Maximum Prop cyrstal speed
Philldapill
Posts: 1,283
What is the maximum external crystal that the propeller can handle with no errors? I've seen OzStamp's DLP prop using a 6mhz, and at 16xPLL, that's 96MHZ... 18MHZ more than what is normally used. What's the deal?
Comments
You can use much faster crystals, but you can not run the Prop much faster and have success. The 96 Mhz is about the fastest most people will push the Prop.
Is there a reason you want to push one faster than 96 Mhz?
James L
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
James L
Partner/Designer
Lil Brother LLC (SMT Assembly Services)
Steven
The PLL ALWAYS multiply the Xtal frequency by 16, and if that gets over 160MHz...
Stick to 10MHz or less.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Don't visit my new website...
The PLL works well with 12 MHz crystals, but you should constrain yourself to a divided clock (= PLL8X); I in fact prefer this over 6 MHz/PLL16X).
There might be reasons to not use the PLL, then 20 MHz crystals will do fine , also any input from an external oscillator.
You can use crystals up to 100 MHz or so as long as you don't use the PLL.· But, you have to be careful with part selection (as mentioned in earlier threads).
Leon
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
.. but I have not tried very hard
propeller.wikispaces.com/Oscillator
Leon
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle