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

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Is it useful to think of SMPS input capacitance as part of an LC filter?

I'm at the stage of learning about switched-mode power supplies that I'm focused on understanding the role of input capacitance. Just for background, I'm working with a buck topology for this ...
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1answer
39 views

MCP16301 Step Down Voltage Regulator PCB Layout Validation

I'm looking for some feedback/validation that the layout for this MCP16301 is correct. I'm trying to get 600mA 3.3v Out from 12 input. I'm using the circuit as described in the datasheet on page 23 ...
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2answers
70 views

-5v from +12V input

In my application, I need -5v for OP-AMP application. Load on -5V is 200mA. I have come across various possible ways, as follows: 1) Using TPS5430 as inverting buck boost We are using TPS5430 in ...
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1answer
40 views

Efficient low current buck controller topology

In SMPS there are two sources of loss: parasitics, and the controller. Usually, the load consumes more power than the controller, and the parasitic losses dominate. I have the opposite situation. I ...
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1answer
47 views

Connecting a Volt Ammeter to the input and output of a power supply

I'm working on a mini adjustable power supply that can give me a steady max of 12 volts, 3A and be able to boost to 24V when needed. Therefore, to do so I'm using a MT3608 2A DC-DC Step Up Power ...
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44 views

Current in Buck Converter

In Buck Converter, when switch in ON, Vi(I/P voltage)=Vl(inductor Voltage)+Vo(O/P voltage)when we switch it On, current increases linearly(according to the wikipedia) then Vl=Ldi/dt=constant and Vo(=...
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58 views

What SMPS topology is this?

I came across this SMPS topology that I don't recognize. It looks sort of like a combination of a buck converter and a boost converter, but I can't quite figure it out. I haven't been able to find ...
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1answer
73 views

The function of the inductor in a boost converter [duplicate]

Above is a circuit from a text acts as a boost-converter. It is doubling the voltage. I guess it is doing by choosing a larger C1 than C2? The text says the average voltage across L is zero. And ...
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99 views

Buck converter worked for 1000+ start/stop cycles with power from regulated DC power supply, failed with li-ion battery

I have a project which uses a TI step down converter (LMZ14201) to buck an input voltage (up to 41V) down to a regulated 5V. Until now, I had successfully used an adjustable (regulated) DC power ...
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1answer
63 views

Battery Charger using a buck converter

I'm designing a Lead Acid battery charger with 3 stages. For the 2nd stage (constant voltage stage) as it is written in literature: the voltage applied on the battery must be dependent on temperature. ...
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1answer
35 views

LT3680 switcher output doesn't have regulation under no load

I have a switcher circuit based on LT3680. I implemented the typical circuit shown in the datasheet in a well laid out 4-layer PCB. However, I find that the input voltage is present at the output at ...
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41 views

Making an LM393-based adjustable voltage buck converter

I recently saw this circuit for an LM393-based adjustable constant-current buck converter intended for driving 1W or 3W LEDS and decided to build it. It worked very well, and I was wondering if it ...
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43 views

LC circuit of buck converter in nRF8001 datasheet

In the datasheet of the nRF8001, they specify in the reference schematic (page 51) the LC circuit to use with the integrated DC/DC converter (see below). Why is there a small inductor L5 in series ...
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2answers
53 views

Buck Regulator Supply From Multiple Sources

Hey Electrical Engineerers! I am currently working on making an LED tail light for an older car. Overview of the Taillight Each tail light has 4 inputs connected to it: Park, Brake, Turn, and ...
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40 views

Single Buck Regulator for Multiple Circuits

Currently working on a project that involves 4 separate circuits that light up LEDs on one tail light PCB in an automotive application. Due to the high cost of a buck regulator circuit, we have ...
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1answer
47 views

buck converter, no load start

I've been working with a buck converter since a few weeks, I've tested it with load and it works just fine, but today I've measured the output with no load and saw some unexpected behavior. ...
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1answer
68 views

Remove the load of buck converter

I have a buck converter that is delivering 6A to a load of 3ohm load. I'm measuring the output current and stop increasing the dutty cicle when the current reach 6A, at this moment the output voltage ...
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3answers
436 views

Power MOSFET gets hot while driving Peltier by step-down buck voltage converter

I have a TEC1-12712 Peltier element, which I am driving using Arduino microcontroller through IRFZ44N and buck step down converter (to smooth PWM). Overall, circuit consists of: 12V, 8.5A max DC ...
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55 views

Buck converter control

I'm using a buck converter to power a resistive load, the requeriment I've is to increase the current progressively, to do this I'm using a uC. Converter specifications are: Input voltage: 28V ...
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1answer
61 views

What drawbacks to bucking, then boosting the same current?

Are there any real negative drawbacks - outside of the double drop of efficiency - of DC-DC boosting a power line that was already DC-DC bucked? I'm building a modular system, serially linked through ...
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34 views

What are the risk of overload a inductor in buck converter?

I've a buck converter working at 100kHz simulate this circuit – Schematic created using CircuitLab So far I have tested the circuit for a 4A output current, but I may need to work with ...
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43 views

MPPT using pic16f877a (solar battery charger)

I'm trying to charge some batteries using 12v solar panels. I'm using a pic16f877a for the mppt algorithm(incremental conductance). I have two problems: 1)Current Sensing: I want to use acs712 (5A) ...
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1answer
53 views

Chaining buck converters

I am using these step-down adjustable buck regulators for various purposes (hobby projects and experiments) and they work more or less fine. But I have this little concern - when they convert ...
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1answer
110 views

What's an efficient way to get below the standard 1.25V on buck converters?

So, I purchased a buck converter which was advertised to be able to range down to 0.8V but, as you can probably guess, it only goes down to 1.25V which I understand is the reference voltage for the ...
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1answer
111 views

How do I wire an ebay AC-DC 12v Power Supply Buck Converter Step Down Module

I go a few of these from ebay, but they lacked any kind of instructions and it's not obvious from looking at the circuit-board markings which is the input and output (I guess maybe the holes marked +...
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1answer
34 views

synchronous buck converter with different MOSFETs

do you know if it is possible to use different type of MOSFETs in a syncronous buck converter for the hi-side and the low side switch? How does this improve the converter efficiency? Thank you
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63 views

SMPS buck convrter with PWM controller circuit

Hi there I am designing a buck converter run on PWM circuitry for a uni project to drive a MOSFET switch and keep my output voltage constant. The specs are: input voltage of 20v DC +/- 4 output ...
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1answer
46 views

Power supply - Boost voltage over distances

I'm looking for a good power supply design to boost the DC voltage and convert it to AC so it can be transported over a long distances with low loss. I have drawed a example picture: The only thing ...
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1answer
62 views

Unwanted oscillations and distortions in buck converter

I've tried today to design a very simple and crude 26V to ~12V buck converter. But after testing it in LTspice I've got some weird and unexplained oscillations and distortions. The oscillations ...
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65 views

Buck Boost Driver to switch 2 LED chains

simulate this circuit – Schematic created using CircuitLab I'm working on a project to turn 2 LED strings (each containing 6 HB LEDs). Here is my question. The Buck Boost driver I'm using is ...
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1answer
65 views

Two DC DC converter with different output - In series or parallel?

Source: LiPo Battery (13V - 16.8V) Consumer #1: 5V (RaspPi) ~1A Consumer #2: 12V (variouse) 0-3A (plus ~1A if series) DC/DC step down: two LM2596 Which would be the better solution: LM2596 #1 on ...
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1answer
98 views

How come SMPS regulators doesn't show current limiting circuit?

for example the LM2678-ADJ is a famous buck converter, there are also many others. I have googled and looked through other regulators, there are many schematics in the datasheets of how you make the ...
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68 views

How to control output voltage on a Buck Converter

I'm fairly new to electronics and I have copied the Buck Converter (LM2678) in the picture attached to convert 24V to 5V. After trying it I have actually converted 24V to 9V and my question is if I ...
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1answer
36 views

Synchronous Buck Converter loop function

I have been reading the data of this Buck converter model, but on the block diagram scheme. I don't understand what does the indicated feedback loop do. The buck Convert model is LM5165-Q1 and this ...
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2answers
61 views

TI TPS57160-Q1 step-down converter outputs sawtooth-like voltage at high input voltages

Disclaimer: I have posted this question on Texas Instruments' E2E Community before (Here), but haven't found a solution to my problem yet. In the meantime, I haven't found any way to progress on this ...
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1answer
40 views

Does current flow through the potentiometers of buck and boost converters?

I'm working on a project where I'm replacing the trimpots on a buck converter and a boost converter with proper potentiometers. The new potentiometers will be wired to the converters instead of ...
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27 views

Current drawn from source by buck reg

simulate this circuit – Schematic created using CircuitLab The circuit above is that of a buck regulator that has an efficiency of approx 85%. The input and output voltages are 10V and 3.3V ...
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1answer
70 views

Effect of using two buck converters in series

Are there any limitations of connecting two non-isolated buck converters in series? Just taking the output from the first converter and connect it as the input of a second converter to produce two DC ...
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1answer
53 views

LMR10510 - Simple switcher “breakoutboard” output measures 0V

I have a problem concerning this Simple Switcher found here. I used the design example 3 for the LMR10510Y found on page 17 of the datasheet, however measuring the output pins of the switcher returns ...
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50 views

buck regulator MOSFET turning off for a short duratiopn

I am designing a regulator system using a buck regulalator. The datasheet is - datasheet. Now, the regulator can be configured to switch at 100-500kHz, and this is done using a resistor connected to ...
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2answers
356 views

What is the correct replacement for this mosfet?

I'm trying to repair a broken DC-ATX power supply that I have. After a bit of searching for faults I believe I have tracked the problem down to one of the MOSFETs. I would like to try replace this ...
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92 views

Isolated AC/DC Buck Converter

Why are there no isolated AC/DC buck converters around? For applications < 10W (say 5V/1A output) and mains input (85 - 264VC), is it feasible to use a standard buck circuit but add a 1:1 ...
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1answer
215 views

SMPS Buck converter with PWM circuit

I am designing a buck converter with PWM circuitry for a school project to drive a MOSFET switch to keep my output voltage constant. The specs are: input voltage of 20v DC +/- 4 output voltage of 5v ...
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1answer
56 views

Advice on Buck-Boost Stage

In one of my circuit, the incoming variable voltage(8.5-24V DC) from the source will be first stepped up to 17V using a boost converter. The same output shall then be stepped down to different ...
4
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1answer
108 views

Loop compensation design of buck converter

I am trying to design loop compensation with type-3 error amplifier for a buck converter. I'm a student and very inexperienced in this subject. Please bear with me. Here is the general procedure ...
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0answers
30 views

Determine correct frequency for existing buck converter

This piece of equipment landed in my lap. It is a South African made solar MPPT charge controller. It consists of a controller board with an ATmega88 chip that drives 4 synchronous buck converter ...
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1answer
36 views

LM3405 (buck driver) dropout

I've built an LM3405 LED Driver, which works (seem) well. The LED have a 3.2V of Vf and works at 700mA. The regulator uses an external boost voltage of 3V (from an LDO). Reading the datasheet of the ...
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2answers
54 views

Simple PWM vs Buck Topology for Motor Speed Control

A simple triangle wave generator with a comparator can be used to create PWM that can be fed to a switch for controlling the speed of the motor. Alternatively, by using any buck controller ...
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133 views

Transformerless BUCK SMPS for 1kV->12V

I have a challenge to push 500 Watts (15V) at 100 meters of telco telephone cable (0.088mm2, 28 AWG, 200Ohm/km, 500MOhm insulation). The only way to achieve this is by boosting the voltage up to ...
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450 views

Is Stepping Down More Efficient When Voltages are Already Closer Together?

If I was to use a buck converter to step-down my input voltage would I have a greater efficiency if my voltages are close together e.g. 7.2v to 5v compared to 12v to 5v?