THS6222: THS6222 magnification problem

Hello,

   If you inputting a 100mV you should be getting around 1V with the EVM's configured 10V/V gain. If you are instead getting 1Vpp, I would suggest checking the input and output source impedance since this EVM was designed for connection to 50 Ohm input/output impedance test equipment. 

Thank you,

Sima 

Hello,

On top of Sima's suggestion to confirm the termination of your test equipment (50 ohm differential), were any modifications made to the EVM? Are you using the EVM in both a differential input and output configuration or were changes made for the board to be used as single-ended?

Best,

Hasan Babiker

Hello,

Where you able to figure out the issue with the EVM?

Best,

Hasan Babiker

According to the manual, I changed the demo board to single 12V power supply.

But don't populate transformer T1 on the board, What about R1,R2 and R18?What are their functions? Do improper parameters affect magnification?

Hello,

    Would you be able to attach the file/image again using the insert file option; we are unable to view it. There is no need to change the demo board to operate with single supply; only connecting both V- and GND connector to ground and V+ connector to positive supply voltage. R1 and R2 are used for impedance matching with input source to avoid reflection issues in high frequency applications (as Hasan and I mentioned before it is a 50 ohm differential). R18 is shown as unpopulated in the default evm/demo board, and it could be populated if you wanted to have a single ended output rather than a differential one (similar to R14). Would you also be able to provide us a schematic/image of your setup as well as any scope shots?

Thank you,

Sima

If change to single power supply, INA input, INB grounding, OUTA output, OUTB grounding. .How does R16 connect??

Hello David, 

   I am unable to view the image/file. Follow this post to correctly insert a file or image: https://e2e.ti.com/support/site-support/f/1024/t/761613. From my understanding of your last reply, are you using single ended input and output? R16 connects the 50 Ohm differential (R1 + R2) to ground. Are you the same person as the individual whom originally posted the question?

Thank you,

Sima 

Hello David,

   Are there any updates with this issue?

Thank you,

Sima