Op Amps for Everyone - The Repeater Builder's Technical ...

Block Diagram Math and Manipulations
Transformation Before Transformation After Transformation
Combine Cascade
Blocks
A
K 1 K 2
B
A
K 1 K 2
B
Combine Parallel
Blocks
A
K 1
+
Σ
±
B
A
K 1 ± K 2
B
K 2
Eliminate a
Feedback Loop
A
+
Σ
±
K 1
B
A
K 1
1 ± K 1 K 2
B
K 2
Move Summer
In Front of a Block
A
K
+
Σ
±
C
B
A
+
Σ
±
K
1/K
C
B
Move Summer
Behind a Block
A
B
+
Σ
±
K
C
A
B
K
K
+
Σ
±
C
Move Pickoff In
Front of a Block
A
B
K
B
A
B
K
K
B
Move Pickoff
Behind a Block
A
A
K
B
A
A
K
I/K
B
Figure 5–6. Block Diagram Transforms
Feedback and Stability Theory
5-5