Buffer or no buffer that's the question..

homerJ · Post by **homerJ** » Sun Apr 03, 2011 4:48 pm

hi,

i want to connect two XS1-L1 devices in a chain.
I plan to use a 25MHz oscillator (for 2 x XS1-L1 + LAN8700) with a standard load of 15pF.
Is an extra buffer (like the 74LVC841A in the XMOS XMP-64A schematic) required for the 25Mhz system clock (for this 3 devices) and the JTag clock (2 devices) ??

Greetings
***

Post by **Berni** » Mon Apr 04, 2011 7:25 am

Well it will all work without buffers but generally its a good idea to buffer system clocks to reduce jitter and such (PLL will multiply that jitter in to a even bigger jitter on the cpu clock)

Corin · Post by **Corin** » Mon Apr 04, 2011 10:13 am

We would recommend that you buffer them (e.g. with a NC7NZ34) and then series terminate the outputs.

Cheers,
Corin

homerJ · Post by **homerJ** » Wed Apr 06, 2011 2:37 pm

ok,
thx!

Buffer or no buffer that's the question..

Buffer or no buffer that's the question..

Re: Buffer or no buffer that's the question..

Re: Buffer or no buffer that's the question..

Re: Buffer or no buffer that's the question..