THS3217: EVM cnanot output 5Vpp @ 500MHz

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

Are you using THS3217EVM?

THS3217EVM Evaluation board | TI.com

Yes, I use THS 3217EVM board, I use M8190A generate differntial amplitude 400mVpp 500MHz signal to J1 & J2, usd MSOS804A 50 ohm DC couple to watch waveform at J7. The amplitude only 1.2Vpp, Increase M8190A output level, PA  output don't increase.

Do look at the BUF802 meanwhile , this should certainly give you 2Vpp @ 500Mhz. However do note BUF802 is in a gain of 1V/V.

Alec or myself will also look into why the THS3217 did not perform as per datasheet.

Can you send schematic for the set up as well.

I select internal path and start with 400mV diff input level, Then contunue increase input level, PA Output max output maintain at 1.25V 。

Sorry for the delay here i was on travel last week. Quick question for you when you measure 1.2Vpp are you actually measuring that at the scope? Right now you have a 50ohm + 50ohm termination to give you the 100ohms, but you are going to divide your signal in half. So are you measuring 1.2Vpp or 0.6Vpp at the scope input? 

measured signal at scope input is 1.2Vpp, It meanings 2.4Vpp at the chip out.

is that the performance you are looking for or are you looking for 2.5vpp at the scope input?

Yes, I am loking for at list 2Vpp at the scope input @ 500MHz

We are working on this support for you now.  We have had team members out of office and traveling.

Can you confirm the PD_SW control switch is set to GND for the OPS stage to be turned on?

I also need your confirmation the PATHSEL switch is properly connected for internal routing between D2S stage and OPS stage.  This would result in PATHSEL switch also being connected to GND.

If either switch is connected to +VCC, you would either have a lower output amplitude result (your reported concern) or an OPS stage waiting for external input.

I will  work to validate 5Vpp in lab at 500MHz as you requested.

PD_SW control switch is set to GND for the OPS stage to be turned on and PATHSEL switch also being connected to GND