Post History
The mistake you made seems quite trivial. LTSpice recognizes your 20M as 20mHz (milihertz). If you want 20MHz, then you need to write "20MEG". That's all. However, when I ran your schm, I got a ba...
#2: Post edited
by
Designalog
·
2025-05-30T12:54:02Z (about 4 hours ago)
The mistake you made is seems quite trivial. LTSpice recognizes your 20M as 20mHz (milihertz). If you want 20MHz, then you need to write "20MEG". That's all.- However, when I ran your schm, I got a bandwidth of about 1MHz, which didn't make sense, as I expected a pole at about 430kHz with a 1st-order roll-off. There seems to be some extraneous zero that cancels this pole and it rolls-off with the op-amps parasitic poles (~-40dB roll-off, so 2nd order).
- That's as much as I found out. You probably have to characterize the op-amps in LTspice and in Analog's website to see who's wrong. But by the looks of it, I'd tend to trust the Analog's website one.
- The mistake you made seems quite trivial. LTSpice recognizes your 20M as 20mHz (milihertz). If you want 20MHz, then you need to write "20MEG". That's all.
- However, when I ran your schm, I got a bandwidth of about 1MHz, which didn't make sense, as I expected a pole at about 430kHz with a 1st-order roll-off. There seems to be some extraneous zero that cancels this pole and it rolls-off with the op-amps parasitic poles (~-40dB roll-off, so 2nd order).
- That's as much as I found out. You probably have to characterize the op-amps in LTspice and in Analog's website to see who's wrong. But by the looks of it, I'd tend to trust the Analog's website one.
#1: Initial revision
by
Designalog
·
2025-05-28T21:40:57Z (2 days ago)
The mistake you made is seems quite trivial. LTSpice recognizes your 20M as 20mHz (milihertz). If you want 20MHz, then you need to write "20MEG". That's all. However, when I ran your schm, I got a bandwidth of about 1MHz, which didn't make sense, as I expected a pole at about 430kHz with a 1st-order roll-off. There seems to be some extraneous zero that cancels this pole and it rolls-off with the op-amps parasitic poles (~-40dB roll-off, so 2nd order). That's as much as I found out. You probably have to characterize the op-amps in LTspice and in Analog's website to see who's wrong. But by the looks of it, I'd tend to trust the Analog's website one.