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PSoC™ 4

ToPh_1104671
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Table 49. External Clock Specifications
CMOS input level only.TTL input is not supported

   

I plan to run PRoC BLE at 5V, so what is these cmos level it wants?
As I have a 8MHz TTL clk available.

   

The ExtClk can not be doubled or multiplied? (PRoC does not have PLL ect?)

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ETRO_SSN583
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CMOS Specs from datasheet, attached.

   

 

   

Regards, Dana.

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ETRO_SSN583
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Clocking, no PLL, see attached.

   

 

   

Regards, Dana.

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ToPh_1104671
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Thanks for the prompt response.
I did think it was referring to triggers levels of cmos (70% Vdd), but just wanted to make sure it was not 1.8V core levels.
So no PLL, I guess is OK as I just want to keep same freq domain, could always switch over to IMO or ECO when I need higher speed.

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ETRO_SSN583
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Don't forget to put some series damping R, 10's of ohms, in series with

   

clock source to PSOC pin, layout dependent, to get good signal integrity.

   

 

   

Regards, Dana.

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