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Re: Crystal oscillator oscillation startup
I think you are missing the crystal.? Where is the crystal? Is this really a crystal oscillator?? Or is it a relaxation oscillator without a crystal? What determines the oscillator's frequency? Andy
By Andy I · #160150 ·
Re: Crystal oscillator oscillation startup
I think that is unlikely.? It is a schematic drawing issue, not a model one.? MOSFETs are normally used where the N-channel current flow is into the Drain pin, through the channel, and out the
By Andy I · #160149 ·
Re: Crystal oscillator oscillation startup
@Andy See both /g/LTspice/photo/302220/3911539?p=Created%2C%2C%2C20%2C2%2C0%2C0 and /g/LTspice/photo/302220/3911538?p=Created%2C%2C%2C20%2C2%2C0%2C0 Please correct me
By Cheng Fei Phung · #160148 ·
Re: Crystal oscillator oscillation startup
@Tony The upside-down issue is due to how mosfet_018.lib had been defined, please note that both PM and NM from this lib file had been verified previously. See also
By Cheng Fei Phung · #160147 ·
Re: Vin vs. Load - YX logarithmic plot
You can change to a logarithmic axis (in LTspice) even if the waveform has negative values.? It just won't plot over those ranges.? Best to add a limiting function first (in the waveform window).
By Andy I · #160146 ·
Re: Possible g;itch in stepping parameters
Don't worry, it doesn't matter. An expression like VTHRESH & V(B) is evaluated as if it had been written as (aa + bb) & V(B) Best Regards, Mathias
By Mathias Born · #160145 ·
Re: Possible g;itch in stepping parameters
The above illustrates why '{{' instead of '{' could matter, e.g. when the source file also defines " .param VTRESH = aa + bb ". In that case it matters (because of precedence rules) whether VTRESH is
By mhx@... · #160144 ·
Re: Vin vs. Load - YX logarithmic plot
... and I don't read ahead and see the question has already been answered.? DOH!
By rick_church@... · #160143 ·
Re: Vin vs. Load - YX logarithmic plot
The plot window will give you the chance to scale the axes logarithmically.? Be careful that your results don't include negative or zero values, which will prevent you from selecting log scaling.?
By rick_church@... · #160142 ·
Re: Crystal oscillator oscillation startup
Umm, your simulation is a .DC sweep.? .DC sweeps can't oscillate. Where is the crystal?? Nothing stands out as being the crystal.? If it is there, I apologize.? Please help us by pointing it out.
By Andy I · #160141 ·
Re: Crystal oscillator oscillation startup
There are variety of problems that need fixing first, most importantly: all your N channel? devices are upside-down. I don't actually see a crystal in your schematic, but that's secondary. My advice
By Tony Casey · #160140 ·
Re: Crystal oscillator oscillation startup
Oscillators, especially high-Q ones, often need 'help'.? An XTAL oscillator (in real life) gets a jolt from turning on the power, followed by millions of cycles to eventually ramp up. Simulations
By Andy I · #160139 ·
Crystal oscillator oscillation startup
Here is an initial circuit draft of a crystal oscillator : ck_osc.zip ( /g/LTspice/files/Temp/ck_osc.zip ) I have so far checked the circuit operating points according to the circuit
By Cheng Fei Phung · #160138 ·
Re: Possible g;itch in stepping parameters
In versions prior to 24.1, parameter substitutions almost worked like C-macros. This elicited creative use cases like dynamic nodes, stepping models etc. It also caused hard to fix bugs, in particular
By Mathias Born · #160137 ·
Re: Possible g;itch in stepping parameters
Although I am happy to hear that, I would be real careful about making changes like that.? On face value, this seems like it is a great thing.? But things are rarely as simple as they seem. Are you
By Andy I · #160136 ·
Re: Possible g;itch in stepping parameters
Yes, it is. However, curly braces are perfectly fine in any expression and putting them in a .meas is therefore not incorrect. At least not anymore.
By Mathias Born · #160135 ·
Re: .savestate directive no longer works
It's best to report that in Analog Devices's Engineer Zone, the official place to report bugs. Andy
By Andy I · #160134 ·
.savestate directive no longer works
The .savestate directive? was introduced in version 24.1.0. I have existing files that worked with this directive. Now, when I try to run any transient simulation I get this error "argument not
By bwolfe58 · #160133 ·
Re: FFT of expression of voltages ? #FFT
You can always create an auxiliary behavioral voltage/current source with the desired expression and get the FFT of that output.
By BRUCE108 · #160132 ·
Re: Possible g;itch in stepping parameters
Is that*with* the incorrectly inserted curlies? Sent: Thursday, May 01, 2025 1:10 PM To: [email protected] Subject: EXTERNAL: Re: [LTspice] Possible g;itch in stepping parameters What I mean is you
By Bell, Dave · #160131 ·