Hey guys,
since some months i planned to do a USB powered / qfn using respin of branadics OPA659 Active Probe design for my Rigol 5k..:
http://welecw2000a.sourceforge.net/docs/Hardware/Aktiver_Tastkopf_mit_OPA659.pdfYesterday i read the TI newsletter about the new BUF802:
https://www.ti.com/lit/ds/symlink/buf802.pdf?ts=1643347428244&ref_url=https%253A%252F%252Fwww.google.com%252FAnd tought "should i better do a new design with this nice new device (BUF802)"?
One thing i cannot really understand is :
Should i use it in BF mode or the "pseudo CL" BF mode (Fig:8-11) or in real CL mode..? Do i need the CL mode for an active probe for my needs? Do i care about that DC offset or should i simple only use AC coupled mode of my scope? Or can i simple adjust the dc offset with an external pot before i do a measurment?
I want a 350MHz maybe 500MHz active probe to probe RGMII / SDIO Signals.. i think the BW of the scope is enough (for most of my signals) but i have the issue that the passive probes aren't high impedance enough with >100MHz signals which will result in more blurred signal integrity.. thats why i want an DIY active probe..
Which precesion opamp should i use if i want go the CL way? The suggested OPA140A or are there any better Opamp (which are availabel currently.. ;-))