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

learn more… | top users | synonyms

2
votes
5answers
376 views

What does a buck converter do with the energy that a linear regulator would otherwise waste as heat?

I've been reading for hours about how switching regulators work but I'm still unable to understand what it does to keep the power equity between the input and the output (ignoring internal losses). ...
0
votes
1answer
22 views

Buck Regulator IC Markings Identification

I am looking at some type of Buck Regulator chip; 12VDC in-5.0VDC out; 20-Lead, 3mm x 4mm GFN (6-leads, 4-leads, 6-leads, 4-leads; the text on it is: line 1: < 418 line 2: LGCC line 3: B824 Is ...
-2
votes
1answer
74 views

How to increase output current of a circuit? [closed]

I have prepared a portable charger using Texas instruments ptn78060was 5V regulator and input voltage is 9v non rechargable battery.But current output is very small around 90mA. What should i do to ...
1
vote
3answers
84 views

What can cause output voltage of DC-DC Switching regulator(AP6502) to drop when load is applied?

I am using a DC - DC switching regulator to provide a LOAD with regulated 5V. I have followed the reference ckt provided in the datasheet but when I upload a load greater than 1A the output voltage ...
0
votes
2answers
65 views

What can cause the output voltage of a buck converter to drop (apart from high current)?

I am using the LTC3388-1 buck converter to provide a microcontroller with a regulated 1.8V voltage. I use pretty much the reference circuit as seen in the image. When I disconnect the ...
2
votes
2answers
43 views

Efficiency Curve of Buck Regulator

Below is the efficiency curve for the TI TPS53513(datasheet). Can someone explain what causes this characteristic efficiency curve? It seems to be similar to the one for other regulators as well. Why ...
0
votes
1answer
74 views

Simulating IR2104

I have this simulation set up in Every Circuit. It can be viewed here: http://everycircuit.com/circuit/5875415639916544 For right now I have turned off M3 by jumpering M3's gate to the ground nearby. ...
2
votes
0answers
80 views

DC 5V USB to replace AAA-battery source: down converter

I have a portable lithium battery-powered speaker which takes auxiliary sound input from a single AAA-battery powered pocket radio. The speaker includes a USB port for charging source devices: I ...
0
votes
1answer
46 views

how to calculate PWM duty cycle for led driver

I am trying to design a constant current led driver. I know the peak and the holding current range for led driver How would I find the PWM duty cycle based on the current that I need to control? ...
0
votes
0answers
57 views

inductor selection for DC DC

I am using a buck conv rt8298. My load is abt 5 amps. Input is 12v and output is 5v. I selected an inductor of 8.2uH. The formula tells abt 3.4uH. And sometimes it does not work. Just becos I choose a ...
2
votes
1answer
71 views

Buck converter design problem/confusion

I have problem with designing buck converter. I have tried to design it by using instructions from this site: Buck converter And here are my parameters: V input - 72V max V output - 12 V ...
0
votes
0answers
20 views

how to drive field winding with Buck_Boost?

In the picture that is shown as a Figure 1 obviously there is a resistor functioning as a load, and it's current(Io) as a feedback to the semiconductor (IGBT) in order for it to switch the mentioned ...
0
votes
0answers
23 views

buck boost and exciting synchronous generator

I have a Buck Boost converter for exciting a synchronous generator. the thing is that there is a load in the buck boost converter as shown in Figure 1 , everything is working good. what i want to do ...
0
votes
1answer
52 views

Calibrating buck LED driver by altering Vsens

Many switch mode buck LED drivers use a current mode scheme with a sense resistor back to a Vsens or Current Sense input on the chip. A good example is the LM3404. Here's the typical use circuit: I ...
0
votes
1answer
47 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 ...
1
vote
1answer
77 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 ...
1
vote
0answers
73 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 ...
1
vote
2answers
84 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 ...
0
votes
0answers
44 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 ...
1
vote
0answers
57 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 ...
0
votes
1answer
73 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
votes
1answer
81 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% ...
0
votes
1answer
77 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, ...
1
vote
2answers
176 views

MOSFET source to drain Current

Similar kinds of questions have been asked before it but they don't clarify how one can use this aspect in circuit. I'm aware that a MOSFET is a bidirectional device and in one direction current can ...
1
vote
3answers
75 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 ...
0
votes
0answers
72 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 ...
0
votes
1answer
69 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
votes
1answer
77 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
vote
1answer
80 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. ...
0
votes
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
votes
2answers
151 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 ...
0
votes
0answers
54 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 ...
1
vote
2answers
127 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 ...
1
vote
1answer
39 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
vote
1answer
76 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 ...
0
votes
0answers
56 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
votes
2answers
68 views

freechargecontroller.org. The blocking diode of the MOSFETS

I am looking at a schematic for a solar charge controller: http://freechargecontroller.org/images/a/ab/Charge_controller_4_04b.pdf My question is about the MOSFETS M1 and M2. The data sheet for ...
0
votes
1answer
89 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: ...
0
votes
2answers
130 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
votes
1answer
133 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
votes
1answer
139 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 ...
0
votes
1answer
72 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?
1
vote
4answers
153 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 ...
0
votes
2answers
147 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 ...
0
votes
3answers
313 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
votes
2answers
244 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
votes
3answers
125 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 ...
0
votes
0answers
79 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
votes
1answer
107 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. ...
1
vote
4answers
536 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 ...