# 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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### High voltage buck converter, voltage limiting bypass

I am designing a system for a 3.5 kW wind turbine that has a large input voltage range, from 0 up to say 750 VDC. The output voltage should not exceed 600 VDC. I would like to make a voltage limiting ...
45 views

### What is the difference between buck and step-down converter

I always thought "buck" and "step-down" are synonyms. But now I'm looking at two datasheets: CAT4201 CAV4201 They seem very similar, but the first is described as "350 mA ...
37 views

### Buck regulator transient response explanation

I am using TPS5450 buck regulator and trying to measure the transient response but seem to see a weird triangular adjustment before it settles. I can't see anything in the datasheet that would explain ...
454 views

### High-Side NMOS for Buck Converter?

I'm working on designing a buck converter, so I've been using LTSpice to simulate the circuits. However, it seems that I'm misunderstanding something. My understanding is that one should not use an N-...
35 views

### Design of DC-DC Converters

While designing buck converters (or boost converters), why do we usually fix some percentage of the Ripple current (or ripple voltage) and from this percentage, we arrive at the value of inductor and ...
58 views

### How to improve buck converter's efficiency

I am designing a buck converter for 600 - 10V converting (60 times lower than input). My first question - is this even possible? I've seen a 650 - 40V converter on mouser, but that is the best that I ...
34 views

### Using a buck converter with potentiometer for my battery-operated fairylights — Blinking and no read-out on voltmeter

I'm an extreme newbie when it comes to electronics, and decided to just dive right in. I wired up my buck converter exactly like how it's done here: https://www.youtube.com/watch?v=fmdxSRaVPVg Without ...
43 views

### Is there a thumb rule for the input and output capacitor for DC-DC converters?

If we are using a buck converter of say 5V 1A output, we definitely require input and output capacitors. Just without making any calculations, is there a thumb rule on what the values of the input and ...
44 views

### Design a PMOS Buck Converter - some guidance needed

EDIT2: updated schematic and changed pictures. EDIT: Some data: Vin ~24VDC/12VDC Vout ~12VDC with worst case 4A peak current (short) or around 2A continuous. Parts: PMOS Schotky Inductance Board is ...
75 views

### Choosing TVS diode

We have a a project where there a system powered by 13s Li battery - 54.6V max voltage of pack. The buck regulator we're choosing for this has an absolute max of 76V. For this we're considering two ...
65 views

### Buck converter vs LDO

I have a simple STM32 MCU board design that will be sleeping most of the time, waking every 30 minutes to take some measurements (which take about 20 seconds max), and then going back to sleep. It ...
38 views

### Disadvantages of routing inductor in Buck Converter on opposite layer?

I am routing a TPS562202S buck regulator, using a 4.7 uH inductor. Due to space and assembly constraints, I cannot place the inductor on the same layer as the regulator. The regulator will be on the ...
161 views

### Power Supply Interview Questions

I recently attended a Electronics interview. I was asked this question - What should I take care in a buck converter layout? One of my response was like - To place all the associated capacitors, ...
33 views

### How can the output current be programmed in Step-Down Regulators?

I use analog device's LTC3649 regulator as step down regulators. It is said that there is a programmable output current in the datasheet, but I have no idea how to do this. Anyone have an idea or ...
46 views

### How to design a buck converter with feedback?

I design a simple circuit activates fan when processor heats up and then control rotation speed. I got the idea to create a buck-mode step-down voltage converter. However, I would like stabilize ...
54 views

### 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 ...
20 views

### Buck Converter Feedback path

I have this buck converter - TPS54260 I was doing this Control Loop Stability test. For this test, we need to place a small 5-10ohm resistor on the resistor divided feedback path of converter Keysight ...
99 views

### Buck Converter - Output Voltage Ripple

I just would like to ask about the small-ripple approximation and output ripple of buck/boost converters: I understand that in a buck converter, there is an LC filter at the output. If correctly ...
29 views

### Buck converter remote terminal

I'm testing a LED setup, I have a bench PSU going to Traco 5V buck converter that feeds 10 LEDs (SK6812). When I power the bench PSU on, before it hits 12V, the first LED in the strip flashes for a ...
57 views

### How to select external components for a buck converter?

I design a simple circuit activates fan when processor heats up and then control rotation speed. The fan has a brushless motor with an internal motor controller. So I got the idea to create a buck-...
46 views

### Buck converter (TPS54331) oscillating

I have designed and built a buck converter based on the TPS54331 which oscillates at 5.4kHz with an amplitude of 700mV peak-to-peak under a 1A load. I want to remove these oscillations. Here is a ...
621 views

### Why do buck converters end up in steady state?

I'm studying buck converters such as the one in the following simulation: I have learned that for buck converters that are in continuous conduction mode and at steady state, the following equation ...
71 views

### ZVS buck converter

How do I implement the zero current detectors (ZCD) in the buck converter? I want to use it to implement the ZVS buck converter, and I need to detect the zero current, but I have no idea about ZCD. ...
39 views

### Buck / LDO combination

I have a design question. My design has grown in complexity because of new sensors (requires 5v). In the old design a 3v3 output from my buck was sufficient, however now I have to create both a 5v and ...
52 views

### Maximum Voltage at CBOOT resistor and capacitor

I am using this Buck Converter to generate 3.3V output at 0.45A with Switching frequency of 2.1MHz. Input voltage range is 6V - 16V. LM63625 2.5A Part is selected. My questions : Question 1: In the ...
45 views

### Power Converters - Small Ripple Approximation

Hi, I'm having some difficulty understanding what they mean when they said they are able to replace the 'exponential or damped sinusoid waveforms' - what exponential or sinusoid waveforms are they ...
62 views

### Changing the feedback branch in Buck converter

I am trying to implement output voltage remote sensing in Buck converter. I am taking the feedback from the load side. I have made a circuit which can act as a local or remote as per the active ...
348 views

### What component provides the bulk of the current in a buck converter? the capacitor or the inductor?

I’m studying buck converters and I have found contradicting sources claiming either of these statements: The inductor stores and releases the bulk of the current, the capacitor is there just for ...
121 views

### High power buck converter LiFePo4 charger

I’m planning to charge my 48V LifePo4 battery bank of some HV solar panels (Max 140V, MPPT @109V). Since I'm quite interested in the construction of power conversion electronics, I thought I would try ...
83 views

### buck converter in CRM

I would like to simulate the ZVS Synchronous rectification buck converter, I know if I operate in ZVS I need to change the switching frequency of the buck converter. Here are my questions: How to ...
40 views

### Closed loop control ZVS buck converter

I have a buck converter of 400 V input, 200 V output, 300 kHz switching frequency, power output 100 W. I am trying to put it into closed loop voltage mode control. It is working DCM mode. Modelling ...
31 views

### Bulk capacitance equation derivation from appnote

I am looking at SLTA055 by Texas Instruments. It discusses, among other items, how to determine the bulk capacitance required for a buck regulator if a LC filter is used. Since the "L" will ...
70 views

### Buck and boost converter in series

I have a project where I'm looking to power a ESP32 module with 3.3 V and a logic level shifter with 5.1 V. The project will be powered by between 5 and 24 V. So my plan is to have a buck converter ...
36 views

### Understanding Power Good Signal in TPS54719

I'm using TI TPS54719 DC-DC and I'm trying to understand the PWRGD signal functionality. Definition of PWRGD pin in datasheet: An open drain output, asserts low if output voltage is low due to thermal ...
40 views

### Raspberry Pi Connected to CH340 on STM32F103. Broken Pi and USB interface

I have a 3D printer that's running based on a STM32 chip. Included on the mainboard is a CH340 serial to USB converter. I connected this board with to my Raspberry pi 3 which I powered using the 24v ...
173 views

### Buck converter quiescent current is too high

My circuit uses a LMR50410Y3FQDBVRQ1 buck converter to convert an input voltage from a LiPo battery to a 3.3 V supply voltage. The first batch of the PCB uses the 3.3 V fixed output variant (...
29 views

### Maintaining a current in a circuit connected to multiple DC motors (3.0V) that turn on and off arbitrarily

I have a circuit that is connected to multiple DRV8833 motor drivers. Each motor driver is connected to two 3.0V DC motors. The timing of when they run and stop and how many rotations they perform is ...
16 views

### Buck converter State-Plane Analysis

Do you know how to use state-plane analysis to learn the zero-voltage-switching buck converter? I searched for some papers, but most papers talk about LLC converter. I want to learn the ZVS of the ...
44 views

### TPS541620 Buck converter IC - Feedback loop

I've been designing a POL supply using TI's new TPS541620. This seemed to be a good choice but it being new, it's quite hard to get more support than the datasheet can provide. And unfortunately some ...
114 views

### Is it possible to “stack” the outputs of 2 or more buck converters?

Is it possible to "stack" the outputs of 2 or more buck converters? The buck converter circuit in question I am considering is the 48v to 5v typical example circuit from page 20 of the ...
84 views

### 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 ...
57 views

### Error in compensator for buck

I'm trying to put my ZVS buck converter (DCM) in closed loop. I ran some simulations on MATLAB, and figured that just multiplying the transfer function of the open loop buck by 0.5 gives acceptable ...
84 views

### Design of a Buck Converter with LC Input Filter

I am attempting to design a circuit from an exercise: I am stuck at point (c). I attempted to calculate the voltage and current ripple in the LC filter using the small-ripple approximation, but this ...
109 views

### Buck Converter Inductor current at Steady State

I am trying to learn about Buck converters from the below page. https://www.allaboutcircuits.com/technical-articles/analysis-of-four-dc-dc-converters-in-equilibrium/ Below line is confusing me ...
55 views

### Isolated board design suggestions

First of all thanks for reading this post. I am designing an isolated board for several peripherals for which I need your help/suggestions. The board contains a buck converter (like LM2596) to step ...
39 views

### Buck converter high side switch GND

In Figure 1, I designed a synchronous buck converter using the IR2110S half bridge gate driver integration. However, when I look at the source-GND measurements of the high side MOSFETs in Figure 2, I ...
67 views

### Constant Current of an XL4016 Buck Power Module [duplicate]

Hi have this buck converter : Step Down Buck 9A 300W Converter 5-40V To 1.2-35V Power Module XL4016 I've done my research, read some posts and articles but I'm still quite confused, some say a ...
64 views

### Small signal modelling of buck converter, varying frequency

It seems that the most popular method of voltage mode control of buck converters is by varying the duty cycle. Is this because it is easier to do so because we can set the duty cycle using PWM ICs? ...