Pinging 74HC4046 Users

Started by Jim Thompson in sci.electronics.design10 years ago 96 replies

Finally zeroing in on modeling the 74HC4046 after finding a unpublished AppNote that gave more details on the innards. This is what a fixed...

Finally zeroing in on modeling the 74HC4046 after finding a unpublished AppNote that gave more details on the innards. This is what a fixed frequency looks like, simulation-wise... http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf Comments? Scalings? (This is based on AppNote and Datasheets claiming trip at VDD/2). First release will be VCO only and will be in LTspice forma...


LTSpice: how to simulate a current limiter?

Started by Piotr Wyderski in sci.electronics.design4 years ago 7 replies

Hello, in my sims I often need to simulate a soft-saturable current limiter, usually for AC. The exact construction of such a limiter is not...

Hello, in my sims I often need to simulate a soft-saturable current limiter, usually for AC. The exact construction of such a limiter is not important from the core circuit's perspective. As long as its I(U) is sigmoid or arctan-like, it's fine. What's the simplest way to express such a building block in Spice? Making it out of discretes every time adds considerable obscurity to the sim a...


LTSpice Help

Started by OldGuy in sci.electronics.design9 years ago 23 replies

I am new to Spice as well as LT Spice. I have input most of my circuit after spending much time looking for components. I have not run the...

I am new to Spice as well as LT Spice. I have input most of my circuit after spending much time looking for components. I have not run the circuit yet since I have a hole where a unijunction goes. The circuit additionally uses a triac, scr and transistor. I found the *Programable Unijunction Transistor pkg: TO-226AA .SUBCKT X2N6027 1 2 3 for a "generic" (to me) unijunction. B...


Mixed-signal model of CD4093

Started by bitrex in sci.electronics.design5 years ago 6 replies

Is there a mixed-signal model of the CD4093 NAND Schmitt available that can be used in LTSpice? One that includes power supply connections and...

Is there a mixed-signal model of the CD4093 NAND Schmitt available that can be used in LTSpice? One that includes power supply connections and shows realistic supply currents, etc. Or any of that fashion of CMOS family such as hex inverters that can also be used as negative-feedback analog amplifiers


LTspice Passing Parameters

Started by Ricky C in sci.electronics.design3 years ago

I'm attempting to construct a model for a 4060 device and the oscillator isn't working. I created a model to explore that and got it to work with...

I'm attempting to construct a model for a 4060 device and the oscillator isn't working. I created a model to explore that and got it to work with just two inverters. I had to add parasitics to the outputs before the simulator would run without time step errors. The 4060 model needs to work with a variable Vdd during the simulation, so I've used switches to create a push-pull o


Still waiting for a Ltspice expert answer.

Started by Jamie in sci.electronics.design11 years ago 36 replies

Does the wires assume real life situations to some degree or do we need to add stray inductance, Resistors and caps to act like a board? ...

Does the wires assume real life situations to some degree or do we need to add stray inductance, Resistors and caps to act like a board? I would of thought it would assume an average lay out of one persons worse nightmare and the actual real live circuit would just work better, seeing that this designer would engineer proper protocols on the board. It just seems that I don't se...


Manufacturer' models in separate directories in LTspice.

Started by Fred Abse in sci.electronics.design9 years ago 5 replies

A while ago somebody was inquiring about putting manufacturers' files in dedicated directories. Might have been josephkk, or George Herold, I...

A while ago somebody was inquiring about putting manufacturers' files in dedicated directories. Might have been josephkk, or George Herold, I can't remember. The only way I have found to do it is to put manufacturer directories as subdirectories of /lib/sub. You call them with ".lib " Like ".lib Zetex\ZTX415.sub" -- "For a successful technology, reality mus


Spice Model Problems?

Started by Jim Thompson in sci.electronics.design10 years ago 18 replies

I'm honing my Spice modeling skills and need some suggestions of devices whose manufacturer-provided Spice model doesn't match reality very...

I'm honing my Spice modeling skills and need some suggestions of devices whose manufacturer-provided Spice model doesn't match reality very well, or has serious issues. I'll try my hand at modeling the device and post my results on these newsgroups and on the LTspice list. It would be helpful if, when you make a suggestion, you state where and how it fails to match up with claimed data sh...


Voltage-variable capacitor doesn't work in LTSpice

Started by Joerg in sci.electronics.design8 years ago 92 replies

Gentlemen, Setting up voltage-controlled resistors is easy: R=(V(X)+0.01) or whatever. Works, always did. Doing the same with a capacitor...

Gentlemen, Setting up voltage-controlled resistors is easy: R=(V(X)+0.01) or whatever. Works, always did. Doing the same with a capacitor fails with this error message: Error on line 6 : c1 n002 0 c=(v(x)+0.01) Unable to find definition of model "c" * Unknown parameter "x" WARNING: Less than two connections to node X. This node is used by V4. Fatal Error: Missing capacitance ...


AD834 Spice Model Updated

Started by Jim Thompson in sci.electronics.design8 years ago 1 reply

The Spice Model for the ADI 500MHz Four-Quadrant Multiplier has been updated (AD834_SPICE_Model.zip) on the Device Models & Subcircuits Page of...

The Spice Model for the ADI 500MHz Four-Quadrant Multiplier has been updated (AD834_SPICE_Model.zip) on the Device Models & Subcircuits Page of my Website, adding in the Spice model for RNOISELESS, and also an LTspice schematic symbol. Performance has been verified by Helmut Sennewald. ...Jim Thompson -- | James E.Thompson ...


Any TopSpice Users Here?

Started by Jim Thompson in sci.electronics.design7 years ago 3 replies

Any TopSpice Users Here? I have an OpAmp model out there that runs fine on PSpice, LTspice, HSpice, etc., but balks on TopSpice. The error...

Any TopSpice Users Here? I have an OpAmp model out there that runs fine on PSpice, LTspice, HSpice, etc., but balks on TopSpice. The error report, from the TopSpice output file is: GSw_Sw3 N_22 -VB VALUE {((TANH(9.485/0.1*(V(SHUTDOWN, + GND)-0.5))+1)/2)*(V(N_22, -VB)/1)} 0*ERROR*: mismatched parentheses in above expression check result= -1 0*ERROR*: loading VALUE be...


Ping Win Hill: AoC xChapters 3x.15.4 output monitor

Started by Matt B in sci.electronics.design2 years ago 8 replies

Hi Win, I just picked up a copy of the x-Chapters, and it has already proved itself quite useful! I need to make a negative high-voltage...

Hi Win, I just picked up a copy of the x-Chapters, and it has already proved itself quite useful! I need to make a negative high-voltage pulser, so I'm going to employ a combination of the two- and three-switch reversible kilovolt pulser designs. While I'm at it, I might as well include the output monitor. I decided to simulate the monitor design shown in Figure 3x.114 in LTspice


Hall current sensor simulation

Started by Piotr Wyderski in sci.electronics.design8 years ago 3 replies

Hello all, I am trying to simulate in LTSpice a circuit which contains a Hall effect current sensor (ACS758 for that matter). I don't have...

Hello all, I am trying to simulate in LTSpice a circuit which contains a Hall effect current sensor (ACS758 for that matter). I don't have its model, but the simulation doesn't need to cover all the corner cases, even a simplified model would be enough: There is a 100uOhm resistor R. The voltage drop across it should produce isolated voltage 2.5V+40[mV/A]*I(R). I can handicraft an op...


Ping Charlie Edmondson and Other Early PSpice Team members

Started by Jim Thompson in sci.electronics.design9 years ago 1 reply

From the LTspice List... "analogspiceman" analogspiceman !!PING!! to Jim Thompson, Mike Engelhardt and anyone else who might posses...

From the LTspice List... "analogspiceman" analogspiceman !!PING!! to Jim Thompson, Mike Engelhardt and anyone else who might posses historical insider knowledge regarding PSpice... I am in the process of updating the depth and accuracy of the historical SPICE page over at the LTwiki: http://ltwiki.org/?title=LTspice_Genealogy_-_The_Heritage_of_Simulation_Ubiquity A while ago I ...


LTspice simulation is taking too long to run

Started by MUHAMMAD FAHAD BHUTTA in sci.electronics.design7 years ago 11 replies

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST...

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST ORDER, 3 bit digital output) . The circuit is quite simple. Input (x) -> Difference Amplifier -> Integrator (op-amp) -> Quantizer-> Encoder -> 3-bit Output (Y) -> Feedback DAC to the non-inverting pin of Difference Amplifier (I am using I


Buck-fed push-pull simulation

Started by Piotr Wyderski in sci.electronics.design3 years ago 20 replies

Hi, it is pretty difficult to find something useful about a buck-fed push-pull design, so below is my LTspice simulation of the core...

Hi, it is pretty difficult to find something useful about a buck-fed push-pull design, so below is my LTspice simulation of the core circuitry. I hope it will be useful for somebody. Any improvements are highly welcome. Best regards, Piotr -----------------------8


Non Linear Resistor in LTspice

Started by Ricketty C in sci.electronics.design2 years ago 31 replies

I was looking at a simulation of a current regulator circuit to figure out why the voltage on a current sense resistor is not a nice sine wave-ish...

I was looking at a simulation of a current regulator circuit to figure out why the voltage on a current sense resistor is not a nice sine wave-ish like the applied voltage to the circuit. I expected a bit of distortion around the zero crossing points but otherwise a rectified sine wave. After mucking with the circuit thinking it had to do with transistor currents I realized the


For Paul Schoen and John Fields - autotransformer SPICE models.

Started by Fred Abse in sci.electronics.design9 years ago 6 replies

Following the exchanges on SEB, about autotransformers, and turns ratio, I wrote these models. The subckts should run on any SPICE which...

Following the exchanges on SEB, about autotransformers, and turns ratio, I wrote these models. The subckts should run on any SPICE which supports .param and rser/rpar. The .asy files are for LTspice. The symbols should pick up the subckts without any need for a .lib directive. The first is simpler, requiring primary inductance, turns ratio, and primary resistance. The second examp...


LTspive IV probs

Started by Robert Baer in sci.electronics.design10 years ago 21 replies

I go to http://www.linear.com/designtools/software/ ans download LTspiceIV.exe, then install it. Impossible to update; get error message...

I go to http://www.linear.com/designtools/software/ ans download LTspiceIV.exe, then install it. Impossible to update; get error message that 'Could not read web file: "http://LTspice.linear-tech.com/fieldsync/release.log.gz". That file, if downloaded and applied, crashes with the error "Fatal Error: Trouble converting to curly brace notation: Mismatched single quotes in" [[bin...


Baxandall class-D oscillator squegging and the VBIC model

Started by Bill Sloman in sci.electronics.design11 years ago 31 replies

The Baxandall parallel class-D oscillator "squegs" in real life if you build it with a high value inductance in the current feed and...

The Baxandall parallel class-D oscillator "squegs" in real life if you build it with a high value inductance in the current feed and bipolar switches. An LTSpice circuit using the Gummel-Poon model for the bipolar transistors doesn't show this - it settles down to a stable sinusoidal oscillation within less than a hundred cycles. The obvious effect of using a high value inductor is that the...