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Why is there no dual gate fets in LTspice?

There are many kinds of them for instance from NXP.

Reply to
LM
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Dunno. You might want to join the Yahoo LTspice group, which has a large collection of models in the files section:

(Search for xdgnmos.asy )

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

(Also search the Table of Contents for NXP BF998).

-- Jeff Liebermann snipped-for-privacy@cruzio.com

150 Felker St #D
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Santa Cruz CA 95060
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Skype: JeffLiebermann AE6KS 831-336-2558
Reply to
Jeff Liebermann

And seriously in need of a workable indexing system. ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson

[snip]

Learn to make your own symbols. ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson

I think they have a dual-gate FET symbol, just no models.

--
Tim Wescott 
Control system and signal processing consulting 
www.wescottdesign.com
Reply to
Tim Wescott

I need to get LTspice symbol and library maneuvers into my skill-set. In PSpice I have it down to totally effortless ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| 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

The program must be worth the money. Most software is never effortless no matter how much you master it.

--

Reply in group, but if emailing add one more 
zero, and remove the last word.
Reply to
Tom Del Rosso

I have the "original crispy" MicroSim flavor of schematic capture :-)

So easy to use that OrCAD, then Cadence, chose to crush it. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| 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

s no

    ...Jim Thompson
   |    mens     |
  |     et      |
 |
      |

True. It cant be totally impossible because there are models at NXP. I quess I have to start with Yahoo.

About old simulators. I had in an old 286 machine some similation program, Microsim perhaps. It ran about as fast as this windows version. LT spice should be about a thousand times faster that it.

What can do I do with a BF998.prm? (other than perhaps delete)

Reply to
LM

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

It does seem vague, just a few lines of Help on the subject. But it's straight forward with a little practice.

Cheers

Reply to
Martin Riddle

Don't be vague, just tell me how ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| 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

"Jim Thompson" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com...

Hello Jim,

Open the symbol editor. Place 4 pins. Right-click on each pin to edit the netlist order to the order in the .subckt-line. Draw some nice graphic around it. Write BFXXX into attribute "Value". Edit -> attributes Save.

Place this symbol in the schematic. Change BFXXX to BF998 Include the model file with a SPICE-directive .lib name_of_file

Wire the complete circuit. RUN the simulation.

I have used BFXXX in the symbol, because I had in mind to use it for BF996, BF999, BF???. If I had used BF998 in the symbol editor, I wouldn't have to change it later in the schematic of course. It's also possible to make a symbol only for the BF998. Last but not least you can already specify the model file in the symbol too.

Best regards, Helmut

Reply to
Helmut Sennewald

s no

    ...Jim Thompson
   |    mens     |
  |     et      |
 |
      |

MicroSim was so good I even sprang for the $100+ manual to go with the 'student' version.

As you may know, paying for ANY software rankles me to no end. But PSpice was so good, I both rewarded MicroSim by buying the book and enabled me to create models.

Reply to
Robert Macy

I've been doing PSpice so far back that I ran it under DOS, drew schematics on paper, numbered the nodes, the entered the netlist with some klutzy text editor. My oldest son wrote me a version controller, so that every new netlist and DAT file could be tracked. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| 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

What do you want to use a dual-gate for?

NEC used to have some dual-gate gaasfets, which were cool. They are apparently gone now, along with a ton of other gaas discretes.

--

John Larkin Highland Technology Inc

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jlarkin at highlandtechnology dot com

Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

Reply to
John Larkin

I still have 20 or so Motorola MRF966 dual-gate GaAs FETs in the drawer. They made really beautiful isolation amps--70 dB isolation in one stage, at 100 MHz. RIP.

A pHEMT cascoded with a SiGe:C bipolar is even better, but a lot less convenient.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

t.

s no

    ...Jim Thompson
   |    mens     |
  |     et      |
 |
      |

I still have AND USE my DOS version. Why? because it has the ability to plot BH Curves directly

BHCURVE - GENERATES A BH CURVE FOR A CORE

  • model uses MKS and CGS units of cm and cm^2 for input
  • plot converts to Gauss and Oersteds for output
  • to plot, set Y = B(K1) and X = H(K1) .TRAN 1 6 0 1000uS .OPTIONS ITL5=0 I1 0 1 SIN(0 .1 1 1) I2 0 1 SIN(0 .2 1 2) I3 0 1 SIN(0 .8 1 3) R1 1 0 1 L1 1 0 200 K1 L1 .9999 KBREAK .model KBREAK CORE(AREA=3.27156 PATH=12.90399 GAP=0
+K=100 MS=97772.47 A=500 C=0.2) .PROBE .END

wish LTspice did something like that.

drew it on paper?! memory slipping? just left to right like playing chess in your mind.

Reply to
Robert Macy

Some of the small-signal triode PHEMTs have insanely low Cd-g. It's barely worth cascoding them on that basis.

TI got into gaas and then bailed. Freescale (ex Moto) still makes a few PHEMTs, mostly medium-power (Idss roughly an amp) parts.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

[snip]

I think LTspice can do the same thing. Just think your way thru parameterization. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| 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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