Questions tagged [compensation]
The compensation tag has no usage guidance.
66
questions
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28 views
Controller and compensator
What is the difference between controllers and compensators
While searching for answer the most prominent answer I got was that compensator have magnitude=1 and is used to make sure the system ...
0
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1answer
70 views
Poles and Zeros of a Transfer Function
I am trying to understand the physical meaning of poles and zeros of a transfer function. Can someone help me how to understand the Figure 2b in the link below?
What does the height of the cone ...
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1answer
62 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 ...
0
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4answers
88 views
Negative feedback and op-amp poles
I'm trying to get a better understanding of frequency compensation for op-amps. I'll start off with a very specific questions and then get into the context. For a certain op-amp, open loop gain is ...
3
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1answer
77 views
Constant-gm bias circuit
I am doing a study on Improvements in biasing and compensation of CMOS opamp.
Do you guys know how to come up with the equation for RDS4C ?
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0answers
79 views
opamp constant-gm bias circuit
I try to incorporate the constant-gm bias circuit (Figure 6 in Improvements_in_biasing_and_compensation_of_CMOS_opamp) into the PFC (positive feedback frequency compensation) opamp, but it resulted in ...
0
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1answer
92 views
Analog implementation of imaginary roots in a transfer function
I have a simple boost converter, and from multiple papers I've read through, a Type 3 Compensator is recommended. I designed one in Matlab/Simulink, and it reacts very quickly. The problem is, when I ...
1
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2answers
96 views
Compensation capacitor(s) in instrumentation amplifier
I wonder whether the discrete 3-opamp instrumentation amplifier requires any compensation capacitors:
simulate this circuit – Schematic created using CircuitLab
Is it in general recommended to ...
2
votes
2answers
427 views
Crystal compensation for temp and voltage
Introduction
I'm toying with the design for a fail-safe wall clock controlled by multiple 32.768kHz crystal oscillators. I'm currently reading about compensation.
Compensator from literature
From ...
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2answers
71 views
Emitter-coupled logic operation
For the operation of emitter-coupled logic and sedra smith book,
1) Compared to CMOS, why ECL is the faster logic family given that it requires so many transistors to propagate to output Y (T5 ...
0
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1answer
41 views
Static VAr Compensation
I have to design a 3 phase Reactive Power Compensation System with using only reactors, no capacitor is needed. Total capacity is 505kVAr, but 475kVAr will be done with contactors, rest (30kVAr) will ...
0
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3answers
301 views
Why is frequency compensation required here?
Circuit requirements:
DC voltage gain: 50dB
Unity gain bandwidth: 50MHz
Phase margin: 45 deg(60 deg is recommended).
The circuit is completely symmetric, so M1=M2, M3=M4, and M5=M6. Therefore the ...
0
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0answers
51 views
How to design a slope compensation circuit for a boost converter having different output levels at different input ranges?
I am working on a non-isolated boost converter, has 30khz switching frequency and uc3842b is used to implement peak current mode control.
Three phase ac after rectification is applied as an input to ...
0
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0answers
174 views
Design of a lead compensator with root locus in matlab
For the transfer function G(s), I tried to design a lead compensator for the function to have a response to the step with the following specifications: Overshoot= 10%; Ts (2%) = 5s.
When I simulate ...
0
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0answers
76 views
4-20mA current loop - transmit sensor reading
I am working on design loop current transmitter- to transmit reading value from thermocouple sensor using below design. I measured co-junction temperature using NTC instead of RTD.
During applying ...
3
votes
1answer
88 views
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 ...
0
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1answer
83 views
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 ...
1
vote
1answer
60 views
-20 db/decade Gain Slope requirement for Stability?
I have been learning Analog Filter designing. I started with Loop Compensation in power supply. I came across a document. It ...
0
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1answer
113 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: ...
0
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1answer
60 views
Dynamic Compensator in Control Loop
Sorry if this has been asked previously, but I couldn't find anything here or elsewhere on Google (but maybe I'm searching the wrong terms).
I'm trying to design a Type 2 compensator for a PWM chip I'...
0
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1answer
276 views
AD4610 - Is it possible to eleminate this single overshoot
I am trying to compensate input capacitance of the AD4610. It does not matter if it is actually over- or undershooting - there is always a spike:
I do not have this problem with the OPA4141 for ...
0
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1answer
166 views
design of compensator type 2 for current mode control of boost converter?
I have designed 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 ...
3
votes
1answer
67 views
Compensation for op-amp difference circuit
I have a difference amplifier built with an op-amp (specifically, I'm using the LT6237) with 10dB gain:
simulate this circuit – Schematic created using CircuitLab
As it is, without external ...
1
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1answer
293 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 ...
0
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2answers
73 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}|| ...
10
votes
3answers
2k views
Need for Temperature Compensation of Current Mirror
I am currently learning about current mirror configurations. I have made two of them so far. Both of them worked as desired but, when heated or cooled, the current through the right side (the side ...
0
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0answers
143 views
Overcoming cogging/ripple torque in gimbal motor
So I'm trying to figure out how to spin a camera on a brushless gimbal motor. I am feeding each of the terminals a sinusoidal pwm signal from a via 3 half bridges on the SN754410. Each of the pwm ...
0
votes
1answer
111 views
Type of capacitor for feedback / external compensation
Referring to the capacitor between the output and the inverting pin in an op-amp, in parallel with the feedback resistor --- should I use ceramic (NP0), or thin film?
We're talking bandwidth in the ...
0
votes
2answers
606 views
OP-AMP DC offset compensation
I do not know how to compensate the DC-offset caused by the Input bias current.
simulate this circuit – Schematic created using CircuitLab
How to compensate the input current bias DC offset? ...
5
votes
3answers
2k views
How to compensate gain and offset errors
I have an analog circuit which has an offset error as well as an gain error.
I can measure the analog output of the circuit and I am able to manipulate the gain of the circuit by means of a factor <...
1
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1answer
413 views
Op-Amp's Dominant-Pole Compensation
I'm reading "Op Amps for everyone" (http://web.mit.edu/6.101/www/reference/op_amps_everyone.pdf) and I'm currently studying the chapter about the compensation of op.amps. but I'm missing a passage. At ...
1
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1answer
162 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 ...
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1answer
65 views
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 ...
0
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1answer
829 views
Intuitive to get pole and zero points for lead compensator
The circuit below is a lead compensator. I can easily know exact the pole and zero of the network by deriving the transfer function. However, I am wondering if there is an intuitive method to get the ...
1
vote
1answer
488 views
LM301 comparator and diodes on compensation
I'm trying to understand what's the purpose of the two diodes connected to the compensation pin (8), and what the output of the comparator is supposed to be.
Also, I'd like to remove the 5V supply and ...
1
vote
2answers
420 views
BJT vs OPAMP for RF signal amplification: BJT performs better, why?
I am working on developing RF wave generation from a DDS IC (AD9834-Analog device). The voltage we require as an RF signal is 6 times (3V peak to peak, sinusoidal, DDS output~=0.5V with supply to the ...
6
votes
2answers
1k views
Calculating values for compensation network (boost converter RC+C network)
I'm trying to build a boost converter with current mode PWM control, but I'm stuck at selecting capacitor and resistor values for compensation. I'm using a LT1619 as the controller IC:
simulate this ...
1
vote
1answer
522 views
Input Bias Compensation for a Comparator
I've been working on designing a discrete dual-slope ADC for school, and I've run into a problem. The schematic below shows my proposed input stage, an ideal integrator connected to a comparator. I've ...
-2
votes
1answer
92 views
APD temperature variation
I know that the gain (M factor) of APD (Avalance Photo Diode) changes with temperature at a give reverse bias voltage, therefore, we need to a compensation either using a thermoelectric cooler or a ...
2
votes
2answers
782 views
Finding transfer function of a compensator circuit similar to a type 2 compensator topology
I know how to find transfer functions of op-amp circuits using equations derived from using Kirchhoff's current law (nodal analysis), and normally I don't have any problems solving them. However, I ...
0
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2answers
265 views
Op-Amp Input Bias Compensation for Multiple Feedback Filter
I'm adding an input bias current compensation network to the positive op-amp input of my band-pass multiple-feedback filter.
I'm setting the source impedance for the positive input pin equal to that ...
1
vote
3answers
3k views
Intuitive way to see pole/zero directly from schematic
The image below is the electrical configuration and the transfer function of a type II compensator using OTA.
By looking at the transfer function, we can easily see that the circuit has two poles (...
0
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0answers
308 views
Origin pole in type II compensator using OpAmp
I am reading about Type II Compensator Using Op-Amp from the application report here (page 4).
From the transfer function (4), we can see that there is an origin pole, \$f_{p0}\$. However, the ...
2
votes
2answers
556 views
Compensated Attenuator question
In the explanation, it explains that C2, C3, C4 are for frequency compensating the impedance of C1 which varies according to frequency.
Can someone explain how C2~C4 does it? and why the designer ...
3
votes
3answers
600 views
Approximation of a Non Ideal Differentiator
simulate this circuit – Schematic created using CircuitLab
The above circuit is a differentiator, the op amp is assumed to be a single pole op amp, that is \$ A=\frac{wt}{s}\$
The transfer ...
1
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1answer
286 views
Increase in compensation capacitor for op-amp
I am currently learning to design an op-amp, and understand that using compensation capacitors help to maintain stability of the op-amp.
Currently, my compensation capacitor has a value around 10 pf.
...
3
votes
1answer
474 views
Understanding in-loop compensation for capacitive-loaded OpAmp
I'm trying to understand the in-loop compensation for a simple amplifier loaded with a capacitive load, as seen in this article from Analog:
http://www.analog.com/library/analogdialogue/archives/38-...
1
vote
2answers
72 views
General process for compensating a complex system in the time domain
Say one has a system with feedback wrapping around some "complicated" system (more complicated than the traditional examples given):
simulate this circuit – Schematic created using CircuitLab
\...
3
votes
4answers
386 views
Control theory diagram for feedback circuit with compensation
An op-amp that drives a secondary gain stage might be given like this:
simulate this circuit – Schematic created using CircuitLab
Where it is important to note that FB1 is some impedence (...
1
vote
3answers
1k views
Wheatstone bridge offset
I have a Wheatstone bridge but I don't know the values of the resistances in it.
My excitation voltage is 5 V. But instead of having 2.5 V on each output lines I get one line at 3.3 V and the other ...
