All Questions
33
questions
3
votes
3
answers
329
views
What does Gain mean when LTSpice plots Gain vs Frequency in AC analysis?
I am trying to simulate the frequency response of a trans-impedance amplifier in LTspice, with a current source input, as shown below:
My question is when doing ac analysis, the gain that LTspice ...
- 505
0
votes
1
answer
64
views
LTspice Bode plot filter analysis
I am designing a π-type LC filter with a frequency cutoff of approximately 1khz. Simulating the filter in LTspice gives the following Bode plot. It starts dropping off at ~100hz before dropping ...
- 614
2
votes
1
answer
108
views
Stability issue: Compensation changes using Bode plot in LTspice
I am encountering issues with a LT8390 design, particularly in higher load current conditions, which leads me to suspect a stability problem. The design parameters are as follows: vin 18-36 (28v ...
- 532
1
vote
3
answers
123
views
Inverting opamp amplifier: frequency response not compatible with LTspice simulation
I have a simple inverting opamp amplifier and I want to study the frequency response of the circuit and finally calculate the frequency band (or cutoff frequency). Unfortunately the model created in ...
- 25
1
vote
0
answers
62
views
Unable to find Gvd of a buck converter using LTspice
I'm trying to simulate a closed-loop buck converter in LTspice. I'm using ideal components. I started by finding the Gvd of the buck converter (duty to output transfer function). I used the .ac ...
1
vote
1
answer
69
views
Discrepancy Between Bode Plot Predictions and FFT Output for Higher-Order Low Pass Filters on a 10 kHz Square Wave
I have conducted an experiment where a 10 kHz square wave is input through low pass filters of 1st, 2nd, 3rd, and 4th orders. After passing the square wave through these filters, I observed the FFT (...
- 283
0
votes
0
answers
49
views
Why is the current source type/waveform influencing the ac analysis in ltspice?
As I understood the ltspice .ac analysis, it would linearize the circuit and solve it with an AC stimulus in the source marked with "AC 1" ( which then ...
- 6,588
0
votes
1
answer
290
views
LTspice Bode plot is incorrect or inconsistent (op-amp circuit)
I'm testing the open loop transfer function of an op-amp circuit by following this schematic:
This is my LTspice schematic (keep in mind the actual op-amp circuit itself has been thoroughly checked, ...
- 1
0
votes
0
answers
95
views
Negative loop gain of LDO
I am trying to design an LDO with the following specification: Vout = 1.5V; Vin = 1.7V - 2V; Iload = 75uA to 1200uA. However, while I am simulating its loop gain, its gain is coming negative. Even ...
2
votes
1
answer
141
views
Why does the Bode plot in LTspice disagree with my command calculation?
I am trying to use LTspice to plot Bode plot for frequency response. I used command to get the gain at the 1kHz first. In the error log it turns out that it is 47.3dB.
When I used small signal AC to ...
- 21
0
votes
0
answers
136
views
Frequency response of a cascade opamp circuit using LTSpice
I'm trying to simulate this circuit which consists of multiple stages of op amps, but I couldn't figure out the operating bandwidth of the circuit. Using AC analysis, the Bode plot is a weird shape ...
1
vote
0
answers
72
views
Is it okay/valid to have a Bode plot that has linear magnitude scale?
I have almost always seen that the magnitude axis of a Bode plot is in dB but today I was shocked when I saw in LTspice that Linear option was also available for Bode representation.
I am very ...
- 11
0
votes
2
answers
307
views
LTSpice: represent group delay when x axis changes
I am trying to plot the group delay of the following circuit. Usually it is enough to change the y axis from phase to group delay. However because I changed the x axis to represent a normalized ...
- 1,431
0
votes
0
answers
748
views
Visually determine pole from Bode plot
Currently I'm taking a basic electronics course and this was a part of homework. The Bode plot represents the frequency response of an amplifier and from this plot we had to determine the dominant ...
- 31
0
votes
2
answers
2k
views
Recreate "Voltage gain vs Frequency" graph of Op-Amp in LT Spice
I am trying to recreate the "Voltage gain vs Frequency" graph of the LT1037 Op-Amp in LT Spice. According to the datasheet page 6 the graph looks like this: -
Trying to recreate this in LT ...
- 4,145