Other Parts Discussed in Thread: SN74AXC8T245
I am working on a LA cable/front end design for an interface to an oscilloscope. The scope takes LVDS inputs on 16 channels at up to 200MHz and I want to create a front end. The circuit attached is my basic idea (only 1 channel shown, 4 x Device B would be needed) and I have a few questions:
1. Is the SN74AUC16240 one of the devices that can be used as a voltage level translator using Vpullup of 3.3V
2. What value would you recommend for Rpullup?
3. The 3 places in the table where Vpullup is shown at 3.3V would suggest that, with Vcc at 1.8V, the AUC device would work for 3.3V and 1.8V logic input levels - changing the AUC to Vcc of 1.2V would then allow 1.2V logic levels to work. Have I got this right?
4. Device A is really my device under test but what protection would make sense going into the AUC device? Would a 100 Ohm resistor in series suffice?
If you think I should take a different approach or use a different logic family, please say so.
Thanks in advance for any help / advice you can give.