50ohm driver/buffer for measurement

[Ruritania]

driver 50ohm

Hi, all,

Does anyone here have the experience of designing the on-chip 50ohm driver/buffer for cable connection with testing equipment? The requirement on the driver/buffer are: wide bandwidth, high linearity and driving capability.

Thank you in advance,

Ruri

 

[salerno]

designing a driver/buffer

It depends on the specs. I think that for high frequency (=> GHz), the CML approace is the better one. To improve linearity you could use resistance degeneration. This helps also to have a better gain control. If you want to control the amplitude, a control loop should be implemented as well.

For lower frequencies, you should use local feedback on the differential pair to improve linearity behavior.