All Questions
Tagged with compensation dc-dc-converter
20 questions
2
votes
1
answer
118
views
Buck-boost output drops when loaded
The LTC3566, a PMIC intended for battery and USB supplied applications, integrates a battery charger, a power path and a buck-boost converter. For my board, I copy-pasted the schematic found on the ...
- 179
1
vote
1
answer
188
views
LTC7803 Buck Converter Current Mode Compensation
I wanted to design a step-down converter using the LTC7803. Goal is to have a 5V, 0-2A output with an input voltage range of 10-30V. Switching frequency is set at 1MHz. As shown in the LTSpice picture ...
- 101
3
votes
2
answers
633
views
Buck Converter Compensation and Transient Response
I am trying to compensate a buck converter. I've set up an averaged model of a buck converter in LTSpice.
Here is a picture of the simulation. The B3 voltage takes into account the gain from using a 5 ...
- 101
0
votes
1
answer
716
views
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
0
votes
0
answers
140
views
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
views
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
views
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
4
votes
1
answer
159
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Output voltage not stable - What is compensation with respect to DC-DC (buck converter)?
EDITS:
Input voltage range: 24V to 48V.
Changing the load current from 0.38A to 1.018A increases the mean output voltage from 12.779V to 13.26V. The supply should be producing 12.5V.
I'm using this ...
user220456
0
votes
2
answers
172
views
How can gain and phase margin be used to assess stability of SMPCs as for most of the cases (except buck), they always have a Right Hand Zero?
I was going through this Operational Amplifiers, Theory and Practice by James Roberge. On Page 146, it is mentioned that for systems that have negative feedback at low or mid frequencies and that have ...
0
votes
1
answer
497
views
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
0
votes
0
answers
148
views
How to determine these resistors in 2-pole 2-zero feedback loop compensation
I'm trying to build a 2-pole 2-zero feedback loop compensation for controlling a full bridge dc-dc converter. It's my first time doing this and I'm following the book power supply cookbook. Book is ...
- 319
0
votes
0
answers
42
views
Slope compensation of MAX17498
I want to use MAX17498 in boost mode.
I have a problem setting the slope compensation. The slope (as I understand) is the gradient of the inductor's current ramp. The unit is [A/s] or [A/us]. However,...
- 625
1
vote
0
answers
526
views
Type 3 Compensation on Full Bridge DC-DC Converter with SG3525
I'm trying to build a 48V-400V full bridge dc-dc converter. I'm using sg3525 as pwm IC and trying to get isolated feedback from output and planing to do it with TL431.
When I study on it people are ...
- 319
2
votes
1
answer
2k
views
Loop compensation of a Buck Converter
I have a buck converter. TPS54260
Vin = 7V-20V
Vout = 5V
Iload=600mA.
I realise that there is a similar question in this forum but I was not able to get clarity.
I want to understand what do you ...
user220456
0
votes
1
answer
607
views
DCDC converter load step and phase margin
When applying load step to a DCDC converter we can approximate the phase margin from the presence/absence of oscillation and the crossover frequency as well from the response time.
The question is: ...
- 255
0
votes
1
answer
931
views
Design of compensator type 2 for current mode control of boost converter
I have designed a boost converter with peak current mode control in PLECS. I have used the method of k factor approach to design the compensator.
The Bode plot transfer function of the power stage is ...
- 311
2
votes
0
answers
1k
views
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
views
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
1
vote
1
answer
289
views
The Frequency Compensation of LT1683 in a DC-DC Converter
The fig. 10 of Jim Williams's article presents a 2A laser current source circuit using the LT1683. I am confused about the frequency compensation circuit of fig. 10 (pin 12 Vc of LT1683). The page 8 ...
- 35
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