RF 25 MHz programmable attenuator amplifier

Frank Eory2

Other Parts Discussed in Thread: LMH6517

Hello,

We have a project with differential output DDS and need to create 2 channels with programmable amplitude. Could somebody recommend some good RF gain/attenuation buffering IC?

The specs I need to target are:

7 dBm to +23 dBm range, 50 Ω impedance

-13 dBm to +7 dBm range, 50 Ω impedance

On the DDS, I can vary the output full scale current with a resistor to get full scale output voltage of 62.5mV to 500mV into a 50 Ω load. You can see that I might be able to make it just with the current adjusting. I have not built the board yet and don't know how good this approach is. Still, any good chips out there?

dBm = 10*LOG10 (V^2 / (R * 0.001)

500mv-> 7.0dBm

62.5mV->-11dBm

over 3 years ago

0 Frank Eory2 over 3 years ago

Prodigy 200 points

I have to add some precision. I can only adjust the power that goes into the two channels simultaneously. I need to adjust the two channels independently, so need to put two programmable gain/attenuation channels.

0 Hasan Babiker31 over 3 years ago in reply to Frank Eory2

TI__Genius 15555 points

Hello Frank,

Can you clarify further on your bandwidth? You only mention a bandwidth of 25MHz in the title, however you say you are looking for an RF amplifier. We have a few RF VGAs that can be found here that might be able fit your requirements: