LowPassLowpass filter 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This is a (inverting) low pass filter. Resistance R1 can be chosen, resistance R2 is defined by the desired amplification k, capacitance C is defined by the desired cutoff frequency.
The example is taken from: U. Tietze and C. Schenk, HalbleiterSchaltungstechnik (German), 11th edition, Springer 1999, Chapter 13.3
Vps 
Value: +15 Type: Voltage (V) Description: Positive supply 

Vns 
Value: 15 Type: Voltage (V) Description: Negative supply 
Vin 
Value: 5 Type: Voltage (V) Description: Amplitude of input voltage 
f 
Value: 10 Type: Frequency (Hz) Description: Frequency of input voltage 
k 
Value: 1 Type: Real Description: Desired amplification 
R1 
Value: 1000 Type: Resistance (Ω) Description: Arbitrary resistance 
R2 
Value: k * R1 Type: Resistance (Ω) Description: Calculated resistance to reach k 
fG 
Value: f / 10 Type: Frequency (Hz) Description: Limiting frequency, as an example coupled to f 
C 
Value: 1 / (2 * pi * fG * R2) Type: Capacitance (F) Description: Calculated capacitance to reach fG 
opAmp 
Type: IdealizedOpAmpLimted 


ground 
Type: Ground 

vIn 
Type: TrapezoidVoltage 

vOut 
Type: VoltageSensor 

r1 
Type: Resistor 

r2 
Type: Resistor 

c 
Type: Capacitor 