Re: BeamRaC=er® ;-) and Reloaded Boards

From: laughton_at_cyg.net
Date: Thu, 02 Jan 2020 13:00:33 -0500
Message-ID: <16c71c925ae1f9a230626363f8bedf71_at_cyg.net>
> "bring your board under microscope, cut the 12th 0,0Xmm wide trace out 
> of 37 running close to each other, then .... "

Hmmm, yeah... I can see how that suggestion might not appeal to all 
users!  :)


> I have to fiddle somewhere in the middle (of the transmission line).

No easy answer, then.

Would it make sense it install a noninverting buffer IC and break the 
signal path into *two* transmission lines?  There are some really tiny, 
single-gate IC's available in 6-pin SMD packages, and the prop delay is 
generally 3 ns or less.


A quick plug re these IC's:  I can't promise they're the solution to the 
issue at hand, but these IC's do offer a *lot* of problem-solving power. 
  Anyone who enjoys hacking hardware should become familiar with them, 
IMO.  For an overview, see my post on anycpu.org  "Tiny, superfast gates 
rival programmable logic"

http://anycpu.org/forum/viewtopic.php?f=16&t=270&p=1803

Jeff


On 2020-01-02 12:27, silverdr_at_wfmh.org.pl wrote:
>> On 2020-01-02, at 17:55, laughton_at_cyg.net wrote:
>> 
>>> maybe someone has a better idea on how to "fix" that clock
>> 
>> My first instinct would be to put a low-value resistor in series with 
>> the signal, with the resistor physically located near the IC pin which 
>> is the source of the signal.  No capacitor, just a resistor...  47 
>> ohms, maybe, but in the range of roughly 22 to 100 ohms.
> 
> Right, this type of "source termination" comes to mind first, as
> easiest and quite effective. The problem is that I can't really fix
> this on the board[*], where the actual source lies so I have to fiddle
> somewhere in the middle (of the transmission line).
> 
> 
> * - theoretically I could probably do this on my unit, but I surely
> can't tell everyone who would be willing to put BeamRacer into
> Reloaded board to "bring your board under microscope, cut the 12th
> 0,0Xmm wide trace out of 37 running close to each other, then .... "
Received on 2020-05-30 00:05:04

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