Op Amp Builder - Level 2
Create your own SPICE Macromodels
SPICE Circuit
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.
Calculations
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.
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