All Questions
Tagged with compensation switch-mode-power-supply
26 questions
1
vote
1
answer
82
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Current regulation compensation SG3524 and right place to place sense resistor
What is the right place to place current sense resistor? As in picture we get traingular wave n position 1, sine wave with highest amplitude on pos 2, smaller sine wave on pos 3 and nearly flat line ...
- 135
3
votes
2
answers
333
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How feedback loop is done in wide voltage range laboratory power supply? TL494 compensation
Hello i would like to ask how is compensation done on switching PSU with wide range variable output voltage (from zero to several hundres of volts). I have succesfuly (I guess) simulate my own design ...
- 135
0
votes
1
answer
716
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DC-DC converter error amplifier output
I am new to DC-DC converter electronics. I was wondering what the output of the error amplifier/compensator looks like.
Is the output of the compensator being driven to the Vref value set on the non-...
- 101
2
votes
0
answers
606
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Trying to perform transient frequency response with LTspice or Microcap, TL494 compensation
I have tried to do Bode plot of my uncompensated plant by myself in LTspice 17.1, but the result looks strange to me. This topic is a follow-on to this one.. I have no clue why it comes with 290 ...
- 135
2
votes
1
answer
1k
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TL494 compensation
I am trying to make a homebrew power supply. It works at the moment, but compensation is not done yet.
Can someone help me to calculate and select the right poles and zeros? VCM is at error op-amp 1, ...
- 135
0
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0
answers
140
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Cancelling optocoupler pole in an isolated voltage mode controlled smps
I am designing a 600W halfbridge converter with a voltage mode controller(TL494). I am using a type 3 compensator with TL431 as shown in the image below:
where:
The capacitor C2 constitutes the ...
- 101
1
vote
1
answer
104
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DCDC booster oscillation because of small drops of input voltage
I'm stuck with this DCDC booster design that shows a bad oscillation output when a little voltage drop is present at the input.
I have already tried to change the inductance to 4.7uH (actually, the ...
- 11
2
votes
1
answer
236
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Why is it easier to make a boost converter stable by feeding back a very small amount of output?
The image below is about peak current mode control for a boost converter. Someone said that it's easier to make it stable by feedback a very small of output like 1/10 Vout (or R2 << R1). ...
- 698
1
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1
answer
765
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Need help understanding error amplifier compensation
This application note (for the PWM controller I am using, UC3825B) details about error amplifier compensation for the built-in error amplifier.
It says it will be compensated to cross 0 dB at (...
- 15
0
votes
1
answer
243
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Can I replace the ceramic capacitor with tantalum?
In the following topology, a 2200nF multilayer ceramic capacitor (SR305E225MAR) is used in the compensation network. Can I replace it with a tantalum capacitor with equivalent voltage and capacitance? ...
- 755
1
vote
1
answer
283
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Phase Margin and Transient Response Contradicting?
I am designing a forward converter that is supposed to work as a pre-regulator for a linear supply. The forward converter is supposed to be able to give output from 4V to 34V and 0 to 5A. While ...
- 180
0
votes
0
answers
118
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How to plot uncomensated loop gain in LTspice
I want to plot an uncompensated loop gain of a dcm flyback dc-dc converter. I know that I can derive the control to output transfer function and then plot the uncompensated loop gain but that just ...
- 180
0
votes
1
answer
107
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Feedback loop design (buck converter): Output capacitance- effective value or nominal value to be considered?
In this TI datasheet of TPS62180, it was mentioned that the LC filter combination should be selected from a set of predefined values. I understand this is usually the case for an internally ...
- 3,156
5
votes
2
answers
810
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Flyback power supply instability issue
I have created a switching power supply:
Input: 230 V AC
Output: 12 V DC, 1 A
Controller: UC3844
Topology: flyback
Switching frequency: ~ 100 kHz
Schematic:
When I start this power supply, output ...
- 5,528
0
votes
0
answers
56
views
Isolated Type 3 Compensator
I'm trying to build a full bridge dc-dc converter and planning to apply a type 3 compensator(voltage mode). When I check the isolated feedback type 3, I've read some comments indicate that it's hard ...
- 319
0
votes
1
answer
94
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Designing a compensator - Control system - Missing value
I would like to determine the transfer function of the following circuit made of TL431. According to the different AN that I have read (and about this subject I really really thank Christophe BASSO, ...
- 2,610
0
votes
1
answer
497
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DC Gain of the System
I'm trying to design a feedbcak loop compensator and I'm following the instructions on power supply cookbook.
Book has calculations for DC gain like equations below:
in my situation Vin: 40V-60V and ...
- 319
1
vote
1
answer
120
views
Stability of SMPS designed for a motherboard
Many books have covered the stability of many configurations of switch mode power supplies and they have given details on how to set the poles and the zeros of the compensator to make the the power ...
- 1,078
1
vote
1
answer
331
views
Non Inverting Type 2 and 3 compensators
I'm looking for the topology and transfer function of a non-inverting type 2 and 3 compensators (PID controller). they are used in CC and CV feedback control in charging/Discharging circuits of ...
- 1,078
3
votes
1
answer
309
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Hybrid Boost-Flyback Stability Issue
I tried to design a step up SMPS to create ~200-300V from a 24V input with an expected power of ~12W max. Since the project is for a hobby, I chose to attempt a hybrid boost-flyback converter to get ...
- 3,586
0
votes
1
answer
455
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Adjustable non-inverting Buck-Boost converter failing right after starting in boost-mode
I am designing an adjustable non-inverting buck-boost converter based on LM5176 chip. Adjusting is done by DAC via feedback network, more on that technique can be found here.
The input voltage is 32V ...
- 134
2
votes
0
answers
1k
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Average current mode control compensation
This is the structure of average current mode control (source here).
Please look at signal \$V_{com}\$ at the positive input of PWM modulator.
For proper operation, in steady state the magnitude of ...
- 1,661
0
votes
2
answers
145
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Why is this Type I compensator phase not 270 degrees?
This is a Type I compensator with a pole at origin. The transfer function between \$V_{in}\$ and \$V_{out}\$ is as follows:
$$ \frac{V_{out}}{V_{in}}= -\frac{R_{2}}{R_{1}+R_{2}} \frac{1}{s (R_{1}|| ...
- 1,661
0
votes
1
answer
92
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How the effect of the output inductor is minimized and filter offers only single pole by current mode control?
In this application note "Switching Power Supply Topology Voltage Mode vs. Current Mode", page 2, Current Mode Control section the author claimed as follows:
Since the Error Amplifier is now ...
- 1,661
6
votes
1
answer
1k
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 ...
- 897
8
votes
2
answers
4k
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Why do we compensate PWM controllers?
I have been studying switch mode power supplies for a while. I have understood the working principle of several common topologies But there is a detail in the control circuit structures which I still ...
- 14.2k