All Questions
Tagged with buck power-electronics
129
questions
0
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Buck Average Modelling
I completed average modelling with Voreperian PWM switch model as described in Christophe Basso's book "Transfer Function of Switching Converters" and I compared the average model with ...
- 119
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1
answer
101
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Buck Converter Peak Current Mode Control Average Model
I am trying to understand average model of Buck Converter for Peak Current Mode Control Topology.
Below snapshot taken from Christophe Basso Webpage(https://powersimtof.com/Spice.htm) from file "...
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2
votes
1
answer
81
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Peak current mode control loop compensation calculations
I recently came across a rather nice straight-to-the-point application note by RickTek (AN028) on how to calculate approximately the compensation network of a PCM buck regulator.
Link : https://www....
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3
votes
6
answers
1k
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What is an intuitive explanation on how a buck and boost converter transfer energy?
I can understand how a buck converter can step down the voltage but only with the formulas. I am struggling to understand intuitively how the inductor stores energy and releases it in a way so that ...
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1
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3
answers
78
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For a high powered LED loads, is a buck or boost converter more efficient / simpler?
I have a 3 high powered LEDs hooked up into a strip to for the load. For simplicity, I am going with a constant voltage driver. The load can be hooked up in 2 configurations:
Config 1:
3 Green LEDs (3....
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7
votes
2
answers
747
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How do buck regulator modules with integrated inductors manage to be so small?
This 20 A buck regulator module from TI is 6.5x7.5x4 mm and has an internal 330 nH inductor.
This 6.5x6.5x3.1 mm 330 nH inductor from Coilcraft has an RMS current rating of 18.8 A and is the smallest ...
- 95
1
vote
3
answers
206
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MCU Controlled Buck Converter IC
I am designing for an application where I need a buck converter that takes the voltage from a 2S Li-ion battery (6-8.4 V) and the load I need to drive is 0-6 V and will take 1.2 A max. I need to ...
- 113
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1
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48
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Identifying MOSFET (P9DVA) and diode (AD6) Markings
I need help identifying a MOSFET and a diode in a circuit, specifically on the Pololu board D24V25F5.
While researching, I came across information about a diode (NSVR0340) with the AD4 marking. ...
- 903
2
votes
1
answer
56
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Buck converter inductor waveform having high ripple and slow charging and fast discharging [closed]
The following shows the voltage (green) and current waveform (yellow) across an inductor in a buck converter designed to step down 30 V to 15 V with 0.2 A output current.
The inductor values according ...
0
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1
answer
69
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Schematic review MAX20029ATIAV
I am using a MAX20029ATIAV in my design for powering a Quad Tunneling GMSL2/1 to CSI-2 Deserializer.
MAX20029ATIAV is Quad Low-Voltage Step-Down DC-DC Converters.
My schematic is given below. May I ...
- 2,593
3
votes
3
answers
788
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Input impedance of a buck converter
Is there an approximate formula for calculating the minimum value of the input resistance (or impedance) of a switching regulator? I found several formulas but can't figure out which one to choose. I ...
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0
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94
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Buck converter with some big ripples
I am simulating a buck converter (schematic at the end) (datasheet) and I observe bigger spikes in addition to the normal ripple. In the screenshot below, Vout is in green and the buck converters SW ...
- 288
-1
votes
1
answer
93
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Problems with buck converter
I designed a PCB with two LM61495 buck converters. They should produce a 3V3 and 5V output. However, for both circuits, the output is 12V. The picture below shows the output of one of the channels ...
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2
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1
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322
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Identification of IC used in Pololu 5V, 5A Buck Converter (my2101 330)
I have identified the chip on the Pololu 5V, 5A buck converter as my2101 330, but I am having difficulty finding information about this chip on any platform. I've checked the Pololu resources page (...
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1
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3
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341
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Buck Converter Step Response Analysis
I am new to power electronics and control, so I am confused with the following. I have a simulation of a Buck converter, and PID controller in Simulink. I did some trial and error tuning, and I have ...
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1
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117
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AP63203 Buck not working
Recently I have been experimenting with the AP63203, and I just have not been able to get it to output 3.3V successfully. Currently, the way I have been testing it is using an SMT to TH adapter, which ...
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0
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1
answer
131
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DC-DC buck converter's MOSFET or IGBT?
Motor Specifications:
Rated power: 50 kW
Rated voltage: 200V DC
Rated current: 250A
Battery Specifications:
Nominal voltage: 400V DC
Capacity: 50 kWh
Design Requirements of the DC-DC Converter
...
2
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0
answers
120
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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 ...
- 163
0
votes
2
answers
153
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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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1
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1
answer
114
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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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1
answer
75
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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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0
votes
1
answer
109
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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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0
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45
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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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1
answer
357
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Modelling the PID controller for a Buck Converter from a given schematic
I followed a document to implement a PID controller for a Si MOSFET based buck converter as the traditional multistep analog PID converter was not giving any good results for some reason. The document ...
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1
answer
79
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Efficiency curve of synchronous DC-DC controller with external MOSFETs
I'm designing a 48V to 12V, 300W buck converter. I am considering using the LM5148 controller and NTMFSC004N08MC switches. I'm confused about how synchronous DC-DC controllers can list efficiency ...
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0
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1
answer
50
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Variable Vout of Buck Converter [duplicate]
I have been trying to understand the working of buck converter (without the use of a dedicated IC). So, I used LTspice to test a circuit on the parameters:
Vin: 100 V
Vout: 50 V
Freq.: 10 kHz
I: 5 A
...
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1
vote
1
answer
191
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Buck converter simulation(Psim) always return the half value of the output voltage
I try to design a buck-converter in PSIM simulation program. Let me write the circuit's requirements:
Frequency = 80kHz
Ripple < 0.5%
\$V_{input}\$ = 30V
\$V_{out}\$ = 12V
\$R_{load}\$ = 10 \$\...
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2
votes
1
answer
280
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Issues with voltage spikes on buck converter design
I am building a buck converter that I eventually plan on using in an MPPT charger.
I have not taken any power electronics courses.
Below is the spice model I’ve been using.
The issue is that point A ...
0
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1
answer
446
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Buck Converter Gain Margin and Phase Margin Review
I am using this IC (MPQ4470) for designing a buck converter (12 to 5 V - 3 A). Below is my circuit.
I am checking the stability of this circuit. My phase gain plot is given below.
My PM is 92 degree ...
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0
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35
views
Power dissipation of synchrononous buck converter cannot be reduced with gate drivers?
For this project, I had to want to reduce the power dissipation (< 2 mW) when the Rload is 54 Ω. These are the two circuits that I have employed.
When I sweep the pwm frequency vs Pdiss (power ...
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1
answer
319
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What role does the inductor and output capacitor play in a buck converter? [closed]
What role do inductors and capacitors play in buck converters?
I know it acts as an LC low-pass filter.
What other role does it have? When the switch opens, does the capacitor discharge in the load? ...
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1
answer
85
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Buck Converter Output Is Coming To More Than The Designed Value After 3 Or 4 Months In Some Boards
I have a buck converter which converters 12V to 5V,3A. The output of this buck converter is going to a load switch and from the load switch it is going to a connector.
What we observed is that after 3 ...
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1
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72
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MPQ4470 12V to 5V, 3A output is not simulating as expected in SIMPLIS
I am new to SIMPLIS, simulating this IC for converting 12 V to 5 V.
My first SIMPLIS circuit diagram is given below. My input is 12 V and the required output is 5 V. The load will take a maximum ...
- 2,593
1
vote
2
answers
1k
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Minimum Inductance for Buck converter to maintain CCM
In a buck converter, consider all components to be ideal; the
output voltage is kept constant at 5 V by controlling the duty
cycle. The input voltage varies between 10 V to 40 V, the
output power is ...
0
votes
1
answer
128
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Wider width or more fingers for CMOS transistor to reduce conduction loss in syncrhonous buck converter?
For a project, I am trying to optimize my buck converter to obtain a power efficiency of 87 %. The non-optimized buck converter gives a power efficiency of 86 %.
I try to size my PMOS 'power' ...
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0
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78
views
Can the MP9488 circuit be operated at 333mA output current?
I am looking to use the MP9488 as a buck Switching Regulator with a voltage output of 12V and output current of 333mA. In the application note it has an output current of 300mA.
As far as I understand ...
2
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2
answers
2k
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How do switches work in ltspice?
I Have set up my switch according to the rules specified, using the dot command to determine the behavior of the switch but I still get the error.
"Can't find definition of model 'S1'"
I ...
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4
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2
answers
3k
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LTspice Frequency Response Analyzer (FRA)
This post is a continuation of this question.
LTspice recently introduced a new feature called frequency response analyzer, see the image below.
The green box shows the symbol for FRA. If you click ...
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0
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114
views
Buck converter inductor selection: maximum switch current limit vs output current
I need to select an inductor for this buck converter. Its output current is 3 A and maximum switch current limit is 6 A. As far as I know, I need to select an inductor whose current ratings (both DC ...
- 2,593
6
votes
2
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967
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How to measure the stability of a buck converter using LTspice
Below is my buck converter circuit. How can I check its stability using LTspice?
I need to measure GM and PM.
Is this true that a 30–60 degrees phase margin and a gain margin of 2–10 dB are desirable ...
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0
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332
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Ferrite bead in series with buck inductor
Background
When filtering DM noise from SMPS, I have often used LC filters in the past. One thing that happens with regular inductors though, is that very high frequency (>100 MHz) switch noise ...
- 22.5k
1
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1
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114
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PFC (Power Factor Correction) harmonics
I recently succeeded in creating a powerful buck PFC with a value almost equal to 1 (0.999)
As you know there are always problems when dealing with real life circuits. I mean, the PFC value is real, ...
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0
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1
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113
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Buck converter confusing output voltage waveform
I've constructed a simple DC-DC buck converter circuit in Simulink with ideal components.
I'm getting a weird output voltage waveform. Although the average output voltage matches my calculations, the ...
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3
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0
answers
96
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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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1
answer
374
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In MOSFET switching loss calculation, where does the 0.5 factor come from?
I am going through this material for calculating the switching loss of the mosfet.(https://www.monolithicpower.com/frequency-selection-in-switching-power-supply-designs-part-i)
The switching loss ...
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2
votes
1
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127
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AC input buck converter output ground oscillating
Attached the buck converter complete circuit. It is working fine and the output voltage is staying constant.
But, just before the mosfet is turned on, the out_gnd ...
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0
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63
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Would a square waveform (or trapezoidal waveform) have frequency content lower than its fundamental frequency?
I was trying to understand the LC circuit response for the circuit given below.
(Note: fsw indicates the frequency of input square wave as in a buck converter)
As far as I know, for a linear circuit, ...
- 3,032
2
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1
answer
581
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Buck-Boost Converter Inductor Value
I am designing a typical buck-boost converter using the LTC3530EMS#PBF IC from Analog Devices.
My design specs are as follows:
Vin: 3.0V - 4.2V
Vout: 3.3V
Iout(max): 300mA
Fsw: 1MHz
In the datasheet, ...
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1
vote
1
answer
57
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Power supply connected to multiple buck converters, input current requirements
I have a 24V/40A power supply with a foldback current limiter. And I need to connect 76 buck converters of 5V and 2A each to it. Since the current of the power supply is limited and considering that ...
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1
vote
1
answer
89
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Charging a power bank with a solar panel
Is there either a simple circuit that I could build, or a good circuit/pre-made board that will charge up a 6700mAh/5V/2A power bank with a small solar panel that is attached to the cover of an ...
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