I struggle to understand
current mode control.
Is the idea here to control the ...
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Is it possible to control a DC/DC buck converter's output voltage with the DAC of an ESP32?
I came across this question here:
MCU 'remote control' of DC-DC converter's Vout adjustment potentiometer
It is about controlling the output voltage of a DC/DC buck converter by injecting voltage into ...
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Peer Review of Buck Converter
The only limitations I can think of are:
Comparator/Schmitt not gate output swing time, and
Transistor switching time
simulate this circuit – Schematic created using CircuitLab
BTW, these are ...
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Input filter transfer function derivation
In the figure above, I am trying to design an input filter that attenuates all switching frequency harmonics from i_sys, such that i_batt is a DC current with vary small ripples.
My approach is to get ...
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Input filter to reduce conducted emissions caused by DC/DC converter
This material from ROHM explains the input filter design for a DC/DC converter.
The filter circuit is given below.
I understood the design of Lf, Cf2, Cd and Rd.
If you see the 3rd page (design of ...
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Conducted EMI of buck converter is too low even without filter
I have simulated a 48 V to 12 V buck converter with LISN in LTspice. However, CM and DM EMI is way below CISPR limits. I want to simulate a real world converter. How can EMI be increased?
[2]
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Why do buck (step-down) switching regulators require an inductor and diode?
So, I understand, at least at a basic level, the method of operation of switching converters, both buck and boost. What puzzles me, though, is why buck converters in particular aren't simpler.
Why ...
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Why did my DC/DC Buck Circuit fail?
I'm in the process of debugging a PCB I made. On this board, a 24V input feeds through a DC/DC buck circuit (based around the TI TPS54202DDC) to output 11V, then an LDO to output 9V (to ensure a very ...
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How does LTSpice model reverse recovery time?
Hello everyone,
I am working on the prediction of the reverse recovery losses in a Buck converter. I have the following schematic:
You can see below a zoom on the turning-off time of the diode:
I ...
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Critique my SMPS buck design
I'm using an LM2734 buck regulator to get +3.3V at 400mA. The datasheet is unclear on how to lay out the supply, so I tried to follow some common sense, keeping all power traces short where possible. ...
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Is it possible to get a high efficiency buck-boost converter by switching between the two?
Many buck-boost converters work by boosting to an intermediate voltage, then bucking to the desired voltage. What if instead, it had a separate buck and boost section in parallel, and switched between ...
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Vin: 2-36, Vout: 4.2. Should I use step-up, followed by step-down, or SEPIC?
My application has a small device, which draws about a watt, and is powered through a small dynamo, backed by a battery:
The dynamo generates 33 volts at maximum speed, close to L6902's max input ...
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How to reduce MOSFET heating in Buck Converter
I have designed this Buck Converter which convert 60VDC to 12VDC at 10A.
Switching Freq 100KHz.
Facing MOSFET too much heating issue.
MOSFET ON time and OFF time is decided by a UC3845B based circuit. ...
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Buck Converter dies unpredictably upon connecting power
I made a PCB for an ESP32-based solenoid controller that is powered by a 24V DC Jack. I'm using an AP63205 Buck Converter to step that input down to 5V DC, and then a linear 3V3 LDO to power the ESP32....
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USB-C Power Delivery with a buck converter
Following on from my previous question: The project I'm designing requires a peak current of 5V @ 6A. The average current draw will be more like 2A.
The reason I'm looking into USB-C is that I want ...
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Buck converter operation
I have been reading about the buck converter and have also referred to the various online resources like here.
In the above circuit, as I understand, when the switch closes, current starts to ...
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Can a synchronous regulator "chirp" in burst mode?
I'm looking at (the millions of) buck regulators available for a project where the board will be a host board for a Gumstix Dual Cortex A9. This can pull quite a bit of current at maximum so I was ...
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Why 2 diodes in parallel buck converter design?
I have been looking up dc-dc buck converter designs and have question regarding the diodes.
It says "5A High current Schottky diode" is it common in buck converter design to parallel ...
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Equation 20.16 Proof
In studying the Fundamentals of power electronics by Robert Erickson I do not understand how they arrived at the equations for current and voltage
Link to Book, page 772 is where I am at
https://...
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NMOS high-side switch for buck converter
I am studying a buck converter using an NMOS for the high-side switching.
The inverter is supplied by a 3.7 V battery and should power a 0.6 Ω load. The switching is done by a 100 kHz 0-3.3 V PWM ...
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Reason fo use or not use a microcontroller to drive a buck DC/DC regulated converter
Is there some reason not to use a microcontroller ( like ie an Arduino ) to drive with PWM a Mosfet and use an analog input to provide voltage feedback and regulate the output, and maybe another ...
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Is it useful to think of SMPS input capacitance as part of an LC filter?
I'm at the stage of learning about switched-mode power supplies that I'm focused on understanding the role of input capacitance. Just for background, I'm working with a buck topology for this ...
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Buck converter problem
I have this buck converter - BD9G201EFJ-M
Buck converter specifications:
Input voltage - 18V to 32V
Switching frequency - 300kHz
Output voltage 9V
Load current - 0mA to 200mA maximum.
I am ...
user220456
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switching noise from ltc3780
I have currently built a buck-boost converter using LTC3780 on a breadboard following this deisgn.
The circuit is calculated and designed to accommodate the input voltage given in the schematic. I ...
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How to calculate bootstrap Resistor in MC34163 Buck configuration
I am designing a DC-DC buck converter with MC34163DWG. I try to understand what value of resistor RB must I use at the buck/step down configuration and I also have questions about the CB capacitor. ...
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CC/CV Buck controller
in this model can anyone explain me how is it going to work in CV mode and where is the potential divider and all, like where is the Vfb
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DC-DC buck regulator MP2359 sometimes damaged when input voltage is high
I use MP2359 (datasheet pdf) to convert high voltage into 3.3V. The input range of voltage is from 4.5V to 24V.
At low input voltages, things seem to be OK. However when I input a voltage of 21V (...
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Capacitor voltage in buck converter and how it steps down voltage
I am having an issue understanding how the a buck converter circuit actually steps down the input voltage. Specifically, my issue is regarding the capacitor charging and discharging. Let's consider ...
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How Does a Buck Converter Maintain a Constant Voltage?
I don't quite understand how a buck converter works in terms of maintaining a constant voltage.
Let's say you have a 5V, 3A buck converter, but you hook it up to a 1K resistor (load) in series to give ...
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What capacitor value should I use for 3.3v from a buck converter IC?
I am relatively new to electronics and trying to design a buck converter circuit using the XL1509-ADJE1. The datasheet specifies that for the adjustable versions (which this is) you should use ...
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Help refining a current control loop circuit
As a follow up to this question. (Sorry if this linking other posts is wrong. I'm new to forums)
Will this design for an XHP70.2 LED Driver with arduino control work to the params specified?
TL;DR: ...
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Redundant DC-DC converter (parallel)
I am building a flight computer for a sounding rocket. I want to include redundant power supplies - in other words: parallel DC-DC converters. What do I need to consider in order to do this? (is my ...
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using buck converter
I have a 6V 3AMP power supply and I wanted to reduce the voltage output to 5V 3AMP.
I saw buck converted on ebay of the following spec. Can i use it to step down 6V to 5V without losing Ampere? or ...
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Calculating inductor value for my buck converter [duplicate]
I'm trying to understand the SMPS operation.
The goal is to select inductor (L1) & capacitor (C1) values that satisfy the working condition below:
V1: 22-26 V range.
Power supply required: 1 A.
...
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LED bulb redesign
As a follow up to this question I decided that it is time to see how should I utilize failed LED bulbs. There're 5 of them now, however in different condition - one does not start at all, some start ...
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