i have just received hw revision 1.2 of digi+ pro
i find some interesting changes to 1.1 and some posts by hifiberry here i think is may not longer right for REV1.2 , please clarify a bit
1) there is a termintation resisitor with a termintation capacitor on clock signal trace (RC style termination). in previous revision there were no any.
the benefit of resistor is clear and easy understood in case everything is impedance matched and overall clock signal voltage is still enough. but capacitor? AC termination like this for less overshoot? but it x7r type right? with high dissipation absorption and piezo... the question is, does resistor itself provide full impedance matching, so i can try without this cap (c6)?
2) you provided info that there is no any regulation on board on digi+ PRO. but on REV1.2 there is a U2 that looks like LDO and it connected to P3 +5V with and input capacitor. is this an LDO? is it an ADP150 like on other boards or different one? if i leave it there and add another +3.3V this will not look good because R3 doesn't seem to disconnect U2 from +5V anymore. or i missed something?