Engee documentation

Operational Amplifier

The perfect operational amplifier.

blockType: AcausalFoundation.Electrical.Elements.OperationalAmplifier

op amp

Path in the library:

/Physical Modeling/Fundamental/Electrical/Elements/Operational Amplifier

Description

The Op-Amp block models an ideal operational amplifier. The figure shows a schematic of the implementation.

op amp schem

The block implementation is based on the following assumptions:

  • the gain of an ideal operational amplifier A is assumed to be infinite.

  • then for a finite output it must be V1 = 0.

  • the ideal operational amplifier also implies that the current from p to n is zero (i1 = 0).

These assumptions lead to the following equations for the block:

equations
  v1 == p.v — n.v;
  v1 == 0;
  i1 == 0;
end

Ports

+ - non-inverting input
electricity

Electricity port, represents the non-inverting input + of an operational amplifier.

- is the inverting input
electricity

Electrical port, represents the inverting input - of the operational amplifier.

out is the output
electricity

Electrical port, represents the output of the operational amplifier.

Parameters

Initial value of current into output node - initial value of output current
0 (By default)

Initial value of current into output node.

Examples