LTspice non-inverting Opamp loop gain.
开云体育You will soon be told this forum is for LTspice-specific questions, not for electronic design.? :{) But I would suggest: ?
? Dave ? From: [email protected] <[email protected]>
On Behalf Of LV via groups.io
Sent: Tuesday, March 25, 2025 1:34 PM To: [email protected] Subject: EXTERNAL: [LTspice] LTspice non-inverting Opamp loop gain. ? Hello, ? There is example for open loop gain simulation for inverting Opamp: C:\Users\...\AppData\Local\LTspice\examples\Educational\LoopGain2.asc ? How to modify probes circuit and connection for Non-inverting Opamp? Especially how I should connect non-inverting input? -- Kind regards, |
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开云体育Dave is a wee bit purist on what is on-topic.
The list has very many members , so we can expect differences of
opinion, and accept them. On 2025-03-25 21:15, BRUCE108 wrote:
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OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion |
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开云体育*Actually*, Dave (me) is not a purist about this side topic! I expected one of the real purists to chime in before this. ? I pointed Victor towards a tutorial on the subject he was asking about. ? Dave From: [email protected] <[email protected]>
On Behalf Of John Woodgate
Sent: Tuesday, March 25, 2025 2:28 PM To: [email protected] Subject: EXTERNAL: Re: [LTspice] LTspice non-inverting Opamp loop gain. ? Dave is a wee bit purist on what is on-topic. The list has very many members , so we can expect differences of opinion, and accept them. On 2025-03-25 21:15, BRUCE108 wrote:
-- ?
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开云体育Hi, Victor. Perhaps I should say 'Salve,
Victor'! I think you need to explain a bit more about your
question. What is it about the Tian method that you need more
information on? In the first place, with no external input, the
opamp doesn't 'know' whether it is inverting or non-inverting;
that is just a matter of how the external signal is fed in. In
the inverting case, it is fed through a resistor, but in the
non-inverting case, that resistor is between the inverting input
and ground, while the external input is applied, either via a resistor or directly, to the non-inverting input of the opamp, which may
have near-infinite internal impedance or a value defined in the
data sheet. On 2025-03-25 21:46, LV via groups.io
wrote:
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OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion |
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For inverting amplifier (like LTspice example) input connected with ground for open loop test.
You can test what happened if you short input with ground for non-inverted amplifier (simple Opamp with 2 resistors circuit).
I think you will be surprised looking at negative AOL :)
So, to check AOL, you need to know whether the amplifier is inverting or non-inverting.
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Kind regards, Victor |
Bell, Dave
John Woodgate
LV
DerekK