I haven't actually run the scope program to see if there's no coupling, but I know that mode doesn't work, anymore, because our old test fails on the new silicon. We have to run the new test that does not use the cross coupled modes. ON screened these parts with the new test before they sent them to us. It's pretty certain there are no problems.
Yes, planning time is here. We have two classes this week and I have one March 10th with 35 teachers (Moreno Valley, CA). After that, we'll start getting our plan together and bring in the community on the whole effort.
Today when the new Rev C chips arrived, Terrell took some P2 Eval Rev B boards from stock to remove the Rev B silicon and replace it with Rev C silicon for testing. He went through four boards to get two good ones. See picture. Anyway, it's not going to be practical to upgrade P2 chips on customer boards from Rev B to Rev C. Terrell said he has to get the whole assembly so hot before the solder reflows that he was worried he was going to turn the whole thing black. In the old days of eutectic Sn/Pb solder, this would have been much more doable.
A side note: considering the difficulties Terrell did experienced, when doing the rework/substitution of the LQFP-100 package (due to the large GND pad) and the tradition of Parallax in backing its products, perhaps your team should consider a two-step soldering-proccess, when assembling the upcoming lots of pcbs.
Despite the increase in costs, perhaps they could use some other interesting lead-free compounds, that can lower the solder melting point during a second step, when only P2 would be soldered in place, while still keeping the final assemblies within specc'd operational limits (e.g. Indalloy #254 and #227).
A side note: considering the difficulties Terrell did experienced, when doing the rework/substitution of the LQFP-100 package (due to the large GND pad) and the tradition of Parallax in backing its products, perhaps your team should consider a two-step soldering-proccess, when assembling the upcoming lots of pcbs.
Despite the increase in costs, perhaps they could use some other interesting lead-free compounds, that can lower the solder melting point during a second step, when only P2 would be soldered in place, while still keeping the final assemblies within specc'd operational limits (e.g. Indalloy #254 and #227).
If we could just get some lower-temp solder paste, we could do the whole board using it. The little 3.3V LDO's are almost impossible to desolder, due to the heat needed on the top plane.
Well, I can certainly vouch for the survivability of going too high temp. I've got an overall darkened Eval Board after reaching maybe 240 degC in an oven. I think I was able to lift any components at will upon removal. Certainly the USB power switch I was targetting offered no resistance. All four GND studs now have their solder excessively pooled at the underside.
There was always going to be some early samples but Ken also has said everything will be about three weeks earlier than first estimated because OnSemi moved the production up.
So what was going to be late April will instead be early April. So, five weeks to go I guess.
I'm waiting for final confirmation from ON Semiconductor. They tend to under-promise and over-deliver.
I believe we'll see the first half of our Revision C chips this month (March) and the second half next month (April). Those who placed orders for the trays of 90 will get shipped as soon as we receive them.
We will also be reducing the price of the current Propeller 2 ES Evaluation Board using Revision B ES P2 chips by 25% to sell them out.
Were the pads reworked to resolve the latchup "problem"? I can't recall. Problem in quotes because latchup only occurs well above spec.
Will Rev. C Eval boards be available? Hoping to have a full collection
We did not put the guard rings around certain n-wells because it would have been a very expensive all-layer change. We're just going to rate the part for 4.0V, absolute max.
Comments
It was nice to be able select neighboring pin for adc input but definitely better if the cross coupling is gone
@"Ken Gracey" planning time!
Yes, planning time is here. We have two classes this week and I have one March 10th with 35 teachers (Moreno Valley, CA). After that, we'll start getting our plan together and bring in the community on the whole effort.
Thanks for the support potatohead.
Ken
Great result, waveform looks cleaner than before.
Another milestone achieved.
A side note: considering the difficulties Terrell did experienced, when doing the rework/substitution of the LQFP-100 package (due to the large GND pad) and the tradition of Parallax in backing its products, perhaps your team should consider a two-step soldering-proccess, when assembling the upcoming lots of pcbs.
Despite the increase in costs, perhaps they could use some other interesting lead-free compounds, that can lower the solder melting point during a second step, when only P2 would be soldered in place, while still keeping the final assemblies within specc'd operational limits (e.g. Indalloy #254 and #227).
If we could just get some lower-temp solder paste, we could do the whole board using it. The little 3.3V LDO's are almost impossible to desolder, due to the heat needed on the top plane.
I'm still using the same board happily every day.
I guess I lost track of the timeline... I was thinking these new chips wouldn't come until April.
Is there a new ETA for general availability of these new, Rev. C, chips? Is that still April?
So what was going to be late April will instead be early April. So, five weeks to go I guess.
Will Rev. C Eval boards be available? Hoping to have a full collection
I believe we'll see the first half of our Revision C chips this month (March) and the second half next month (April). Those who placed orders for the trays of 90 will get shipped as soon as we receive them.
We will also be reducing the price of the current Propeller 2 ES Evaluation Board using Revision B ES P2 chips by 25% to sell them out.
Thanks,
Ken Gracey
We did not put the guard rings around certain n-wells because it would have been a very expensive all-layer change. We're just going to rate the part for 4.0V, absolute max.
To celebrate, Ken has put the P2-ES Eval Rev B boards and the P2-ES Rev B 4-packs on sale:
Propeller 2 ES Eval Board Rev B - $100 (save 33%)
Propeller 2 ES Rev B TQFP 4-pack - $50 (save 50%)
Excellent!
No. That was the only change.