[time-nuts] Motorola Oncore GPS Interface Board

David Forbes dforbes at dakotacom.net
Mon Nov 27 15:49:55 EST 2006


Jason Rabel wrote:
> A good initial buffer chip for all the TTL signals would be an IDT QS3384
> with 10 inputs/outputs.
>
Jason,

The only problem with that part is that it's not a buffer! It's a 
switch. It has no drive capability at all.

There are useful buffer chips for this task, but their names escape me 
just now. Perhaps the 74FCT245 or equivalent would work.

Driving a full 5V TTL signal into a 50 ohm load is another matter - you 
need a lot of DC power (1/2 watt) to do that. I was just using a Liner 
Tech LT1010 for a similar job - it would get the job done, but folks 
here might complain about the phase noise.



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