Hello guys,
I'm currently a student at the University of Maryland. I would really appreciate it if someone could help me out with the following:
I'm currently doing research with some other students on active filter design (for a vibrometer). We are trying to design an active bandpass filter with a center frequency of 80MHz and a 3dB bandwidth of about 1MHz (Q factor of 80). We tried the multiple feedback and biquad bandpass ones. Now, everything worked completely fine when we simulated the designs on PSPice (Orcad) with the ideal opamp. However, when we replaced the ideal opamp with commercial ones (for example, TI's THS4271), the results we got were very, very far off.
So! My question is.... When I want to look for a suitable opamp, what specifications should I mainly focus on? The GBW should be more than 80MHz, correct? I'm not exactly sure what I should look for if I want the 3dB bandwidth to be 1MHz. Any suggestions you have for me? We've been trying quite a lot of opamps, but none would give us the results we want unless we change the values of our resistors and/or capacitors.
Thanks!
I'm currently a student at the University of Maryland. I would really appreciate it if someone could help me out with the following:
I'm currently doing research with some other students on active filter design (for a vibrometer). We are trying to design an active bandpass filter with a center frequency of 80MHz and a 3dB bandwidth of about 1MHz (Q factor of 80). We tried the multiple feedback and biquad bandpass ones. Now, everything worked completely fine when we simulated the designs on PSPice (Orcad) with the ideal opamp. However, when we replaced the ideal opamp with commercial ones (for example, TI's THS4271), the results we got were very, very far off.
So! My question is.... When I want to look for a suitable opamp, what specifications should I mainly focus on? The GBW should be more than 80MHz, correct? I'm not exactly sure what I should look for if I want the 3dB bandwidth to be 1MHz. Any suggestions you have for me? We've been trying quite a lot of opamps, but none would give us the results we want unless we change the values of our resistors and/or capacitors.
Thanks!
