Hi,
10MHz or 1MHz cutoff frequency?
Cutoff frequency x 100 is a good value to start.
It depends what precision in output you need. If you need low THD, low output impedance, good precision in gain, then increase value.
If it is not that problematic, then you can reduce it.
Hey,
For the filter I'm designing, the cutoff frequency is 1MHz, 5MHz and 10MHz. I will come up with a logic to tune the cutoff frequency and that is not a problem. The problem lies in designing the OPAMP for this particular frequency application.
To realize this filter with sallen-Key, I should have an opamp with GBW as 100xFc, which is 1GHz. Is this correct?
Should I design an opamp with very low impedance and with GBW as 1GHz?
Also, to mention, my power specification is 20mW and IIP3 is 20dB.
Please help me with this.
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Why reinvent the wheel? Figure out how it is already done.
Then realize the source impedance must be much lower (<<10%) than the selected impedances for the filter feedback, no matter how high it is.
This one has 3 stages of buffering.
Hey Sunny,
Using three stages of buffering will not affect the stability of the system?