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PSoC 4 MCU

AMSH_1344256
New Contributor

24 MHz crystal is used with PSoC-4 to use BLE feature what is the level expected by Crystal at output.

   

what will happen if level at XTAL24I and XTAL24O pin is not equal ?

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1 Solution
ETRO_SSN583
Esteemed Contributor

The RF power levels quite small and non continuous, take a look at this

   

for idea of what power looks like in a BLE application. Note spectrum

   

analyzer should not have IF BW set real low or pulse gets integrated out.

   

 

   

http://www.cypress.com/documentation/application-notes/an92584-designing-low-power-and-estimating-ba...                          AN92584 - Designing for Low Power and Estimating Battery Life for BLE Applications

   

 

   

Regards, Dana.

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ETRO_SSN583
Esteemed Contributor

The osc has an amp between these pins. So your waveform in will not equal

   

waveform out. Plus in order to observe the "real" waveform at these pins

   

requires you use a low C FET probe on the scope, somewhere in the range of

   

1 - 2 pF. A 10 MOhm probe will, if not stop the oscillation, badly load the circuit

   

node you are trying to observe.

   

 

   

Regards, Dana.

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AMSH_1344256
New Contributor

Thanks.

   

In my case i am not able to find output  when downloading "BLE Find me" example hex file in PSOC4 module. However Advertising LED goes up. I used spectrum analyzer near antenna to observe spectrum between ISM band, but nothing is there. What may be the reason?
 i am thinking this may be due to xtal unbalanced output?

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ETRO_SSN583
Esteemed Contributor

The RF power levels quite small and non continuous, take a look at this

   

for idea of what power looks like in a BLE application. Note spectrum

   

analyzer should not have IF BW set real low or pulse gets integrated out.

   

 

   

http://www.cypress.com/documentation/application-notes/an92584-designing-low-power-and-estimating-ba...                          AN92584 - Designing for Low Power and Estimating Battery Life for BLE Applications

   

 

   

Regards, Dana.

View solution in original post

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