Quadrature oscialltor. Hi all, As part of the CV measurements (from a previous post) I'm thinking about a 1 MHz lockin. (Maybe a different...

Quadrature oscialltor. Hi all, As part of the CV measurements (from a previous post) I'm thinking about a 1 MHz lockin. (Maybe a different thread to talk about how to do the switching.) I was wondering if I could make a quadrature oscillator from opamps. (I've got some AD825's I thought I'd try.) Anyway spice seems to think it's possbile. Comments or ideas welcome. (Oh I had to add th...

Hi all, simple question how do I add a library to ltspice. Lib from...

Hi all, simple question how do I add a library to ltspice. Lib from here. https://www.classe.cornell.edu/~ib38/teaching/p360/lectures/wk12/l35/11.1/74hc.lib I've watched a few videos, but not working so well. George H.

I'm trying to add the models of a couple of N-FETs I use to LTSpice. I'm getting a simulation-time error that I can't resolve. Any ideas? ...

I'm trying to add the models of a couple of N-FETs I use to LTSpice. I'm getting a simulation-time error that I can't resolve. Any ideas? Thanks. The error: |M1: Only a level 9 B3SOI can have 6 nodes It thinks I have six terminals on my transistor and only SOI models have that many? Looks like only three to me. The circuit: Version 4 SHEET 1 880 680 WIRE 144 -80 16 -80 ...

.model SMCJ33A D(Ron=.4 Roff=8Meg Vfwd=.7 epsilon=100m Vrev=38.65 Vpk=33 revepsilon=4 mfg=Littlefuse type=TVS) That's in the standard library....

.model SMCJ33A D(Ron=.4 Roff=8Meg Vfwd=.7 epsilon=100m Vrev=38.65 Vpk=33 revepsilon=4 mfg=Littlefuse type=TVS) That's in the standard library. It behaves like a symmetric zener. Why? Does "type" do that? There are unipolar TVS diodes, too.

Hi, all--I'm looking for a curve tracer. Ideally it would be USB-powered, and come with software that would make plots and generate data...

Hi, all--I'm looking for a curve tracer. Ideally it would be USB-powered, and come with software that would make plots and generate data files. Nothing too fancy, just I_C and I_B vs V_CE and V_BE, and the equivalent for FETs. A plus would be automatic computation of beta, V_GSth, Early voltage, and even some of the DC SPICE parameters like emitter and base resistance. It would be ...

If I select edit/draw/arc, it usually draws a circle! Or a lopsided arc. Is there a trick for drawing controllable arcs? -- John...

If I select edit/draw/arc, it usually draws a circle! Or a lopsided arc. Is there a trick for drawing controllable arcs? -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation

I wonder why it requires a noiseless input source to be specified. Any why does it only analyze the noise at one node? Given that, why...

I wonder why it requires a noiseless input source to be specified. Any why does it only analyze the noise at one node? Given that, why do I have to probe that one node? -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com

If I set up a BV with equation V=int(TIME) I expect a clean step of one volt every second. That's not what happens. Steps are slopey...

If I set up a BV with equation V=int(TIME) I expect a clean step of one volt every second. That's not what happens. Steps are slopey and strange. I have to declare a max time step of about 100 us to clean it up, which is a nuisance since I'm running for 500 seconds. Actually, I'm not simulating a circuit, just using some BV's to plot some equations. But still.

https://www.linkedin.com/in/mike-engelhardt-a788a822 -- If a man will begin with certainties, he shall end with doubts, but if he will be...

https://www.linkedin.com/in/mike-engelhardt-a788a822 -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board...

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board simulates input power of 12 volts * 9 tera-amps. We're well along on pcb layout of a new delay generator, but I really want more confidence that everything will work first pass. So in parallel we're prototyping the switchers. https://www.dropbox....

The right-click "component attribute editor" for a part has "value" and "spiceline" fields, which are not very well explained. What's...

The right-click "component attribute editor" for a part has "value" and "spiceline" fields, which are not very well explained. What's the difference? The HELP generically refers to "parameters." I understand "value" can be simply "4.7K" or some extra attributes like "vhigh=5 td=2n". What is spiceline? -- John Larkin Highland Technology, Inc picosecond timing precision...

I've never used ltspice / circuit simulators before; though based on seeing posts to the group from various people seems it's something I might...

I've never used ltspice / circuit simulators before; though based on seeing posts to the group from various people seems it's something I might find useful (noting, of course, this is a hobby rather than something I get paid for). Looked it up, and seems ltspice is a windows/mac application, whereas the native equivalent on linux would be ngspice. To avoid starting with one and switching ...

LTspice is a nice program... well, it's ok in many respects and great in others. But it can be a PITA to find models for. I'm looking at a...

LTspice is a nice program... well, it's ok in many respects and great in others. But it can be a PITA to find models for. I'm looking at a number of possible parts to use in a new design but many of them have no spice models. I'm not so worried about finding an accurate LED model. But I'm using a Schottky diode to prevent back feeding of power through a regulator and I need a

I'm still iterating on my high-voltage pulse generator. Rev C looks very good. I've been pushing it up voltage and frequency (like,...

I'm still iterating on my high-voltage pulse generator. Rev C looks very good. I've been pushing it up voltage and frequency (like, 1200 volts and 4 MHz) and seeing what parts fry, and working on them. I have a dpak schottky diode in a sort of snubber place. According to Spice, it shouldn't get too hot, and it's soldered to all sorts of copper pours and thermal vias and stuff. It's an S...

Suppose I have a circuit with 20 nodes, N1 ... N20. I want to plot the node voltages, left to right on the screen. Any ideas? Clumsy...

Suppose I have a circuit with 20 nodes, N1 ... N20. I want to plot the node voltages, left to right on the screen. Any ideas? Clumsy ways: Build an analog mux and clock it with a counter, plot with time as x-axis Push a pulse into a tapped transmission line to sequence a bunch of switches Export a file and do it in a separate program

Anyone know of a spice model for an LT5560 mixer... or at least some solid numbers... the datasheet is sorely lacking :-( ...

Anyone know of a spice model for an LT5560 mixer... or at least some solid numbers... the datasheet is sorely lacking :-( ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San ...

One of my useless things I think I'll throw together. An audio amp. I have transformers, audio output transformers from a tube amp that have a...

One of my useless things I think I'll throw together. An audio amp. I have transformers, audio output transformers from a tube amp that have a certain feature I need for this. This is a mobile audio amplifier. The basic configuration is shown at the end of this post in Spice. The coils, L1 and L2 are actually a center tapped winding. What I want to know is how much power dare

I need some programmable power supply rails, maybe -5 to +40 volts or so. We have some OPA552s in stock, a nice 60 volt power opamp. It's...

I need some programmable power supply rails, maybe -5 to +40 volts or so. We have some OPA552s in stock, a nice 60 volt power opamp. It's a decomp, and it will be driving a big capacitive load, so there is an oscillation hazard. One of my guys got the model from TI and kluged it into LT Spice. The symbol is ugly but it seems to work. We don't know how to make it look like a real opamp. ...

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the...

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the persistant setting in the tools/control panel menu? Good news: the latest update finally includes the LTM8078 switcher! I'm teaching it how to convert +24 into -5 and -2.5. -- John Larkin Highland Technology, Inc Science teache...

https://www.dropbox.com/sh/6scihn40t60qm7k/AADq46F-s7aBowSgcaVrIr_ua?dl=0 I'm still waiting for the Spice model for the 8078. I think I can...

https://www.dropbox.com/sh/6scihn40t60qm7k/AADq46F-s7aBowSgcaVrIr_ua?dl=0 I'm still waiting for the Spice model for the 8078. I think I can make it do positive to dual negative conversion. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com