Re:Linear Circuit Design Handbook (2008)
by analog31 on Friday July 16, 2021 @06:06PM
(#27861773)
My college didn't have an engineering department, but we took electronics as physics majors, using The Art of Electronics. The rules that we learned in class work for a large number of op amp circuits:
1. The inputs draw no current
2. If there is negative feedback present, the output will do whatever is necessary to render the two inputs equal
So you can write the equations for the voltages at the two inputs, include an equation that sets them equal, and solve for the output. To handle circuits like filters, you have to solve using complex numbers. This will be good enough to derive the design formulas in the handbooks.
These days, a third good rule is:
3. Buy an op amp that works as well as needed to obey rules 1 and 2 in your application. Op amps have made huge strides in terms of functionality and ease of design since I was in college 4 decades ago.
1. The inputs draw no current
2. If there is negative feedback present, the output will do whatever is necessary to render the two inputs equal
So you can write the equations for the voltages at the two inputs, include an equation that sets them equal, and solve for the output. To handle circuits like filters, you have to solve using complex numbers. This will be good enough to derive the design formulas in the handbooks.
These days, a third good rule is:
3. Buy an op amp that works as well as needed to obey rules 1 and 2 in your application. Op amps have made huge strides in terms of functionality and ease of design since I was in college 4 decades ago.