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risetime in LT Spice

See...

RisetimeMeasurement.pdf

on the Simulation Tools & Macros Page of my website. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson
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RealPulse.pdf

has been added to my Simulation Tools & Macros Page to clear up some questions that are sure to follow. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

I just use an LT Spice pulse generator and add an LC lowpass filter if I want to soften the corners.

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John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

That works, but the drawback is it must be tailored to each application. In my RealPulse component, you just set VL, VH, TD, TR, TF, PW and PER like you would with the "classic" VPULSE.

In addition it actually sets TR and TF as the 10%-90% value, not

0%-100% as in the "classic" VPULSE, and you don't have to subtract off TR/TF from PW as in the "classic" VPULSE.

In other words the "classic" VPULSE sucks >:-}

All my extra custom component creations are to bring Spice simulations as close as possible to real world.

My personal symbol library in PSpice, Mylib.slb, contains 871 personalized symbols, most with customized functionality.

I addition I've modified some other symbol libraries that come with PSpice to meet my own needs... not exactly a Kosher thing to do, if I were still updating, but I'm not... Cadence updates for the PSpice simulator are mostly worthless, AND costly to boot. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

I don't Spice nearly as much as you do, and I want to keep things simple, preferably everything in one .asc file and all plainly visible. That's one reason I like to make things out of parts, and not out of text.

Updates to LT Spice are relatively inexpensive.

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John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

What is shown in the upper left of...

is what appears on the schematic... as you can plainly see on the first page of...

The first link just shows a symbol library shot of my pulse generator.

It's not "out of text".

Keeping "everything in one .asc file" is poor practice... I've had several clients now who can't send me a readable .asc because of the way LTspice sets up symbol calls.

Someday you _may_ become Spice-literate >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Looks like a lot of text to me.

Symbol calls? I haven't had that problem. How is putting a design into multiple files reliable than putting it in one file?

As I said, I don't simulate a lot. What I do simulate works just fine.

Some day you may become FPGA literate. But probably not.

--

John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

Have you looked at the netlist of one of your .asc schematics ??

Bulk. If every one of my schematics contained also each symbol I'd probably need a 100X sized hard-drive.

FPGA programming is not exactly rocket science >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Missed making one comment. If I want to send a PSpice schematic to someone who doesn't have my libraries, there's a tool that will package ONLY the needed files so the client can read them.

That's one of many tools that LTspice lacks. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

If you want to buy a hammer with LED illumination, LCD force readout, lithium battery pack, and wifi, go for it. My old wooden hammer drives nails just fine.

And LT Spice lets me simulate latchup-free blinker circuits.

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John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

Did you ever get your automatic rise time measurement?

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Rick
Reply to
rickman

This isn't bad:

formatting link

I put the cursor on the red plateau, and the voltage is equivalent to risetime in ns. That's faster and more precise than drawing a 10/90 box and reading delta-t.

It would be nice to have a "DVM" that displays a computed value somewhere.

--

John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

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