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Op Amp Builder - Level 2

How can you create an intermediate SPICE model that includes slew-rate limiting and voltage/current output limits? Here's a JavaScript Calculator that shows you how! Add 2nd/3rd poles to capture the overshoot / ringing of a real op amp. Modify it any way you like, create your own models! Learn how JavaScript can create forms, SPICE models and print it to a text box.

Download a simple page to run/create your own model.
Check out other JavaScript Calculators.

To learn to create these SPICE op amp models:
Quick intro to op amp models
Basic op amp model
Learn various op amp modelling techniques.

SPICE Circuit

spice model

Enter Basic Behaviors

Aol Open-Loop Gain (V/V)
fu Unity-gain Frequency (Hz)
or Gain Bandwidth Product (GBP)
Slew Max Max Vo change per micro second (V/us)
Rin Input R
Rout Output R

Enter 2nd and 3rd Poles

fp2 2nd pole
fp3 3rd pole
Initially set fp2=fp3=10 x fu.
Set to 100 x fu to remove effect.

Enter Voltage and Current Limits

Vo lim How close Vo swings to supply rails
Io lim Max output current

Enter Model Parameters

Subckt Name Name for SPICE subcircuit.
Device Name Name for SPICE subcircuit.
Precision (digits) Precision for moldel values.


C1 = I1max / (slew * 1000000) Capacitor for slew max and fp1.
fp1 = fu / Aol First pole filter to acheive fu.
R1 = 1 / (2 * pi * fp1 * C1) Resistor for fp1 and Aol.
KG1 = Aol / R1 Open-Loop Gain Aol = KG1 * R1.
C2 = 1 / (2 * pi * fp2 * R2) C for fp2.
C3 = 1 / (2 * pi * fp3 * R3) C for fp3.
EVL (See code) Voltage source for Vo Limit.
ECL (See code) Voltage source for Io Limit.

To copy into text file, First Ctrl-A and Ctrl-C inside box above, then Ctrl-V into text file


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