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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Startup transient on LMR14030-Q1 buck converter
So I'm trying to build my first buck converter for an audio project using a TI LMR14030-Q1. My first design had some acoustic noise so I changed the switching frequency, inductor, and output ...
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LM4510 Switching Converter not working
I am using a TI LM4510 converter (datasheet) to step up from 5V to 12V (adjustable). I have good input power, enabled chip, and followed datasheet, but the output voltage is actually lower than the ...
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Output voltage not stable - What is compensation with respect to DC-DC (buck converter)?
EDITS:
Input voltage range: 24V to 48V.
Changing the load current from 0.38A to 1.018A increases the mean output voltage from 12.779V to 13.26V. The supply should be producing 12.5V.
I'm using this ...
user220456
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Need help to identify this IC
I am struggling for about three days now to find the part number for U118. Tried every online database, but I still cannot figure it out. Marking is 14YN/H 891 A981.
Any ideas about which manufacturer ...
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LM3150 Webench not matching with LTSpice?
I'm trying to implement this design from Webench (5V @ 10A):
I'm using LTspice to simulate this design, but my results are bizarre, as shown here:
I have looked into this thread: TI Webench and ...
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Half-bridge circuit not working, high side running hot
As I'm a noob in this field I’m experimenting with a half bridge circuit to run a buck converter to learn about it. First I tested my circuit by putting everything together on a breadboard and it ...
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Inrush Current problem?
I have a 360W 36V Switch Mode PSU which I am using in a garden lighting system I have designed. I'm in the UK so it's running off 240V therefore can supply about 10A.
Each section of the ...
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Phase shift at half the switching frequency of a dc-dc converter
I would like to know if, regardless of the control loop used (Voltage mode control, average current mode control, peak/valley current mode control), there is always a 90-degree phase drop at FSW/2 due ...
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Power circuitry not coming up
I've created a PCB that has two buck/boost converters, the second one being connected to the output of first one. The enable pin of the second buck converter is connected to the PG pin of the first ...
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Double frequency buck converter - minimum values of smaller and larger inductances
Consider a double frequency buck converter shown below having small and large inductors operating at higher and lower switching frequencies respectively, in order to improve both the transient ...
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Output Capacitor Design for a Multiphase Buck Converter
According to this application note from Texas Instruments, in the design of the output filter for a multiphase buck converter there are basically two ways of choosing the output capacitor. The first ...
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Feasibility of my Buck Converter Design
I aim to design a simple open loop non-synchronous buck converter for a project at my college with the following specifications.
Parameter
Value
Input Voltage
10-30 V
Output Voltage
5-9 V
Output ...
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Device not working after 12V to 5V buck converter
I'm kind of upcycling an old radio with radio, Bluetooth and cast features.
The Bluetooth module and the amplifier for the speakers work with 12V so I chose a 12V power supply. It works well. When I ...
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Checking calculation of phase and gain margin in LtSpice
I am currently studying DCDC stability analysis in LtSpice. Could you please check my phase margin calculation, am I right? And how about the gain margin calculation? Is it equal to infinity in my ...
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Buck converter driver LTC4446 running too hot, too high current
I am trying to design a buck converter, but the driver LTC4446 is getting to hot with this design and the input current is also to high (130 mA), when it should be in the uA orders... Any ideas of why ...
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Is it true that power supply design is difficult when input voltage range is wider?
During power supply (buck converter) testing, I had seen the lowest efficiency values corresponding to highest input voltage. I thought if the design meets this worst case scenario, it should be ok no ...
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EMI Filter For Low Power SMPS
I've designed a 1.25W buck converter which is fed by 220VAC(85-265) and has a 5V output. Now I'm trying to design a EMI input filter for it. I don't have a PE connection so I didn't use a CM filter so ...
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Buck converter with state feedback: does changing the input voltage changes the dynamic of the converter?
Short question: in a buck converter with state feedback, do changes in the input voltage cause changes in the dynamics of the output voltage (and inductor current)?
The problem: let's say we have a ...
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EMC (radiated emission test) issue in buck converter
i am designing CV smps 12V 1A (with EMC design) post that output side i will use dc to dc buck (Vin-12V Vout-9V, 400mA) or Boost convreter (Vin- 12V VOut-36v, 100mA). which configuration will be more ...
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reverse voltage polarity protection
I'm thinking about making a reverse polarity protection for a buck converter AOZ1284, and I've found this article design-guide-pmos-mosfet-for-reverse-voltage-polarity-protection
I didn't find the ...
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Powering buck converter using charged capacitor
Is it possible to design a buck converter using a charged capacitor to get regulated voltage output? When the capacitor voltage falls below some threshold value the inductor should be able to provide ...
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Inconsistent Output Voltage in DC-DC Buck Converter
I'm trying to implement the following tps54302 DC-DC buck converter, for a 5V 3A output:
All resistor values 1% tolerance, capacitors 5% tolerance, inductor 20% tolerance.
I'm testing with a bench ...
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Stability of Buck Converter when output capacitance is variable
I am designing a buck converter for an application that has several different loads. Depending on what devices are connected, the capacitance seen at the output of the buck converter can vary ...
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NCP3420 failing in buck converter
I designed a constant current buck DC-DC super-cap charger with the NCP3420 as a dual MOSFET driver. The current is hysteresis controlled and the disable and PWM lines are pulled low on power-up.
The ...
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Any specific precautions should be taken when using 2x AA LiSOCL2 batteries in parallel?
I am working on the wireless sensor design and one of the sensor is such that it needs to be kept ON through out the operation and it takes supply of 3V and current of about 100uA, which I think is ok ...
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Advanced ATX Power Supply Modifications
I know there are multiple tutorials and questions regarding converting an ATX power supply, new or old, to a benchtop power supply for projects. I'm fully aware of how to make the basic conversion to ...
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very high current buck converter
Need to convert 40 volts to a 24 volt 2000 amp 1 second duration pulse. long duty cycle. Current must be settable from 500 to 2000 amps and time from 0.1 to 1.0 seconds. Ideas please.
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Calculation for the Boot Strap capacitor
For design of a synchronous buck converter (which would be used to charge the battery) which would be driven by Micro-controller's PWM output, i selected the IRLB8748 NMOS Power transistors (for both ...
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Suitable switching/buck regulator - Vin = 24V and Vout = 5V and max current = 0.4A
Due to a sudden change in design requirements with regards my circuit supply voltage I'm looking to change my voltage regulation on my circuit from the classic LM7805 linear voltage regulator to a ...
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Variable switching duty cycle for buck converter even if input voltage and output load is constant
I am testing a BUCK converter and observed that has a variable DC when supplied at input voltages lower than 9.5V (if input voltage is higher than 9.5V the BOOSTER stops and DC is constant). The BUCK ...
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Getting "Too few nodes" error
While I am trying to simulate this LM5164Q buck converter IC exported from TI, I'm getting the too few nodes error. How to rectify it?
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Input capacitance estimation for a buck converter
To estimate minimum input capacitance required for a buck converter to help with power stability & noise suppression, I came across below equation by TI.
https://www.ti.com/lit/an/slyt670/slyt670....
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Running a Motor Controller, Motor, and Raspberry Pi off the Same Power Supply
I have a 24V brushed motor, a Raspberry Pi, and a Teensy 4.1 microcontroller all running off the same power supply (a 24V tool battery). I have a step down regulator that converts 24V to 5V:
https://...
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Input filter for switching regulator
I'm trying to create an input filter for a switching regulator for automotive application.
My aim is to make a supply board, where from 24V come out 12V (from the buck) then 10V and 5V (from two LDOs)....
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Best way to control large buck converter?
I am looking for a faster way to control output voltage for a buck converter.
This buck converter has its own fet driver and I am not willing to change it. I really only need the signal to run the ...
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How do I properly import a .lib description into a LTspice symbol?
I am trying to simulate the TI part TPS62808 in LTspice, Pspice for TI, and Tina TI. I managed to easily run the simulation in the latter two simulators, but the models were specifically made for them,...
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Using a capacitor to handle the inrush surge power of a fridge
I have a household mini fridge connected to my off grid electrical system, and recently I bought a smaller inverter just for the fridge so that I can turn my larger inverter off to reduce power ...
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Unable to find Gvd of a buck converter using LTspice
I'm trying to simulate a closed-loop buck converter in LTspice. I'm using ideal components. I started by finding the Gvd of the buck converter (duty to output transfer function). I used the .ac ...
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Modifying XL4015 CC/CV Buck Converter for Undervoltage Lockout
I am trying to convert a XL4015-based CC/CV buck converter module to CV with undervoltage lockout. At this point I am hoping someone can double check my schematic for glaring errors before I attempt ...
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The best way to step down 12V to 5V with at least 10A current from a PS3 power supply for a WS2812B LED strip
I am new to electronics. I had a PS3 Super Slim power supply lying around, which outputs 12V up to 13 amps. Recently, I bought a 5-meter strip of WS2812B LED strip, which needs 5V, and the recommended ...
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Are the prinicples the same for designing a high side vs low side buck?
I am an analog engineer that is getting into SMPS design.
This is a high side buck:
This is a low side buck:
simulate this circuit – Schematic created using CircuitLab
Assuming that I take ...
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Synchronous buck battery charging circuit using totem pole gate driver
Background - We are trying to develop a very low cost buck (day time)/boost (night time) converter for charging LFP batteries (day time) and powering LED (night time). Due to cost impact we are trying ...
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Noisy signal output from BD2320 MOSFET driver
I need help or technical solutions relating to this issue I encountered with BD2320.
I intend to use two BD2320 drivers for an interleaved buck converter. One of the channels works well, but after ...
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Zero due to ESR in buck converter
How come the equation given leads to one answer for the zero location (marked 1) whereas my intuition leads to another (marked 2)
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How do I use the TPS5403 DC-DC buck to get 3.3V output from a 5-15V input?
I am trying to use the TPS5403 (datasheet) buck converter to power an ESP32 at 3.3V from an input of 5-15V, however, I can't find enough resources online to be sure in my design.
Below, I have ...
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Choosing an appropriate gate driver for IRLZ44N high side for a buck converter
For the TL;DR folks:
Need high side NMOS gate driver IC, similar to Julian Ilett's DCOI driver but cheaper, higher switching speed and less complex;
THT highly preferred, because 1,27mm perfboard is ...
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Switching Voltage Regulator not Outputting Correct Voltage
I am working with a LM2576T-ADJ that is taking as an input voltage a 2 cell Li-Po battery that in my application won't decrease below 8V and should output a voltage of approximately 6V to power a pair ...
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Buck converter programable CC with DAC
I am trying to implement a programable CC (Constant current) functionality into the utilized buck converter (AP64501SP-13). The converter is to be used for series cells charging. I need to be able to ...
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Battery charger circuit confusion - drive and compensation
I'm building something that is going to have Li-Ion batteries so I'm trying to learn how a battery charger actually works. I've been looking over the datasheets for the BQ2000 and the BQ2954. I will ...
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Low-side push-pull transistor of MOSFET gate driver damaged
I have a buck converter as shown in the given figure (48 V output):
At rated loads the buck converter operates correctly as expected. When I test the circuit with the over-current and the short-...
