Any suggestions for >1GHz differential inputs to single ended output amplifier?
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Hello Jeff,
Could you use an FDA either the LMH3401 or LMH5401 followed by an RF balun? Is the system requirement to be DC-coupled?
Currently, we don't offer > 1GHz BW differential to single-ended amplifier but using an RF balun at the output of an FDA could be a solution if DC performance is not required. You would have to compensate then for the insertion loss of the balun in the PA which would be close to 2.5dB, which might be acceptable. Also, it might be good to know what system performance like distortion numbers you are targeting for the differential to single-ended amplifier?
Best Regards,
Rohit
It can be ac coupled. The bandwidth is from 10K to 1G Hz.. I also read it is okay to ground one end of differential amplifier, except losing some benefits of being differential. Is it correct? Jeff
Hello Jeff,
I have done tests with both outputs balanced (same equivalent load) and with the unused output completely floating (still has feedback resistor connected). There was no difference in the performance.
We do not recommend to leave an unused output completely floating, though, so using 200 or 400 Ohms to ground would be a good idea. There is no need to match them exactly.
This recommendation is for single ended outputs only. When using the amplifier in differential configuration it is very important to balance the two outputs.
Regards,
Loren