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

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22 views

Help with designing negative part of Dual-Sided SMPS

For a project of mine, I'm trying to make a dual-sided SMPS that has independently variable positive and negative supply rails, current limiting, short circuit protection, etc etc... My current plan ...
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1answer
40 views

Inverting buck-boost vs. positive buck-boost

Should I use an inverting buck-boost or a positive buck-boost topology? Input voltage range = 19-22VDC, Output voltage range = 10-56VDC, Application = LED driver The app not I have says the ...
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0answers
27 views

Help with PFM with PID Control on dsPIC30F2020 (Pulse Frequency Modulation)

I'm using the dsPIC30F2020 trying to do a project that compares and contrasts PWM and PFM bucks converters. I have the PWM buck converter working perfectly. So for the PFM I used the exact same code ...
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2answers
72 views

Best way to power a 3.3V circuit from 3.3V-to-5.0V source

I'm working on an add-on board that needs 3.3V power (~500mA) and should take power from its host board. The host can operate at 3.3V or 5V and I'd like to avoid using jumpers that would require the ...
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0answers
34 views

Buck Converter with lead battery source

I have a buck converter using the ST1S14 step down converter. The design was tested with a AC to DC converter source in the lab. With 12V DC supply the circuit performed well delivering currents upto ...
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0answers
49 views

Improving PCB layout for regulator circuit

I've made a layout around an Allegro A4490 triple buck regulator, with four optimization goals: minimize loop area/change in area when switching keep the ground attachment of the input and output ...
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1answer
61 views

Buck regulator AOZ1014 getting burned

I am analyzing a buck regulator circuit as shown in following figure. link for datasheet given here: http://aosmd.com/pdfs/datasheet/AOZ1014AI.pdf I have few queries in schematic: Q1. In above ...
2
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1answer
54 views

Switching Regulator Current Conversion

Can a switching regulator deliver more current than the input side can provide just at a lower voltage? For example if I have a 10V 1A (10W) input source going through a switching regulator (100% ...
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1answer
25 views

LM2596 inverting mode to generate -5v

I am trying to use an LM2596-adjustable to make an inverting Buck-Boost power supply as per below: The circuit requires a voltage divider that is used to adjust the output voltage. In the diagram, ...
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2answers
100 views

MOSFET source to drain Current

Since similar kind of questions being asked before it.. They doesn't clarify how one can use it in circuit. I'm aware that a MOSFET is a bidirectional device and in one direction current can flow ...
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3answers
70 views

Can I get constant current at the output of a buck convertor (to drive a LED)?

I want to drive a LED with a buck converter circuit as shown in the schematic below. In order to keep the circuit simple, the system will run open-loop (i.e.; there won't be any voltage or current ...
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0answers
57 views

Power micro LED's from 5 Volt USB

simulate this circuit – Schematic created using CircuitLab I'm working with this set of LED's: Link here: 30 Ft Led wire I measured the draw for the entire string at about 170 ...
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1answer
59 views

Buck and Boost drivers for LED

Many of the newer bike lights use LEDs. Although I understand basic electronics it has been some years since I learned electronic theory. Although I understand the basics of buck and boost drivers I ...
0
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1answer
41 views

Questions concerning Solar MPPT tracker

I am building a solar MPPT tracker. First of all: what I understood from MPPT is that MPPT units transfer the maximum power available from a solar panel at that time to the load. This can be done by ...
1
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1answer
57 views

Maximum Power Point Tracking Duty Cycle for a Buck Regulator

I'm currently building a 10W high voltage (~50V-100V) Maximum Power Point Tracking (MPPT) buck regulator on the side for educational purposes. For the time being, the output is tied to a load. ...
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0answers
29 views

AC to DC converter for 5V USB Charger [duplicate]

I have been looking around to understand how phone chargers can pump out 1-2 Amps of current through the USB port in such a small package. I am sure they do use a transformer for isolation. One of ...
3
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2answers
138 views

Combining LDOs in an effort to increase current

Is there any way to combine 2 (or more) similar LDOs with fixed output voltage so the total output current would be increased? Buying another LDO is possible but I have a large stock of 1A LDOs and I ...
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0answers
50 views

Digital Buck Control

I wish to emulate a voltage mode buck control using FPGA. My idea was to obtain a discrete state space equation that can be implemented digitally. At first I calculated to the buck small signal open ...
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2answers
79 views

Inverting (Buck-boost) converter polarity problem

I have trouble understanding something in the circuit below. It is inverting converter, seems quite easy, but the part I don't get is when the switch is OFF we have forward-biased diode, i.e. plus on ...
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1answer
29 views

best way to adjust/set SMPS comp / compensation parts

I’m having difficulties with settings the right values for the comb / compensation for some SMPS circuits I’m working one. Is there a good way to set them right? To make sure of stable operation in ...
1
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1answer
60 views

Help with high side driver

I am building a non-isolated buck converter with a N channel MOSFET(2SK4017), I am using the FAN7382 High and low side gate driver. I just want to verify if my wiring is correct before I construct the ...
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0answers
47 views

Electric vehicle battery balancing

I need to choose a method for my project in for active balancing of Li-Ion batteries for EV application. I read a paper for this purpose: "A Review of Passive and Active Battery Balancing based on ...
0
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1answer
70 views

Relationship between switching frequency and controller's crossover frequency in buck SMPS

Context: tuning the control loop of a buck SMPS. I specicifally have a TI TPS40200-based circuit in mind, but I think this applies to SMPS design in general. Quoting from Type 2 compensation network: ...
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2answers
110 views

Charging supercapacitors with Buck converter. Do I need to cut power once charge is reached?

I am trying to build a supercapacitor charger, and as I don't particularly have a good handle on the risks of such a thing, I'm hopping on here to give some information. I am using a buck converter ...
-3
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1answer
113 views

How to the calculate the value of capacitor placed in series with transformer to avoid flux walking in a buck converter? [closed]

The dc value of current in primary increases(in -ve direction) as time passes, so I need a capacitor in series with transformer, but don't know what value capacitor should I use. filter capacitor = ...
3
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1answer
114 views

Transistor Level Shifting in Buck-Boost Converter

Ive been reading some of the LT application notes on Jim William's Analog Circuit Design book, and there's something I don't quite understand. I'm attaching a scan of the circuit in question. The ...
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1answer
57 views

Is it safe to use a non-isolated buck converter for an LED driver?

I am making a commercial LED lamp. I am using a non-isolated circuit. I am using buck converter. Is it safe? Can I use a buck converter after the bridge rectifier?
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4answers
131 views

Does a “Buck Step Down Voltage Regulator” provide constant output voltage regardless of input voltage?

I've got a small solar cell panel rated at 20V on a good sunny day. I need to regulate this down to 13.8V to charge a lead battery. Can I use a "Buck Step Down Voltage Regulator" for this? I'm ...
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2answers
121 views

Can I power Ardiuno using buck converter IC 3485 or any other buck circuit?

A buck circuit lowers the voltage by generating pulses at a certain duty cycle. Is it okay to give this pulsing voltage to Arduino? Can Arduino work normally with this? I have 12V battery and I want ...
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3answers
232 views

Spikes in Inductor Current : Buck Converter

What could be the reason of such spikes in inductor current at each Switch ON-OFF. ?? This spikes are also getting affected in load current. Please help me to reduce / remove this spikes. ( ...
2
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2answers
229 views

LM3485 current limiter (\$R_{adj}\$) value selection

I have what I believe is a working buck converter design centered around the LM3485. It's intended to be a Raspberry Pi power supply. The schematic is at Pi Power schematic, which I copy below. ...
0
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3answers
112 views

How are these RC values calculated in this buck converter?

Buck converter: LTC3824 The datasheet says: VC (Pin 4): The Output of the voltage error amplifier gm and the control signal of the current mode PWM control loop. Switching starts at 0.7V, and ...
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0answers
75 views

powering a micro in sleep mode

I've got a setup that will spend 1/3 of its time running a few servos (figure up to 1A @ 5V), 1/3 running sensors / other (<300mA @ 3.3V), and 1/3 of its time sleeping with just the watchdog ...
0
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1answer
88 views

Power Supply Design: Am I after DC-DC Controllers or DC-DC Converters?

I'm trying to design a variable dual rail power supply, which has an unregulated input voltage of ~11V and a maximum output current of 1A. I want to have a 5V/12V/20V positive and negative output. ...
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4answers
354 views

How to drop 240V DC to 5V DC

I would like to drop a 240V DC voltage to a 5V DC voltage to supply electronic. The 5V stage needs less than 5mA in current. The solutions I looked at are: Resistor divider (Not really ...
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2answers
94 views

How to theoretically determine ESR of a capacitor and DCR of an inductor for a buck converter?

How can we determine ESR of the capacitor and DCR of inductor theoretically in the design of buck converter, without using an LCR meter?
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2answers
242 views

using multiple buck step-down voltage regulator modules to convert 50-400V DC to 12V DC

I would like to generate ca. 12.5V, 8-10A, DC power from an incoming voltage between 50 and 400 DC that has been rectified from 3-phase AC coming from a brushless motor acting as a dynamo. I will ...
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0answers
51 views

Buck converter effect on amp draw

It was my understanding that the circuit will only draw the current thats needed - a 1A servo will only draw 1A. I have a rather large project so I am using a 24V 5A rated wall adapter, and using ...
1
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1answer
113 views

What is the best way to power both my 5v 16 x 16 Neopixel matrix and the 9v Arduino that drives it? [closed]

I have 4 Adafruit 8x8 Neopixel matrices interconnected to form a 16 x 16 matrix driven by an Arduino Mega. Right now I am using two different power sources to power the matrix and the microcontroller. ...
6
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5answers
968 views

Extract 5W low voltage power from 3000W high voltage source

I have a solarpanel array that generates 600V, 5A (3kW). I want to create a small electronic unit to measure the DC current and voltage and transmit this wireless. For this I have an electronic board ...
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0answers
49 views

Battery Charge Regulation Application

I'm building a switched mode power supply unit to take electrical energy generated by solar panels and store it inside a Lithium Ion battery pack. Some specifications: 1. The solar panel open circuit ...
0
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2answers
56 views

Getting closer to figuring out my battery requirements

I have been doing research for at least a week and am still a bit confused, but think I am getting to the point where I am close. I need to power 5V 3-5A. Some days this power source will hook up to ...
3
votes
4answers
650 views

How to make a step down DC-DC converter fail safe?

I'm planning to power some high power colored LEDs with a buck converter, using a microcontroller to control the switching to maintain a constant current. I'm also considering a simpler, switched ...
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0answers
94 views

Designing an efficient PSU

I am designing a PSU capable of producing 5 watts @ 5V 1A. The design will power about 12 RGB LEDs (totaling about 400mA @ 5V) and a audio class D 1.4 W amp. Space is no issue but efficiency and cost ...
1
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1answer
74 views

AP3431 burning up with no load on it

EDIT 1: I was able to get it to work, but I am not at all sure what happened here... I decided to build this circuit again - exactly the same layout and parts (see original question below). As soon ...
1
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1answer
111 views

Strange oscillation in buck converter (AP3431)

I am having a lot of trouble getting AP3431 to work reliably. The converter works properly for about 30 seconds, and then oscillations begin, with brief periods of normal function. Here is how it is ...
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0answers
151 views

Suitable switching/buck regulator - Vin = 24V and Vout = 5V and max current = 0.4A

Due to a sudden change in design requirements with regards my circuit supply voltage I'm looking to change my voltage regulation on my circuit from the classic LM7805 linear voltage regulator to a ...
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3answers
299 views

Effect of using buck converters in parallel

What is the effect, downside or purpose, if any, of using buck converters in parallel? For example, to connect the Vout and Gnd together on two converters. Could this be used to increase the current ...
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0answers
40 views

How to configure LTM4641 buck converter demo board

When I put a load greater than some small Ampere, about 5mA I think, the board shuts down. Vout goes from 4.97V to zero in about three seconds. I want this to deliver 10A load at 5V. The Manual for ...
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1answer
198 views

Switched Mode Power Supply : Voltage Mode Control and Error Amplifier Output

I am trying to understand how regulation happens on Cycle-Cycle basis in the case of Voltage Mode Control (VMC) and Current Mode Control (CMC). I understand that in the case of VMC, an error ...