Questions tagged [parameters]
18 questions
3
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How do I find or calculate BJT parameters for LTspice?
A typical entry line in LTspice's Standard.bjt file contains, e.g.,
.model 2N4126 PNP(Is=1.41f Xti=3 Eg=1.11 Vaf=18.7 Bf=203.7 Ne=1.5 Ise=0 Ikf=80m Xtb=1.5 Br=4.924 Nc=2 Isc=0 Ikr=0 Rc=2.5 Cjc=9.728p Mjc=.5776 Vjc=.75 Fc=.5 Cje=8.063p Mje=.3677…
Carlos Gouveia
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4 answers
LTspice: tables for parameterized passive components... why not?
What I'd really like is to be able to parameterize an impedance like a resistor against frequency with a table and interpolation in AC mode, as in Rf=table(freq,1meg,10,10meg,50)
I remember seeing that freq could sometimes be referenced so I used…
steven suddarth
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1
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0 answers
Can the secondary voltage of this old transformer be derived?
Images are of an unknown "4808" PCB-mounted transformer. It has an open 240 VAC primary.
Data: EI48 core, around 12-15VA. The center-tapped secondary is 15Ω-CT-15Ω and 1.6H-CT-1.6H according to an LCR meter. The primary terminates as tri-filar but…
rdtsc
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LTspice - move the cursor to a particular run in the plot
After running a stepped parameter simulation, the cursor can be moved between different runs using the up and down arrows. This is impractical for a large number of runs. Is there a way to jump to e.g. run 152 without plodding through the runs one…
Hyp
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2 answers
What is the physical significance of beta and alpha in BJT?
I have read in the book that beta is the ratio of collector current to the base current in common emitter configuration and alpha is the ratio of collector current to emitter current to common base configuration.
Also, I know that alpha and beta are…
Pooja Agarwal
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How to simulate a short on LTspice
I'm trying to simulate two scenarios in LTspice. One is when things are ok. The second is when a short happens.
As you can imagine I'm a beginner with LTspice. At first I was just putting a resistor at the output of my circuit to simulate my load.…
Neeko
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What is the (typical) value of SPICE parameter ISS for a (vertical) npn transistor?
SPICE gives a default value for the (collector) substrate leakage saturation current ISS. The default is ISS=0 but I would like to know the real value for an integrated vertical npn transistor. The transistor is an older high-voltage device used in…
Mark
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Magic number in TI white paper "Estimating MOSFET Parameters from the Data Sheet"
I'm reading through a white paper titled Estimating MOSFET Parameters from the Data Sheet (PDF), published by Texas Instruments in 2002, and in section "A3. Gate threshold and Miller plateau voltages", the equation at the top of page 2-43 contains a…
Jim Fischer
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1 answer
Hybrid parameters vs. frequency
The question I need to solve is: how do the h parameters (hybrid) vary as a function of frequency?
In particular, I need to estimate the Y parameters (admitance parameters) for a 2N3904 transistor, but I only have the h parameters, as a function of…
Martin Petrei
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I don't understand this statement regarding measurement of impedance parameter of a transistor
I was reading about hybrid parameters from the text book 'Engineering circuit analysis by Hayt-8th edition'. I read a paragraph saying :-
" The difficulty in measuring quantities such as the open-circuit impedance
parameters arises when a parameter…
Lelouch Yagami
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0 answers
Setting parameters in a Daly BMS using an ESP32
I am trying to set the SET parameters in a Daly BMS by programming an ESP32.
Below is the sample code. I am not able to set the parameters or receive any response.
#include
HardwareSerial SerialPort(2);
void setup() {
//…
0
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0 answers
How can I plot "Vdsat" VS "Vgs" in Cadence Virtuoso?
How can I plot "Vdsat" VS "Vgs" in Cadence Virtuoso? I can place a voltage supply at the Vgs (gate-source voltage), then I give to its value a variable.
After that, I can define that variable in the "ADE L". My problem is that I don't know how can I…
mohammad rezza
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1 answer
How can I find tsmc65N (or 65nm feature size) NMOS parameters definition in Cadence Virtuoso?
How can I find tsmc65N (or 65nm feature size) NMOS parameters definition in Cadence Virtuoso? They are all abbreviated and there is not any guide there.
For example, I want to know the value of "process transconductance parameter" or "kn". in…
mohammad rezza
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0
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1 answer
Why can S21 be simply calculated as 2Vout/Vgen?
For one of the four S-parameters - the S21 - why is that S21 can be translated as 2Vout/Vgen?
Is there a simple explanation for it?
kintaro
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0
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1 answer
LTspice parameter sweep and sampling
Setup
I am trying to run a parameter sweep in LTspice in order to generate STDP curves for a memristor.
I'm doing this by sweeping a time-delta parameter dT between -50 and +50 ms, in order to run 100 transient analyses with the "post-synaptic"…
Thomas Tiotto
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