Questions tagged [compensation]
The compensation tag has no usage guidance.
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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 ...
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1answer
82 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 ...
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2answers
73 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 ...
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2answers
402 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
66 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 ...
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1answer
38 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 ...
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2answers
136 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 ...
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0answers
29 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 ...
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0answers
71 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 ...
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0answers
70 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 ...
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0answers
62 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
72 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 ...
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1answer
43 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 ...
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1answer
45 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: ...
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1answer
56 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'...
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1answer
153 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 ...
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0answers
35 views
Microcontroller switching converter compensation
So, I found out that the IL300 from Vishay can be used to isolate signals between isolation boundaries and still achieve excellent linearity (an "isolated amplifier").
I have a few questions:
Is ...
0
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1answer
137 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
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1answer
59 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 ...
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1answer
229 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 ...
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2answers
69 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}|| ...
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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 ...
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0answers
123 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 ...
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1answer
84 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 ...
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2answers
502 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? ...
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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 <...
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1answer
343 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 ...
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1answer
157 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
62 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
698 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
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1answer
438 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
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2answers
353 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 ...
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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 ...
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1answer
476 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 ...
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1answer
87 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 ...
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2answers
685 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 ...
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2answers
238 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 ...
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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 (...
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0answers
244 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 ...
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2answers
500 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
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3answers
551 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 ...
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1answer
256 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
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1answer
419 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-...
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2answers
70 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
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4answers
339 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 (...
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3answers
944 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 ...
2
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1answer
197 views
Oscillations in Precision Voltage to Current Converter Design
I am trying to re-design the TI Precision Design - Low Level (5uA) V-to-I Converter. My design goals are:
Increase bandwidth from around 1kHz to 100kHz (ideally 1MHz in the future)
Increase output ...
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1answer
50 views
Stray Input Capacltance Compensatlon with constant-GBP OpAmp
In the book: Design with operational amplifiers and analog integrated circuits, section 8.2, it shows a circuit as below:
And give:
$$f_{z} = \frac{1}{2\pi(R_{1}||R_{2})(C_{n}+C_{f})},\:f_{p}=\frac{...
6
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1answer
710 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 ...
0
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1answer
139 views
Compensating Saturation Voltage of a transistor
simulate this circuit – Schematic created using CircuitLab
I am working on this circuit, which is a voltage controlled oscillator. I am using the transistor as a switch in this circuit. The ...
