For the "old" 741 opamp 10-100kHz (gain drops to 1 at 100kHz) will be high frequency operation, for some "contemporary" opamps, where the rolloff of gain starts at, say, 500MHz, one can say 50-500MHz is high frequency operation ..
Hey nguyennam! Dont confuse things! U urself say that 741 can operate up to 1MHtz with unity gain. I repeat unity gain! can u think of how an op amp with unity gain operates? Effective operation of op amp requires high gain, thats why we assume op amps to have infinite gain. As for u saad, 1KHz is considered high frequency for 741. As a simple rule of thumb be sure that the op amp has at least 10 times gain relative the gain of the amplifier (if the device is to function as an amplifier)
Fig.4 shows theoretical frequency v gain response, whereas Fig.5 shows the same relationship for a more practical situation ..
As a simple rule of thumb be sure that the op amp has at least 10 times gain relative the gain of the amplifier (if the device is to function as an amplifier)
One has to be consequent and call thing as they are: 1kHz, according to the attached frequency-spectrum graph falls into ELF/VLF (very low frequency) category ..
However, ..
From a certain point of view 1$ is a lot of money, therefore, if you think of µA741 working at 1kHz, it is "high(er) frequency operation" ..
op-amps have a very low bandwidth...abt 5-10 hz for a good gain...as the frequency increases...the gain drops gradually...until the gain reaches unity.