Zane83
New Member
hi.. i've some problem in op-amp circuit and wish to have some help here.
when i shorted inverting and non-inverting of the opamp (tl084/tl082 - supplied with +-5V) to ground, the output should be 0V but came out around 5V. as i know this is because of the offset and there're some way to eliminate the offset but i'm not very sure of it.
i tried applying some voltage (hard time adjusting using variable resistor) in series at either input but could not get result of 0V. but when i apply some voltage at the output and trim it, i could get the output of 0V (i'd tried). is this the correct way to eliminate offset voltage or is/are there any other more practical way to do so? i'm confused as from what i read, it supposed to be applying some voltage in series with the input instead of output.
secondly, i tried eliminating the offset (apply voltage in series at output), i manage to amplify the input to my desired gain last week (in breadboard). somehow, i made the same connection (exactly the same) again this week (in PCB board) but the output seems to be increasing (even though i did not increase the voltage in series with output anymore).
is there any reason for the increasing voltage? i'm still figuring out how come i could not get the same output (maybe connection?!)
anyway, ideal op-amp without offset ever exist?
thanks..
when i shorted inverting and non-inverting of the opamp (tl084/tl082 - supplied with +-5V) to ground, the output should be 0V but came out around 5V. as i know this is because of the offset and there're some way to eliminate the offset but i'm not very sure of it.
i tried applying some voltage (hard time adjusting using variable resistor) in series at either input but could not get result of 0V. but when i apply some voltage at the output and trim it, i could get the output of 0V (i'd tried). is this the correct way to eliminate offset voltage or is/are there any other more practical way to do so? i'm confused as from what i read, it supposed to be applying some voltage in series with the input instead of output.
secondly, i tried eliminating the offset (apply voltage in series at output), i manage to amplify the input to my desired gain last week (in breadboard). somehow, i made the same connection (exactly the same) again this week (in PCB board) but the output seems to be increasing (even though i did not increase the voltage in series with output anymore).
is there any reason for the increasing voltage? i'm still figuring out how come i could not get the same output (maybe connection?!)
anyway, ideal op-amp without offset ever exist?
thanks..