SN74LVC1GX04DRLR

Esaki

Hello,

I am trying to generate a square wave ate 13.56MHz using the SN74LVC1GX04DRLR oscillator driver.

1) First a calculate the values of the caps. According to the datasheet :

CL = (C1*C2) / (C1+C2) and C1 = C2. My oscillator has CL = 18pF. Therefore, I have C1 = C2 = 36pF.

2) Then, I calculate the value of Rs. Again, according to the datasheet :

Rs = Xc2 = 1/ (13.56MHz * 36pF * 2 * pi) = 326ohm.

3) Finally, I chose for Rf the same value as in the datasheet : 12Momh.

I made a PCB, with ground plane under the oscillator and soldered everything (and double checked).

It seems like the oscillaiton does not start.

Any idea?

thanks,

0 Avi Chami1 over 13 years ago

Hi,

1. Try putting a lower value for Rf, like 2MOhm

2. Maybe this application note can help a bit:

http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=szza043&fileType=pdf

Best regards

Avi

0 Esaki over 13 years ago in reply to Avi Chami1

Thanks, I will read it.

As for Rf it is a typo. I am using a 2.2Mohm as in the datasheet (not 12Mohm).

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