Preston's Element 14 BOM Attempt

[Preston]

Just a quick update for those that are following this thread, I have updated a few of the noted issues from page 3 and most of page 2 of this thread. I will complete the rest on the week end. Sorry for the delay

Some things I would like to note is:
I have added a separate section (not entirely complete yet) at the bottom under AAP and MAP for off board sensor units, either one or the other is ordered not both!

For some components a mouser option is offered to the right, element14 on the left. This is because either element14 is way expensive or does not have the product in stock. As Fred stated earlier there is a delivery fee for Mouser no matter how much you order so if you do plan on getting some components from them we have attempted to make it worth your while

Preston.

[Fred]

Funtastic! :-)

[Preston]

Well I think we are just about there peeps, all feed back has been most appreciated!

External connected MAP and AAP now complete, I have updated the page numbers here as they were referring to the wrong analog conditioning circuit, part reference names also corrected to suit.
Layout changed for ease of viewing here also.

MCU resistors changed to 1%, 5% used for non critical circuits; ie LED's

I may add a few additional Mouser alternative components in over the next couple of days.

I have these two mod/updates to make.

Secondary power:

• Jumper should go from opposite sides of Q19 to D3, you state U4, which although true is much less practical.
• C11 can be either left off or populated with another tant same part number as C8, but should NOT be a BFO electro.
• I would reorder to have reg at top, and all left off or jumpered stuff together at bottom.

One addition that is required! The CPU pins for the XOR inputs need pulling down with 100k. That's 4 channels. I think all of the other FETs have it built in, but the ign ones are on the far side of the XOR so need it twice, once on the FET and once on the CPU pin.

They need to be attached from the CPU side of R230-R233 and go to ground. I don't know what the best solution is, but possibly a through hole 1/4 each laying on the surface somewhere?

Can anyone see anything else I've missed, or needs sorting?

Preston.

[Fred]

Yes! I have a big set of posts coming on cpu/clock for the benefit of all hw projects and to become part of the freeems spec. There are a few changes from that that you need to integrate too. Let me know if/when it is holding you up and I'll prioritise it for you.

[Preston]

Secondary power:

• Jumper should go from opposite sides of Q19 to D3, you state U4, which although true is much less practical.

done!

• C11 can be either left off or populated with another tant same part number as C8, but should NOT be a BFO electro.

Populated with the same component as C8 (10uf tant).

• I would reorder to have reg at top, and all left off or jumpered stuff together at bottom.

done!

Fred. I will do the last part in the morning, when can you get me your change requests?

Preston.

[Fred]

I will try to do that today or tonight among other things. No promises, though.

[Preston]

One addition that is required! The CPU pins for the XOR inputs need pulling down with 100k. That's 4 channels. I think all of the other FETs have it built in, but the ign ones are on the far side of the XOR so need it twice, once on the FET and once on the CPU pin.

They need to be attached from the CPU side of R230-R233 and go to ground. I don't know what the best solution is, but possibly a through hole 1/4 each laying on the surface somewhere?

Done! The mod will be documented in spin1-howto soon.

Preston.

[Fred]

Preston, you're a legend! Thanks mate. For everything.

[Fred]

I have cpu and clock stuff sorted, will post tomorrow.

Fred.

[Fred]

OK, CPU/clock time!

Four sections in this post:

• PLL
• Crystal
• Decouple
• Config

PLL

Use these values:

R175 = 3.3k
C93 = 6.8nF
C94 = 680pF

These should all be tight tolerance parts (1% and X7R) to ensure stability at frequency extremes.

Crystal

C96 is totally absent from your spreadsheet :-) Add it, and... :

R176 should not be necessary, but it does not hurt to order it, perhaps include 1M and 10M in the order, just in case.
C96/C97 are probably fine at 22pF, however this needs to be tuned in-circuit. I'd recommend ordering some smaller values and larger values too, just two of each, say 15pF and 33pF as well as the 22pF units. These should all be tight tolerance parts (1% and X7R) to ensure stability at frequency extremes.

Decouple

Freescale require the use of ceramic X7R capacitors of 220nF/0.22uF for some of these parts and >= 100nF/0.1uF for others, so, make them all 220nF/0.2uF for consistency sake. Making them all 100nF/0.1uF is wrong and mixing them just complicates the order unnecessarily and provides reduced performance.

C95,C98,C99,C100,C101,C102 = 220nF/0.22uF

However!!! : Do NOT forget that half of these are connected incorrectly.

Config

R177, R178, R179, R181, R180 = 10k, so yes, change to R180 is fine/good.

Connections look correct.

After this, I want to give it a full check and make sure that nothing is out of place and then it's order time! :-)

Fred.