DAC38RF89: DC Coupled amplifier to drive DAC38RF89

Antony Kahumbu

Part Number: DAC38RF89
Other Parts Discussed in Thread: LMH5401, OPA695, OPA659

Hi Support,

Could you recommend an amplifier(s) for differential to single ended conversion of the RF89's output? I would like to output a 4Vpp DC coupled signal into a 50 ohm load at DC - 1GHz of bandwidth.

Thanks,

Tony

over 3 years ago

0 Rob Reeder over 3 years ago

TI__Mastermind 20130 points

Hi Tony,

I would recommend the LMH5401, see link below. It can be used for DC coupling and provide the BW you need as well as be configured for DIFF to SE on the output of the DAC.

Keep in mind the output swing will be limited to 2.7Vpp with the single-ended output.

https://www.ti.com/lit/ds/symlink/lmh5401.pdf?ts=1595554265124&ref_url=https%253A%252F%252Fwww.google.com%252F

Regards,

Rob

0 Antony Kahumbu over 3 years ago in reply to Rob Reeder

Prodigy 60 points

Hi Rob,

Thanks for your quick response. Since the LMH5401 has differential output, would you recommend I terminate the other output into a 50 ohm resistor? How about pairing the lmh5401 with an OPA695, would that get me to. my target 4Vpp output?

Regards,

Tony

0 David Chaparro over 3 years ago in reply to Antony Kahumbu

TI__Genius 11980 points

Hi Tony,

I have contacted someone who knows a more about our amplifiers and will let you know what they say about pairing those two together or possibly a different part that would be better suited for your application.

Regards,

David

0 David Chaparro over 3 years ago in reply to Antony Kahumbu

TI__Genius 11980 points

Hi Tony,

Pairing the LMH5401 with the OPA659 will work to get you the 4 Vpp output swing that you want. However it was mentioned that the -3 dB BW will be limited to 450MHz because of the OPA659. To terminate the unused output you would use a 100 ohm resistor to the output CM.

Regards,

David Chaparro

RF & microwave

RF & microwave forum

DAC38RF89: DC Coupled amplifier to drive DAC38RF89