Ah wait, you're right! I overlooked U120. I was actually also confused by C200…C207, which happen to be on VCC3V3 and would in numbers make sense to decouple the two 7404s, U204 and U203. Sorry!
On 11.06.21 15:39, Marcus D. Leech wrote: > On 06/11/2021 09:11 AM, Marcus Müller wrote: >> Hello Jim, >> >> >> hm, that knowledge base article must be wrong: The octoclock internally only >> has a 3.3V >> supply. But before I say something wrong here, let me check back. >> >> >> Best regards, >> >> Marcus > The 1PPS outputs on the Octoclock are bufered by 7404 inverters, which appear > to have a > 5V Vcc. > >> >> >> On 11.06.21 14:17, Jim Palladino wrote: >> >>> Hello, >>> >>> We are planning on using an octoclock with several devices, including an >>> N320. The >>> octoclock outputs a 5V 1pps signal, but I'm confused about the N320 1pps >>> input. >>> >>> According to (https://kb.ettus.com/N320/N321): >>> "PPS - Pulse Per Second Using a PPS signal for timestamp synchronization >>> requires a >>> square wave signal with the following a 5Vpp amplitude." >>> >>> If I look at the schematics for the N320, on page 15, >>> (https://kb.ettus.com/images/f/f4/USRP_N3XX_MB_Schematic.pdf) they show >>> that the input >>> 1pps signal goes through an NC7SV157. Vcc for that is 3.3V in the >>> schematics. >>> >>> According to the datasheet, the absolute maximum rating on the input is >>> 4.3V. >>> "https://www.onsemi.com/pdf/datasheet/nc7sv157-d.pdf"; >>> >>> So, I'm not sure how the N320 can safely accept a 5V input (from the >>> octoclock or other >>> device). >>> >>> Thanks, >>> Jim >>> >>> >>> _______________________________________________ >>> USRP-users mailing list -- usrp-users@lists.ettus.com >>> To unsubscribe send an email to usrp-users-le...@lists.ettus.com >> _______________________________________________ >> USRP-users mailing list -- usrp-users@lists.ettus.com >> To unsubscribe send an email to usrp-users-le...@lists.ettus.com > _______________________________________________ > USRP-users mailing list -- usrp-users@lists.ettus.com > To unsubscribe send an email to usrp-users-le...@lists.ettus.com _______________________________________________ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
