All Questions
63
questions
0
votes
3
answers
83
views
How can a current probe avoid saturation?
It is a buck converter, And I want to know how current probe can avoid saturation.
Turns ratio is 1:1000. And DC makes transformer saturation.
So... How can probe avoid saturation?
- 15
3
votes
3
answers
806
views
Input impedance of a buck converter
Is there an approximate formula for calculating the minimum value of the input resistance (or impedance) of a switching regulator? I found several formulas but can't figure out which one to choose. I ...
- 61
0
votes
1
answer
83
views
Reverse current into DC/DC or LDO
Suppose we have a generic scheme like this in figure, in order to protect the inputs of a microcontroller or logic gates from overvoltage essentially. For instance now we're applying 10 V at the input,...
- 61
0
votes
1
answer
94
views
How to divide 12V/15A buck converter output into two outputs with the same specs? [closed]
I am currently working on a project to build a mini-atx pc for a rover. Heres a simple schematic of it :
The picoPSU Atx connector takes in 12V DC with a max of 15A peak and the zotac gpu 12V DC with ...
1
vote
1
answer
73
views
Power dissipation formula
Is the below formula, present on page 26 of this buck converter correct to use?
Or should I use the formula mentioned in the 3 paragraph of this accepted answer?
- 1
0
votes
2
answers
155
views
How much current should a switching regulator consume on its own?
With your help on stack exchange, I finally finished assembling my first LM5143QRHARQ1-based buck converter! And it works! It does output 7V (well 7.03V) The only problem is that it consumes around 0....
- 411
0
votes
2
answers
86
views
OVP threshold for this converter
Here, this Boost converter, says that it can boost the input voltage from 2.5 V to 10 V.
My input is from a 7.4 V, 7.5 Ah battery. Output is 9 V. The maximum load current is 3 A.
Ideally, for my OVP ...
user220456
1
vote
1
answer
238
views
What happens if the Input voltage and the output voltage are same in a boost converter?
I'd just like to know what would happen if the Input voltage and the output voltage are same in a boost converter. I have a feel that it might not work.
But would like to understand the effects that ...
user220456
0
votes
1
answer
63
views
How current gets separated in multiple SW pins in buck converter?
In some high current buck converters, there are multiple SW pins for output current. How the current gets divided between them?
Example, lets consider a buck convertor has 5 SW pins and sourcing 30 A ...
- 543
2
votes
2
answers
2k
views
Buck converter with UC3843
I am building a simple buck converter circuit with a current-mode control IC, the UC3843.
In the application note of the UC3843, a sample circuit is given:
I am completely clueless about how these ...
- 29
0
votes
3
answers
64
views
Current and voltage value before inductor pin in buck converter
In buck converter we know that pure DC current will be after inductor pin. But what will be the current/voltage value before it.
Let’s take an example, the buck converter circuit with 12 V input to 3....
- 543
1
vote
0
answers
55
views
Boost converter output voltage drops
I'm using an MIC2251 (MIC2251-1YD5-TR) in a design to boost a lithium battery (3.6V-4.1V) to 5.4V for powering a small camera peripheral that requires a typical draw of 80mA. I expect that the worse ...
user220456
1
vote
2
answers
116
views
How to calculate the maximum output current of an LTC3440?
I'm trying to make sense of the datasheet of the LTC3440. I can't find how to calculate the maximum output current and on what it depends.
There is an IOUT(MAX)BURST formula for the burst mode on page ...
- 169
0
votes
0
answers
30
views
How to change from HyperLight Load mode to forced PWM mode
In the MIC33M650 step-down module, is there a possibility/workaround to deactivate the HyperLight Load mode? Or decrease the threshold of the current needed to activate forced-PWM mode?
user220456
1
vote
2
answers
68
views
Output load current less - DCDC Converter [closed]
I'm using this Boost converter. 3.6V to 12V with a load current 300mA. 10uH is the inductor used.
But I am only able to get a maximum load current of 120mA. What might be the reason?
user220456
4
votes
1
answer
216
views
Switching frequency data not available
Why do some dc-dc buck or boost converters do not have the switching frequency value in their datasheet?
For example: Link does not have switching frequency ?
Is it possible to get power dissipation ...
user220456
16
votes
4
answers
5k
views
What is the difference between a linear regulator and an LDO
Can someone tell me what the difference between linear regulators and LDOs is?
From what I have read and understood, it is that linear regulators and LDOs don't use switching elements, but I think ...
user220456
0
votes
2
answers
236
views
What is the formula or any method to calculate the value of the output capacitor and inductor in a buck converter
I have using a buck converter whose output is 5V and 1A.
Can someone tell me whether these is any formula to calculate the value of the output capacitor? Like, without involving the switching ...
user220456
1
vote
0
answers
126
views
Inductor saturation current
I'm trying to determine an inductor's saturation current, I use a PWM with a gate driver (TLP250) and a 0.4Ω sense resistor at the source which I probe across to capture the current waveform.
I ...
- 41
0
votes
0
answers
28
views
power available to a DC-DC step down atached to an ac power adapter
I have an AC-DC power adapter with output rated at 3.42A @ 19V and a Step Down Buck converter Xl4015 rated to manage up to 5A with 96% efficiency conected to the power adapter output.
What is the ...
0
votes
4
answers
384
views
How much current is available with a buck converter? (re: 20V/5A to 5V/20A?)
I've been trying to research this as much as possible but I'm still a little confused.
If I'm using a PSU rated for 20V / 5A, can a typical buck converter output 5V / 20A? (assuming 100% efficiency ...
- 481
0
votes
1
answer
80
views
Why is my switching frequency so abnormal?
I am using this Buck Converter 2A part.
I am giving an input voltage of 3.3V to get an output of 1.2V for a switching frequency of 2.25MHz.
I am giving different load currents of 0A, 0.2A, 0.5A & ...
user220456
3
votes
4
answers
3k
views
Output capacitors of DC-DC converters
I am trying to understand what type of output capacitor is a better option.
Suppose I require a 10uF output capacitor at the output of the buck converter, which one should I pick - aluminum ...
user220456
0
votes
1
answer
588
views
How to find the minimum and maximum voltage of this buck converter
I am using buck converter. 3.3V output & 2.5A part with 2.1MHz switching frequency.
I am powering my microcontroller with this 3.3V output. So, I'd like to find the output voltage tolerance of the ...
user220456
0
votes
1
answer
1k
views
LC filter of buck converter
Can someone explain me intuitively on why the LC filter cut off frequency should be very less than the switching frequency of the buck converter?
What is the reason and why can't it be higher than the ...
user220456
0
votes
1
answer
517
views
Buck converter output LC filter phase difference
I was going through a few buck converter questions in this forum to understand deeply about the circuit and I found this question. However, I am not focused too much on the ripple right now. But when ...
user220456
1
vote
2
answers
1k
views
What causes harmonics in DC-DC Switching converters like Buck and Boost Converter
Can someone tell me what and how the harmonics are caused in the DC-DC Switching converters?
I tried to read this, but I am not understanding. Can someone please explain in simple terms
user220456
1
vote
1
answer
352
views
Buck Converter Switching Loop Area in Layout Should be small
I have seen recommendations in the datasheets of buck converters, that the switching loop area should be as small as possible. Can someone help me on what would happen if the switching area is large ...
user220456
0
votes
1
answer
660
views
Buck Converter Voltage waveform at the free wheeling diode cathode and anode
I am trying to understand the voltages at the free wheeling diode's cathode and anode in a buck converter.
During the ON-state (as in the above circuit diagram), I assume the voltage at the diode's ...
user220456
0
votes
1
answer
80
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 ...
user220456
1
vote
2
answers
1k
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 ...
user220456
2
votes
2
answers
1k
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, ...
user220456
0
votes
2
answers
143
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 ...
user220456
2
votes
1
answer
734
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 ...
0
votes
1
answer
88
views
How to set the boost output voltage in this IC?
I want to use this boost IC to drive an LED string.
I have 9 LEDs. 300mA forward current and 3V as typical Vf.
Can someone guide me on how to set the output voltage of the LED string using that IC?
user220456
2
votes
1
answer
272
views
Buck converter current
I have this synchronous buck converter.
Input voltage - 8.7V
Output voltage - 5V
Switching frequency - 350kHz to 450kHz
Output load current is 2A
Schematic:
I have an input capacitor of 68uF and an ...
user220456
0
votes
1
answer
423
views
When and how does a buck converter behave in a boost converter mode?
My question is with reference to this answer for this previous question.
The answer states that a buck converter will behave in a boost mode for some cycles during light load or no load condition.
Can ...
user220456
2
votes
1
answer
418
views
Buck converter problem
I have this buck converter - BD9G201EFJ-M
Buck converter specifications:
Input voltage - 18V to 32V
Switching frequency - 300kHz
Output voltage 9V
Load current - 0mA to 200mA maximum.
I am ...
user220456
4
votes
1
answer
902
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 ...
- 45
2
votes
2
answers
1k
views
Understanding Buck Converters and Solar Panels
I have a solar panel rated at 5V 80mA and want to increase the output current significantly higher to around 500mA and decrease the voltage to either 3V or minimum of 2.7V, how can I go about this?
I ...
- 81
0
votes
2
answers
1k
views
Limit charging current to a smartphone
I'm using an LM2596 buck converter set to 5.0V to power a bunch of stuff among which is a smart phone.
My total consumption is around 1A excluding the phone. I'm not really sure what will happen if ...
- 930
0
votes
3
answers
1k
views
Buck converter source current draw
I'm doing some calculations for a system that is going to use a few buck converters. I need to make sure that the battery will be able to feed enough current but I'm not 100% certain how power on the ...
- 930
0
votes
3
answers
395
views
Which is more efficient: A much larger than needed step-down voltage converter, or one rated closer to the actual load?
I'm designing a custom audio system for my electric motorized pedicab. The motor of my cab runs on a 48 V 33 Ah battery, and I have planned to use a 48 V to 12 V step-down converter to simultaneously ...
2
votes
2
answers
6k
views
Torque and speed control of a DC motor
I'm new to electronics and this is my first post so please be patient with me.
Introduction
I am required to design a rehabilitative exoskeleton-like knee-brace to assist sit to stand, I have faced ...
- 21
0
votes
0
answers
45
views
TPS562208DDCT current problem
I have attached a PSU design which I have created. The input voltage is between 12 and 24V DC.
The first stage creates an isolated output voltage of 7V that is then fed into the two TPS562208DDCT (...
- 51
1
vote
2
answers
157
views
Modifying a buck converter for lower current rating
I have been learning about buck converters and I think I understand the principle of their design. However, I am unsure of how a current rating would be calculated for a particular design.
The ...
- 13
0
votes
1
answer
494
views
How to increase current output of capacitor bank with buck booster?
I'm pretty novice when it comes to electronics given that my background is in mechanical engineering. But I am trying to design a circuit that can take a 5V (almost 0A current) to charge a capacitor ...
- 11
0
votes
2
answers
328
views
Current relationships across a voltage step down convertor
This question arose from a conversation over the weekend and we tied ourselves in knots trying to get to the bottom of it. I didn’t have time to put a simple circuit together so it would be great to ...
- 105
4
votes
1
answer
3k
views
How does this current limiter work? - and why doesn't it?
I have a generic Ebay DC-DC buck converter, and the current limiting circuit is not working. I find that such devices often suffer from this issue, so I figured I'd reverse-engineer it in hopes of ...
- 1,465
0
votes
5
answers
869
views
Can the output current of a buck converter be more than the input current?
I want to power a bulb from solar panel (17 V, 0.9 A) but due to low resistance (2 Ω) of the load I have to reduce the input voltage to 5.5 V @ 2.75 A for maximum power.
I am using a generic buck ...
- 646