dear all
i have designed a analog amplifier using op07 . the input voltage is millivolts from..0-100mV and the gain of the circuit is 8.74 . when i apply the input the gain of the circuit increases slowly and takes upto 5 - 10 min to reach the full value. it doesnt shoot up directly to that value.. can anybody please explain me wht might be the problem?
m attaching the daigram along with this...
I have asked around but no one really knows. Most suggest that the resistors value maybe too big, or input too small.
Tell us how you did it when you eventually get it to work.
Normally you shoud have a gain of 8.8 an not 8.74
The behave of your amplifier is anormal
try to change your op amp by a 741 for example
and dont take in acount the output offset voltage when you measure you gain!
dont choose a high frequency (1KHz for example)
Put your scope in AC coupling
good luck!
2 things that will decide the time for op-amp response are
............slew rate
............ capacitance.
If ur slew rate is too low then ur op-amp takes long time to reach full value.
Even if capacitance is too high which is due to Load transistors size and load,opamp will take long time.
So to incease slew rate increase current not by increasing transistor sizes but by increasing overdrives.then capacitance decreases and curr increases.so slew rate increases.