Questions tagged [buck]
A non-isolated DC-DC converter topology which outputs voltage less than or equal to the input voltage
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Inductor in buck converter
I have a couple of questions regarding the switching inductor in a buck converter.
Is it normal for the switching inductor in a buck converter to heat up?
In my circuit, it reaches around 65 Celsius. ...
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How to set current on a cvcc?
I got a cheapo cvcc off ebay.
Setting volts is pretty easy. I just hook my multimeter leads to the output and twist.
But, how do I set amps? I need something to dump the current in. What should I dump ...
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Fully Differential OTA
Based on the figure below, could you explain how a differential ota works ? how can I get the transfert function if I want to set a pole or a zero at the output with a differential resistor and a ...
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MPQ4470-AEC1 Layout guideline clarification
I am using MPQ4470-AEC1 in my design. In the datasheet page no 18 contains the layout guidelines.
I have some questions about guideline no:2 and no:3 .Those guidelines are given below.
Place input ...
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What are the consequences of small bootstrap resistor (in DC-DC buck/step down specifically)?
If I understand it correctly, a bootstrap capacitor (CB) is used to store energy to turn on the high-side MOSFET (P-channel MOSFET). In DC-DC buck converters (which I use now) this happens several ...
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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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Buck converter: PWM modulator input waveform
I have a question about the pwm modulator in a classical buck converter in voltage mode control (VMC). For the circuit in question, I copied over the picture provided in the answer of another SE ...
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Voltage not varying with duty cycle
I want to make a circuit that changes voltages with the duty cycle as well as doubles that for me. I therefore made a voltage doubler circuit along with alternating PWM wave. But as I changed the duty ...
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What technical progress enabled high-efficiency charge pumps?
I found a lot of information on the internet, most of which told me that charge pumps are only suitable for low-power scenarios and they are not very efficient.
Charging ICs based on the charge pump ...
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Power dissipation formula
Is the below formula, present on page 26 of this buck converter correct to use?
Or should I use the formula mentioned in the 3 paragraph of this accepted answer?
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Non-synchronous buck ASIC's diode selection makes sense?
While selecting buck converter ASIC for a design I came across various synchronous and non-synchronous buck converter from different manufacturers. Synchronous buck are OK - no problem with SW node ...
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Buck converter inductor ripple current percentage
I am designing a buck converter using LMR36015 (Texas Instrument). The specifications are:
Input voltage: 24V (+/-10%) = 21.6-26.4V
Output voltage: 3.3V
Output current: 0.4A
Fsw = 1MHz
This leads to ...
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Safety circuit for N-channel MOSFET failure (internal short) of buck converter
Consider the following simple low-side N-channel MOSFET based buck converter:
One of the dangerous situations for the load connected to this kind of buck converter (especially if the load is a ...
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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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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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Custom PCB based on LM2596SX-3.3 shorting out
I designed a custom pcb based on this https://github.com/azrael783/esphome_garagedoor_opener and this https://github.com/jampez77/garage_door_sensor for esphome/homeassistant
I nailed the esp part but ...
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Unable to start and run 12 V DC pump, only jolts
I have a 12V 19 watt DC water pump (800LPH), A 12 V DC step down converter, and two Dewalt batteries.
One at 18 V 5 Ah, other 18-54 V 9 Ah.
I've connected pump to step down to battery correctly, but ...
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Will a buck converter clean the power output from an automotive?
I want to permanently attach an ESP32 module and an LTE modem/hotspot to my car. I want to power these two devices using the car's cigarette lighter socket. The socket gives 12 VDC so I will be using ...
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Buck Converter Output Voltage Swing problem
I am designing a voltage mode control buck converter and I have an issue with my output voltage swing. I made calculations for type 2 compansator. I can't figure the cause of problem is stability of ...
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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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DC/DC split rail converter like TI's Fly-Buck™ coupled inductor topology but with a non-inverting buck converter
Introduction
First of all, I hope you can read this through. It's rather long!
I was trying to design a DC/DC converter for a Class-D amplifier that requires a 48V input and also an auxiliary 12V ...
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Thermal analysis of a step down regulator
LTM8053 datasheet
I tried to plot the thermal graphic (watt-celcius) for this buck converter in MATLAB. The main goal is to find losses which turn into heat. Reasons for heat most of time switching ...
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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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What is the standard form for writing the second order transfer function for Input impedance?
When writing the transfer function for a system, the Characteristic equation in the denominator which carries information about the poles of the system is equated with the standard second order ...
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How to model PCB parasitics
I am working on a buck converter on a PCB. I would like to run some LTSpice simulations to see the impact of the parasitic inductances and resistances of the traces and coupling capacitances.
Is there ...
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Lithium Ion Battery : Cell Array Configuration (V.batt when converting to ≤ 4[V] )
Question
I am seeking to array 6x 21700 lithium ion battery cells, leaving the option for:
1S • 6P (@ V.batt.nom = 03.7 [V], range: 02.7—04.2 [V])
2S • 3P (@ V.batt.nom = 07.4 [V], range: 05.4—08.4 [...
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Problem with the current in a multiphase buck converter
I am a student of electrical and computer engineering and am currently working on a project that involves the study of a multiphase buck converter or synchronous buck converter (2 phases, in my case).
...
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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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High Current Step-Down Conversion 12V-5V/100A
I inherited two 12 V, 1200 W server power supplies a while back and I'd like to press them into service as electrolysis cell power supplies for making (per)chlorates. I need to drop the output to ~5 ...
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Buck and boost converter inductor confusion
I have seen that a boost converter uses the spikes of an inductor to step up the capacitor voltage as this spike is stored on the capacitor.
Why don't we get a similar effect in the buck converter? A ...
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LM2576 TI Simulation not working
I have used the PSPICE model of LM2576 IC from the Texas instruments but the simulation is giving me false results. I have used the exact same diagram from the datasheet but the IC is not working. I ...
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Difference OTA and op-amp
I have a question about OTA (operational transconductance amplifier). Why can an OTA can be used without negative feedback but would still be able to keep its inputs (V+, V-) close each other? I have ...
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Compensating for lack of via-in-pad for buck converter thermal design
I am designing a buck converter, based on a TI chip. Both the datasheet and an excellent document "Five steps to a great PCB layout for a step-down converter" show vias in the exposed pad, ...
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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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Modulator Small Signal Transfer Function
How is the transfer function derived from that figure?
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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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LC filter out of the loop if crossover frequency is below resonant frequency?
Referring to slides 78-84 of http://powersimtof.com/Downloads/PPTs/Chris%20Basso%20APEC%20seminar%202009.pdf, the RLC network rings alone and the oscillations are not due to the loop.
It is my ...
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How much current should a switching regulator consume on its own?
With your help on stack exchange, I finally finished assembling my first LM5143QRHARQ1-based buck converter! And it works! It does output 7V (well 7.03V) The only problem is that it consumes around 0....
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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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Buck converter - what to do with the rest of the duty cycle
I am looking into making a MPPT charge controller for some solar panels - I understand that it works on the basis of using buck converters to get the most efficient voltage to current ratio for the ...
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DC-DC variable resistor's side
I plan make DC-DC mini-PCB PCB like it. In my schematic I want regulate output voltage. Because of it I made R1 as variable resistor. In my schematic I am afraid that middle pin of variable resistor ...
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Why is there an output ripple on my LM2576? [duplicate]
I built a buck converter using the LM2576HVT-15/NOPB. I built it exactly like the recommended schematic:
The diode I am using is a 1N5822 and the inductor is a 470uH inductor with a 100uF ...
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Can a buck converter functioning in CCM have non-linear behaviour at light load currents?
I've been designing a Simulink/Simscape model of a TI buck converter launchpad (https://www.ti.com/tool/BOOSTXL-BUCKCONV) and I'm trying to have my model fit the behavior of the device.
The board can ...
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PFC Boost Converter
I have two questions regarding PFC boost Converter.
Why boost converter is preferred over buck for PFC?
What is the difference between PFC boost converter and a traditional Boost converter?
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Reverse recovery diode power loss in switching MOSFET
For designing a low side non-sync buck regulator I am looking for MOSFET(s) that can provide low overall power loss. Conditions would be 60V to 48V, 10A, 600 kHz (worst case), 1 Ohm source and 0.35 ...
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How to calculate bootstrap Resistor in MC33163 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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Choosing capacitors for Buck Converter – How many Electrolytic, How many Ceramic?
I am working on a high-power buck converter. This converter will be powering a purely resistive load (it’s a literal resistor – a heating element).
However, I am having some issues deciding how many ...
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Is the PCB routing for this LM5143A-Q1-based buck converter right?
Thanks to your advice on StackExchange, I'm in the final stage of developing my first LM5143A-Q1-based (link to datasheet) buck converter! It may be a bit rushed as I need to prepare this for a high ...
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How to convert a {200 VDC, 3A} power supply into a {12 VDC, 50A} source?
As title states, want to convert a high-voltage, low-current DC bus to a low-voltage, high-current DC bus that's more compatible with electronics circuits. This seems to be a pretty large input for a ...
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Final design considerations for LM5143A-Q1 buck converter. Are these features needed?
After a few days of learning how to make a buck converter using the LM5143A-Q1 TI IC, it's finally becoming a reality! This is the final design, highly inspired from page 30 in the datasheet, some ...
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