I supposed it would be a better idea to ask your EE instructors for advise?
Design Amp from the Ground Up
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jscrub
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hello people!
I am new here too just signed up today. Actually this thread was very instrumental in influencing me to sign up.
This is very interesting stuff. I agree about the whole EE degree thing. No time for practical learning. Hands on learning solidifies a lot of the theory in your head.
Anyways yes I too am new to the hobby. I want to do the Cmoy amp to start with. Looks like a good place to start even though its very simple.
I am new here too just signed up today. Actually this thread was very instrumental in influencing me to sign up.
This is very interesting stuff. I agree about the whole EE degree thing. No time for practical learning. Hands on learning solidifies a lot of the theory in your head.
Anyways yes I too am new to the hobby. I want to do the Cmoy amp to start with. Looks like a good place to start even though its very simple.
RLCrisp
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Quote:
You can do pretty well by remembering that all op-amps are integrators (think single pole low pass filter - look at the open loop response). If you want a fun experiment to prove this (you should always prove things with experiments, you have to learn how to eventually), build an inverting opamp and input a triangle wave and a square wave. Look at virtual ground on the inverting terminal. Since the opamp is an integrator you will have the following relationship (don't worry about the constants for now. GBW=Unity Gain Bandwidth, find this on the datasheet).
d(Vout)/dt = Vin/(2*pi*GBW)
Vin=V+ - V-
In your inverting opamp V+ should be ground and V- is the virtual ground, take a look at virtual ground and witness one of the non-ideal opamp behaviors that likely won't be covered in school.
This is also the long way of me saying that you can derive the second-order behavior of the opamp by assuming it behaves as a low pass filter. This is accurate for most work and can be analyzed by hand.
| Originally Posted by FloydCouncil /img/forum/go_quote.gif I can find out a transfer function of a circuit with an op-amp, if I assume the Op-Amp to be ideal and all. But if I don't, I don't understand where to get the real transfer function for the op-amp. |
You can do pretty well by remembering that all op-amps are integrators (think single pole low pass filter - look at the open loop response). If you want a fun experiment to prove this (you should always prove things with experiments, you have to learn how to eventually), build an inverting opamp and input a triangle wave and a square wave. Look at virtual ground on the inverting terminal. Since the opamp is an integrator you will have the following relationship (don't worry about the constants for now. GBW=Unity Gain Bandwidth, find this on the datasheet).
d(Vout)/dt = Vin/(2*pi*GBW)
Vin=V+ - V-
In your inverting opamp V+ should be ground and V- is the virtual ground, take a look at virtual ground and witness one of the non-ideal opamp behaviors that likely won't be covered in school.
This is also the long way of me saying that you can derive the second-order behavior of the opamp by assuming it behaves as a low pass filter. This is accurate for most work and can be analyzed by hand.
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