urgent help to calculate the gain of OP AMP

Status
Not open for further replies.
W

wael_wael

Full Member level 4
Joined
Dec 3, 2005
Messages
221
Helped
5
Reputation
10
Reaction score
2
Trophy points
1,298
Activity points
2,760
calculate the open loop gain op amp

hi everybody,

i have to calculate the open loop gain of OP AMP, so if i need 70db as gain and the input is equal to 1 volt, how much the output by volt ?
thanx alot and i want to till u that i know the result but i need to make sure
best regards
 

calculate the voltage from gain

Simply calculate the voltage gain which is 10^(70/20)=3162.27766 V/V then multiply it by the input value which is 1 volt ,you'll get the required output value which is 3162.27766 volts .Note that you'll get this output only if you perform AC simulation as the simulator will solve the linearized model .If you try that at the transient simulation, your amplifier transistors would go into triode and you won't get the expected output .If you want to perform transient analysis, you should make your input voltage exteremely small ,say 1uV .
 

    W

    wael_wael

    Points: 2
    Helpful Answer Positive Rating
calculate gain in op-amp

thanx alot, but what do u mean by extreamly small input. i have tried 10 uv and i got same result, could u explain what do u mean
best regards
 

if you give an extremely large input , your common mode will be disturbed and your bias will be altered.So the input should be as small as possible. Tell us what is the configuration of the opamp you are trying to use, i mean two stage , folded cascode, telescopic etc. The gain for each of these are different. You can also refer to johns and martin for the same.


amarnath
 

    W

    wael_wael

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…