https://www.eenewseurope.com/en/raspberry-pi-spins-its-rp2350-adds-5v-support/ was my point of departure, doubtless a recycled press release.
I shall agree that something is non-coformant, and based on your observations, that the documentation is probably already on that list with probability 1. Martin -----Original Message----- From: Paul Koning [mailto:[email protected]] Sent: 30 July 2025 18:47 To: Martin Bishop <[email protected]> Cc: [email protected] Subject: Re: [cctalk] RP2350 5V Input Tollerant Pins > On Jul 30, 2025, at 1:35 PM, Martin Bishop > <[email protected]> wrote: > > Your caveat that the data sheet requires careful study is completely correct. > Also, the 5V tollerance applies to the A4 revision, date codes / top marks > will also require scrutiny. I would suspect that A4 2050's are not yet "on > the streets". It doesn't say that in the revision history chapter. Instead, it doesn't say at all, which makes people wonder if this is a documentation fix for something that always was there, a now documented capability because of better chip qualification, or if it really is a revision dependent feature that isn't correctly documented as such? paul > > FWIW my low tech TTL --> LVTTL input interface design is a 3v0 Zenner clamp > > Martin > > -----Original Message----- > From: Paul Koning via cctalk [mailto:[email protected]] > Sent: 30 July 2025 16:46 > To: [email protected] > Cc: Paul Koning <[email protected]> > Subject: [cctalk] Re: RP2350 5V Input Tollerant Pins > > There's a small detail that's in the document: some of the GPIO pins double > as analog inputs (for the ADC). Those, unlike the other GPIO (digital only) > pins, are not 5 volt tolerant. Four of the GPIO pins brought out to the edge > of the Raspberry Pico board are those analog/digital combo pins, so for any 5 > volt work you'd have to avoid directly connecting 5 volt devices. > > paul > >> On Jul 30, 2025, at 12:30 PM, Paul Koning via cctalk <[email protected]> >> wrote: >> >> That's interesting. I have been using the RP2350 for a while now but I >> missed that detail. >> >> For what I do, I've found that just a voltage divider works fine for 3 volt >> tolerant inputs with 5 volt drive. And 5 volt TTL seems to be happy with >> the 3 volt logic high that the Pico chips produce. So while voltage >> shifters are well known I haven't found the need for them. >> >> Still this is handy to know. >> >> The RP2350 is quite an amazing chip for very little money. A dollar or two >> more than the RP2040, which itself is already highly capable. By the way, >> there is a very nice FORTH system for these called Zeptoforth; I've been >> doing a bunch of work with that. >> >> paul >> >>> On Jul 30, 2025, at 10:04 AM, Martin Bishop via cctalk >>> <[email protected]> wrote: >>> >>> https://www.raspberrypi.com/products/rp2350/ >>> >>> From postings, I know that folks use the RP2350 for interfacing; the trade >>> press has been shipping news of RP's rev A4 datasheet in volume. >>> >>> The datasheet should tell all. However, the 5V tollerance of the "IO" pins >>> is significant for its simplification of TTL interfacing; the maximum >>> supply and output voltage remains 3v3. See section 14.8.2 (p 1335) et seq >>> - NB the FT indication. >>> >>> Martin >>> >> >
