This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-sdr@lists.osmocom.org/.
Sylvain Munaut 246tnt at gmail.comHi > I again took a buffer (voltage follower) formed of a generic R2R-IO, > unity gain-stable CMOS opamp (MIC7300, TLV9001...). Those supply (or > sink) 40 mA and more. But the max. output current depends on the output > voltage, so, if we want to continue with that approach, I'd likely add a > BJT current helper stage behind the opamp (BJT collector on 5V). We have > almost no dynamic demands on that opamp, so disregarding any phase > errors we introduce by driving large capacitive and resistive loads, it > would work w/o a BJT, but let's see... Heh, I just prototyped something last weekend for another project with controlled VIO using a mcp6001 and a N-mos pass transistor. ( It sure doesn't have the lower drop-out configuration but I think it's more stable that way ). > So I don't see an external ref voltage input on that PCB... maybe your > use case would explain your needs here! ;) I don't see the need for a external vref input. VDDANA is fine. Cheers, Sylvain