Hi everyone, I want to amplify the output of AD9850 DDS chip using operational amplifiers. This amplification needs to be adjustable via a potentiometer. This need to be from several millivolts to 10 V peak to peak.
Earlier I built an amplifier for another project but it is not working for more than 100KHz. I have attached that file too.
If someone can please point me in the right direction of how to achieve my goal.
amplifying is done in stages. about 10 db per stage. a 100 milliwatt input amp can produce about a watt out, that 1 watt amp can put out about 10 watts, et cetera. you would not be building AN amp, you would be building a series of amps in a cascade.
go to the public library and find a copy of the ARRL handbook. you will be studying for a while
I guess you will need special opamps that can handle this frequencies. Most opamps will have builtin measures to not amplify these high frequencies (as that would make every amplifier a high frequency wave generator (and transmitter in this case).
If these fast opamps do not exist you can build a transistor based amplifier.... I have build those for 100 MHz....
Edit: they do exist (at least for signal processing) look at site of Mouser or Texas Instruments.
As the output impedance is not stated, we do not know the output power... Maybe OP can shine a light on that!
You can do a 1000x amplification in some opamps
(1 mV peak to peak to 1V peak to peak).
But then you will loose on linearity and might also ask for trouble as even small positive feedbacks will turn your amplifier into a tone generator (especially at these high freqs).
Output required is 50 Ohm, basically this is for a function generator which needs to have coarse and fine adjustment for amplitude.
That is a lot of power for an opamp (if we assume a class A amplifier). If such an opamp exists, it will need proper cooling...
Maybe an opamp combined with 2 transistors would be an option?
Maybe ask a moderator to move this item to general electronics? You can flag it to get their attention...
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