Questions tagged [buck]

A non-isolated DC-DC converter topology which outputs voltage less than or equal to the input voltage

Filter by
Sorted by
Tagged with
0
votes
1answer
27 views

Buck converter in pspice output value changes depending on the resistance. How do I correct this?

I am trying to design a buck converter and simulate in pspice, however I am running into trouble. The voltage on the load (R1), varies significantly when the load value changes. How do I correct this ...
0
votes
1answer
188 views

Why does my comparator not compare?

I have designed a buck converter and I am baffled with its comparator's functionality. The op-amp comparator does not give a PWM, instead it gives an amplified ramp. What am I doing wrong?
0
votes
1answer
46 views

Common mode inductor and diode circuit (EMC filter?)

I found this Buck converter circuit online, but not so sure what's the purpose of the circuit marked in red box and how it works. Please come in and discuss if anyone has an idea of it. Thank you
0
votes
0answers
41 views

Synchronised Buck converter - Soft-Switching

I have a question regarding the synchronised buck converter. This topology is using two transistors instead of a transistor and a rectifier diode. The bottom switch is used to reduce conduction losses ...
0
votes
0answers
58 views

How do I step down my voltage and up my current for a tethered drone

I'm fairly new to this platform but would like your advice on one of the projects that I'm working on. I am currently working on adding a tethering system to the DJI S1000+ spreading wings octocopter ...
0
votes
3answers
93 views

Role of the output capacitor in buck converter in terms of frequency

I am using this DC-DC buck converter - buck converter. Schematics : Buck Converter Specifications : Input Voltage - 18V to 32V Switching Frequency - 300kHz Output Voltage 9V Load Current - 0mA to ...
0
votes
2answers
63 views

DC-DC buck converter low input voltage behavior

I am using this DC-DC buck converter. Schematics : Buck Converter Specifications : Input Voltage - 18V to 32V Switching Frequency - 300kHz Output Voltage 9V Load Current - 0mA to 200mA Maximum. I ...
0
votes
0answers
43 views

Buck converter with current and voltage regulators

I need to find scheme for Buck converter with adjustable output voltage from 0 up to 12V. Also it may have an adjustable current limit. Max current output is 10A or at least 5A. Actually I will need ...
1
vote
1answer
3k views

PT4115 LED driver

Excuse me if my question is too specific. I'm trying to get an LED driver using PT4115 work. I've spent hours but no success. I've created exactly the circuit depicted in the datasheet. I have used 0....
0
votes
1answer
31 views

Control Circuitry in the Buck Converter Design

In this question, the last line of the accepted answer states that - That's why the text suggests using 1/5 or 1/10 of the switching frequency as an upper limit in terms of how fast you should design ...
0
votes
0answers
56 views

Converter stability - bode plot

I referred this YouTube video for buck converter loop stability. In the image we can see that the gain of the control loop we are talking about is Vout / Vin. Vout and Vin are both measured across ...
1
vote
0answers
48 views

Capacitor voltage of Buck converter with LC input filter

What will be the voltages across capacitor C1 and inductor L1 in terms of Vg,D,R? From the amp charge balance equation, i1=-io *D because i2=io.From my observation, Vc1= Vg for 0<T<DTs and Vc1= ...
1
vote
4answers
251 views

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 ...
0
votes
1answer
100 views

Buck converter using LC input filter

Can somebody explain me about the working and waveforms of Buck converter with LC input filter? I can't figure out the output voltage expression using Vg, R and D(duty cycle) and the dc voltage and ...
1
vote
1answer
83 views

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]
0
votes
1answer
70 views

Will 14.4 volts from my solar charge controller damage my 12v equipment?

My charge controller is set to recharge my battery bank and begin a float charge at 14.4 volts. If I use some of my 12 volt components during the day while the batteries are charging, will this high ...
0
votes
1answer
52 views

Buck Converter Feedback Loop - Stability Criteria

Question 1 : I am having some trouble understanding the Stability criteria of the Buck Converter Loop Stability which says, "The cross over frequency should be less than 1/8th or 1/10th of the ...
0
votes
1answer
303 views

Does mobile charger and buck converter have any basic difference?

I have a 2 cell(4.2V)/12Ah deep cycle flooded lead acid battery that i usually charge by 5V/2A smartphone charger. By using this charger it takes 200mA current for charging. Today i got my CC/CV buck ...
1
vote
0answers
52 views

Buck Converter Supplying Boost Converter - Potential Problems?

This post asked a similar question to mine, but the problems that I have noticed are distinctly different. I have a PCB that uses a buck converter to supply 12V from a 24V source, and I am boosting ...
0
votes
1answer
69 views

Buck converter input voltage lower than the designed output voltage

I have this buck converter which is designed to produce an output voltage of 9V for an input range of 18V-36V. The datasheet of the buck converter mentions that the minimum required input voltage is 4....
1
vote
1answer
70 views

input capacitor for buck converter

To calculate the input capacitor for buck converter, I follow TI Application Report SLTA055–FEBRUARY 2006 "Input and Output Capacitor Selection". It says to determine the input capacitor &...
0
votes
1answer
50 views

Multiple transformer windings vs a single winding with a buck converter for dual output power supply?

I have to create a power supply that has both a 5V output at 1A and a 3.3V output at 0.4A. I was wondering if I should add another winding to my transformer or just make a 5V 1.5A power supply, and ...
0
votes
0answers
33 views

Buck converter input/ output capacitance

For a typical Buck (Step down), synchronous converter please consider the given image: I have added numbers there representing the following: Input voltage Input capacitance Output Inductance Output ...
4
votes
2answers
185 views

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://...
1
vote
0answers
49 views

Does adding a line impedance stabilisation network reduce the output of buck converter in simulation in LTSPICE?

I have modelled a 48v to 12v buck converter in Ltspice.When I added a LISN the output reduced from 11v to 6.3v but EMI remains the same.Is it okay if output voltage is reduced?
2
votes
2answers
64 views

Advantages of consequent buck converters

Lets assume we have a 12V source (i.e. an external PSU). We need to go down to 1V8 to supply some load. Leaving the costs behind and using only synchronous buck converters, what are the advantages and ...
0
votes
1answer
61 views

Parallel Usage of Buck Converters | LM2596 Module

For my application, I need three voltages +5V, +15V, -15V Initially, I was using wall socket plugs to connect two 15 volt adaptors, in which I connected the + and - together and considered it as ...
1
vote
1answer
39 views

Synchronous Buck Converter Mathematics

Ive been trying to find a mathematical explanation on how a Synchronous Buck converter maintains continuous operation under ideal steady state conditions. I understand the underlying concept but i ...
0
votes
0answers
24 views

Is it possible (feasible) to use a synchronous buck regulator for balancing batteries?

I need to build for a hobby project, a active balancing circuit for large number of LiIon series cells (90 cells). So it needs to be cheap but efficient :) (ie. not resistive dup). After lot of ...
4
votes
1answer
151 views

DC/DC Switching Converters: Is it possible to run a current-mode converter in voltage-mode only?

DC/DC Switching Converters: Is it possible to run a current-mode converter in voltage-mode only? If so, is there an example using a buck converter? In particular, I'd like to use UC3843 (LT1243) in ...
2
votes
0answers
50 views

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 ...
0
votes
1answer
47 views

Buck converter suggetion [closed]

I want to design buck converter Vin 12V V out 9V I out 400mA. any suitable part / switching frequency I want to use very low like 65KHz
1
vote
2answers
107 views

Inconsistent voltage on buck converter (TPS54240)

I'm currently facing a weird issue. For one of my project I had to design a buck converter circuit in order to step down the voltage of three LiIon batteries to 3.3V so I can power a microcontroller. ...
1
vote
2answers
242 views

MPPT Voltage compensation in current?

Suppose I have a 75w solar panel. At full sun shine it is giving 17 volts 4.41 Amperes 17 × 4.41 = 75 watt. My MPPT controller converts it to 12 volts and 6.25 Amperes 12 × 6.25 = 75 watt. ...
0
votes
1answer
32 views

Wide Range Input DC DC Buck Convetrer Design

Im having trouble understanding how i can achieve a constant output voltage with a varied input voltage. I know how to design a buck converter with a constant output when the input voltage is fixed ...
1
vote
1answer
48 views

Synchronous Buck Converter - Current sourced by the NCH mosfet

I am trying to understand the basic operation of a synchronous switching-mode buck converter. I a continuous-mode operation the inductor current is always positive, hence from the mosfets to the load. ...
2
votes
0answers
59 views

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 ...
0
votes
1answer
84 views

Building a buck converter using CMOS 555 with mosfet driver

Can I use ICM7555 IC to generate 300 KHz PWM signal and feed that PWM to IRL2104 mosfet driver to build a non-isolated DC to DC buck converter? I'm asking this question because I couldn't find any ...
0
votes
2answers
36 views

Two MP1584 voltage converters in parallel

I have a circuit that will need to power different loads at different voltage levels (because they are LEDs of different colors). Can I use several cheap MP1584 modules in parallel (as in: same input, ...
2
votes
1answer
33 views

How does the buck regulator soft start condition reduce the unwanted voltage drops from high impedance power sources?

I have been studying the functionality of the soft start function. I understood how it will help to reduce the overshoot of the output voltage as well. Here, my intention is to understand the meaning ...
6
votes
3answers
3k views

Schematic for common buck/boost converter designs

Does anybody know the schematics of these common LM2596 buck converter with current adjustment and buck-boost converters from ebay? I know I can easily buy it cheap but I like making my own modules ...
1
vote
1answer
53 views

How to make a constant current-pulse current charger for lithium ion?

I've been doing some research about battery charging system with the CC-PC-CV (constant current-pulse current-constant voltage) method. However I have some questions and need some guidelines for ...
2
votes
2answers
103 views

Is this voltage division equation correct?

I am trying to study the significance of resister divider feedback circuit in buck regulator. This is the TI document I am referring to. As per TI doc, voltage at the feedback pin is as follows, When ...
1
vote
1answer
116 views

Why is my buck regulator based on LM22679 limiting current way under the set limit?

I have a LM22679-ADJ based buck converter. The output voltage is set to 24V. The input voltage may vary from 28-40V DC. The current limit is set to above 5A according to the graph given in the ...
0
votes
0answers
280 views

Buck Converter Load Regulation

I have attached a schematic of a buck converter circuit I have designed. It's designed using a LMR16030 IC. Input voltage: 12-14V Output voltage: 5V Switching frequency: 1MHz Output Current: 2A I'm ...
1
vote
3answers
92 views

LDO Efficiency calculation parameter

LDO efficiency calculation output current do we need to consider load current value or LDO maximum current rating? Ex: I have selected TI# LP38841-ADJ Input voltage: 0.95V LDO maximum output current: ...
0
votes
1answer
36 views

Is there an error in the datasheet for the AOZ1284?

I am working with AOZ1284A a buck converter. Datasheet:http://aosmd.com/res/data_sheets/AOZ1284PI.pdf According to the datasheet: I think they mistaken 5000 for 55000. But this works only with the 2 ...
1
vote
3answers
174 views

Output capacitor in buck converter

I am working with the buck converter AOZ1284 Datasheet I want to get 5V with 12V in input so I chose R1=52.3k and R2=10k (Vout = 0.8 x (1+R1/R2) =0.8x(1+52,3k/10k)=4.984V). Also I fixed L=4.7uH. How ...
1
vote
0answers
48 views

Powering ESP32 LDO or Buck converter

im designing an ESP32 system with three haptic drivers. Description of the system: 3 Drivers: 3.3 V 15 mA ESP32-pico-D4: 3.3V Sleep mode: 50 mA Active mode: 150-300 mA Antenna: Compact Reach XtendTM ...
3
votes
3answers
180 views

Is my schematic of the TPS54240 buck converter correct?

I am currently working on a small project, where I have to reduce the voltage from 3 LiIon batteries that are chained together in series to ~3.3V in order to power a microcontroller. At first I was ...

1 2
3
4 5
22