New answers tagged feedback
1
vote
Op Amp Feedback Resistors
Introduction
Both non-inverting and inverting op-amp amplifiers use the same voltage divider as a feedback network; only in the former, it is an ordinary 1-input device while in the latter, it is a 2-...
- 18.2k
6
votes
Op Amp Feedback Resistors
There are a few considerations.
Frequency- at high frequency various capacitances have an effect so you don't generally want to be using MΩ resistors at high frequencies. It could cause poor behavior ...
11
votes
Op Amp Feedback Resistors
To a first-order approximation, it's a matter of how much current the op-amp can provide (sets a lower bound on resistance), how much power you can stand to consume (sets a lower bound) how much error ...
- 36.4k
0
votes
Accepted
Given an active filter or any sort of operational amplifier with finite open loop gain, is feedback factor accounted for in the standard gain formula?
A first-order high-pass transfer function in s-space may be expressed in either one of the following forms:
$$\begin{align*}H_s&=A\cdot\frac{s}{s+\omega_{_0}}\\\\&=A\cdot\frac{\frac{s}{\omega_{...
- 11.8k
0
votes
Accepted
Understanding GBP, closed loop gain and open loop gain
Since you are given an open loop gain, but not a gain-bandwidth product it's likely that you are supposed to assume that the opamp has infinite bandwidth (what else can you do?). By the way, your ...
- 4,361
0
votes
Accepted
Transfer function of an operational amplifier with finite open loop gain - did I do this correctly?
Knowing the expression for Acl(s) - as given in your post - it is best to use this formula with finite open-loop gain Aol - together with the feeedback factor, also given in your text. Please note ...
- 27.4k
1
vote
Accepted
If I have an operational amplifier with a finite open loop gain, can I calculate the transfer function neglecting the open loop gain?
It's a bit of a chicken and egg problem.
First, you calculate the circuit gain \$G\$ by assuming an ideal opamp with infinite open loop gain \$A_{ol}\$, infinite input impedance, etc.
Then, you can ...
- 80.3k
1
vote
If I have an operational amplifier with a finite open loop gain, can I calculate the transfer function neglecting the open loop gain?
Yes, you can assume an ideal opamp which as infinite gain and infinite resistance. In that case V+ is equal to V-.
In the real world opamps have finite open loop gain and bandwidth. If you aren't ...
- 87.1k
1
vote
Accepted
Finding an expression for the transfer function and mid-band gain of a real operational amplifier with a capacitor in its feedback network
The best and fastest way to obtain the transfer function in a clear and ordered form - read low-entropy type of expression - is to resort to the fast analytical circuits techniques or FACTs. You have ...
- 23k
Top 50 recent answers are included