Questions tagged [compensation]
For questions about designing electronics to account for undesirable characteristics or behaviors, such as frequency compensation in a feedback control system to avoid instability and/or improve gain and phase margin, reduce overshoot and ringing, improve bandwidth, etc. Consider using in conjunction with associated tags such as "feedback", "stability", "frequency-response", "nyquist-plot", "bode-plot", "operational-amplifier", etc., if appropriate.
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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? ...
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14-Volt 6-Amp Power Supply Stability
Design Requirements:
The purpose is a linear DC power supply for 12-volt aircraft, marine, and amateur radio equipment
power source 20 volts @ +/-10%. (output 85W = 6A*14.2V)
Rser on V1 = 0.4 or ...
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LTspice-RIAA-simulation not working out
I'm trying to simulate a RIAA-phonograph-preamp since I want to build a phono-preamp. I've built everything according to the data provided by LT for the LT1115. But my simulation seems to not be ...
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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 ...
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Integral Compensator Realization from Transfer Function
I am trying to design a compensator based on the transfer function below
Gc(s)=(1.017E6s+4.969E9)/(s^2+4.884E5s)
The transfer function has a constant that is offsetting circuit gain, followed by a low ...
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Tricking feedback of a buck converter
I need to trick the buck converter feedback. The converter that I am going to use is TPS40192DRCT.
Instead of the regular resistor divider, I want to feed there voltage proportional to current ...
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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 ...
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Why this overshoot in transient?
I am designing a forward converter whose output can be variable from 4V to 30V, 0-5A. This is going to be a pre-regulator for a linear converter. This is the schematic:
I am using UC3844 controller ...
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Using UC3844 and TL431 to compensate a forward converter
I am designing a forward converter capable of providing 5A at 30V at the output. For the compensation part, I am thinking to use UC3844 in combination with TL431 to achieve peak current mode control.
...
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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 ...
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What is the better way to stabilize this discrete op-amp and why?
I have the following simple op-amp circuit, which is meant to drive a MOSFET (M1) gate and work as a voltage regulator. It is discrete for a mix of reasons (necessary bandwidth, using existing BOM ...
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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 ...
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Problem stabilizing this PMOS LDO
I am considering a discrete LDO for a supply rail that needs ~\$m\Omega\$ impedance at 10 kHz.
While the following circuit does what I need (according to Spice), it becomes unstable if C2 is smaller ...
- 11k
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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 ...
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What is the term Flc in LM27402?
Hi while going through LM27402 IC, inorder to find compensate components of cc1,cc2 and so on, there is term called Flc, can anyone explain what it is?
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IGBT Temperature Drift: How to Achive Stability?
I remember the BJT transistor circuits are designed to compensate for the fact that the parameters of the transistor change with the temperature. I could not find similar ready-to-use solutions for ...
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Parallel plate capacitor level sensor
Hey all.
in a typical design of a capacitive sensor for level measurements, compensation capacitors are added as a reference. I struggle to understand why we need a reference capacitance to measure ...
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Temperature compensation equation?
I'm looking for the correct temperature compensation equation to use on our project.
We are measuring the output of a detector who's signal is very sensitive to temperature drift. Any external ...
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Trouble with meeting design specifications of a second order system using Matlab
I am trying to solve the following question.
Consider the transfer function $$G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ is in the forward path of a unity feedback control loop. Assume that it is ...
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How to find the compensating gain required for the 2nd order control system to have 5% overshoot
I have a unity feedback control system with $$G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ in the forward path. Now Imagine, I added a static gain K in the forwards path to make the %overshoot 5%. How can I ...
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Why is this buffered rail splitter oscillating and how can I compensate it?
Inspired by the question Op amp Power supply splitter with totem pole I played with the buffered rail splitter in LTspice. I placed a current sink as load on the output to simulate the current ...
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Underlying reasoning behind lead and lag nomenclature of compensation
If \$0<z, \;p\$, the Laplace transform transfer function \$\frac{s+z}{s+p}\$ constitute two distinct types of compensators.
If we look at this schematic, \$0<z<p\$ (lead compensation) implies ...
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Why are complex valued zero and pole not used in lead or lag compensation design?
Consider the compensation transfer function \$\frac{s+z}{s+p}\$ so that the inequalities \$0<z<p\$ and \$0<p<z\$ correspond to lead and lag compensation respectively. It can be seen that ...
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Do lead and lag filters have the behavior of high and low pass filters even if the zero and pole used are complex?
Consider the compensation transfer function \$\frac{s+z}{s+p}\$ so that the inequalities \$0<z<p\$ and \$0<p<z\$ correspond to lead and lag compensation respectively.
At very low ...
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Ratio of zero-pole in a lead compensator
I have a transfer function of a lead compensator designed for double integrator in the form
$$G(s)=\frac{2025}{s^2}\frac{s/39+1}{s/139+1}$$
The zero frequency is 39 rad/s and pole is 139 rad/s. I just ...
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How to improve the accuracy of measured ADC voltage in a circuit connected to Vcc
The question is based on the following setup.
As depicted there is an IC to measure the real value of the 3.3V supply voltage accurately. The measured value of the 3.3V source is transferred via SPI ...
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Offset problems with charge amplifier
I have a question about designing a charge amplifier.
I am currently using this simple setup for my application. As input, I can use several commercial piezo-based accelerometers. I need a pretty ...
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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 ...
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Phase Lag Compensator
I have a question on lag compensators in general.
Why do they increase both the rise time and the settling time? Is it due to the introduction of a slow pole?
Much thanks!
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Dual slope ADC circuit
I`m currently building a dual slope ADC with discrete components. As expected, some errors were observed. I have calculated both the gain error and offset error variables.
Now that I know these ...
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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, ...
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Tilt compensation for yaw calculation from magnetometer and accelerometer
I am working on a project where I have to calculate the roll, pitch, and yaw angles using an accelerometer and a magnetometer.
I calculate the pitch and roll angles using the accelerometer and I am ...
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Maths behing implementing temperature compensation on a signal
I have a fluid pressure sensor (blue line) whose measurements are affected by outdoor temperature (yellow line). So there is a 12 hours cyclic component (day/night) in my pressure measurements. How ...
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Why does overshooting occur when probe's adjustable capacitor is under-value
I can't wrap my head around how overshooting (the spike) happens when the 10X probe capacitor trimmer (Cp) is under-tuned (i.e. adjustable capacitor's value is not high enough). There are countless of ...
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butterworth configuration of multi-stage amplifier
When designing a multi-stage operational amplifier, people usually use butterworth polynomial to set closed loop pole location of the op amp in feedback configuration, and then back calculate to open ...
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fast analytical technique identifying poles/zeros using degree of freedom
I encounter some engineers who can quickly spot poles and zeros in the circuit by identifying "degree of freedom". For example, a typical technical discussion goes like : "a miller ...
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Questions about coil voltage and phase shift in the WPT system
I performed simulations of wireless power transfer in matlab simulink. It was powered with DC voltage which was then converted into a rectangular voltage with a frequency of several dozen kHz. The ...
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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 ...
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Compensation of custom high voltage power supply
To test an offline switching PSU I decided to build a custom isolated high voltage variable PSU. The idea was to build a nice, small, low power equivalent of a variac and isolation transformer that is ...
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Microstrip blocking capacitor ground cutout -- large cutout size
I'm attempting to minimize the \$S_{11}\$ of a \$10\,\text{pF}\$ DC blocking capacitor on a microstrip trace for my signal frequency range, which is \$5.3-5.9\,\text{GHz}\$. My microstrip trace width ...
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3 wire load cell and HX711 weight compensation
in my project I use 3 wire load cell (like this (3wire 50kg) but mine are purchased from ebay) and HX711 for weighing.
My wiring is like this (but i use Arduino mini pro 3V3):
Apparently it should ...
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Using frequency-compensated resistive divider as digital level-shifter
We have all seen the "frequency-compensated resistive divider" circuit in, for example, 10X oscilloscope probes:
simulate this circuit – Schematic created using CircuitLab
Has anyone tried ...
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Sensor Error Adjustment
I have been asked to improve the high end accuracy of a pressure sensor (Without modifying hardware). I have collected data from 30 samples and found a trend to the error. My question now is if it is ...
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How to compensate an op-amp at a particular frequency?
I am trying to design an op-amp but because it is going to be used at a max frequency of 10kHz, I only need to make sure the phase margin is good enough at this frequency. Most of the methods for ...
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Frequency compensation and feedback capacitance
I was reading the chapter of Microelectronic Circuits (Sedra Smith) about negative feedback systems, and it shows an example of Miller frequency compensation with the capacitance Cf shown in the ...
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Two stage op-amp design with compensation ideas
I am trying to design an op-amp with a high-pass feedback. The diagram is shown below. The high pass feedback has a corner frequency at 1Hz.
The op-amp itself is two stage as can be seen below.
...
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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 ...
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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,...
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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 ...
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Implementation of Adjustable Current Limiting Circuit
I have a circuit that can deliver 0-10V and 0-100mA to a load, and want to have an adjustable current limit that will limit the current delivered. To do this I have a current shunt that I monitor, and ...
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