PCF8563 add 1 or 2 external capacitor?

[qpgydlh]

Hi,

I‘m not sure should I add 1 capacitor on OSCI or 2 capacitor on OSCI ,OSCO pin? Is it 8pF too small?

The crystal CL is 12.5pF.And the crystal is nearly close to the PCF8563 pin.

As the Datasheet tips show Cload= [ (Ctrim*Cosco)/(Ctrim+Cosco) ]  should I add 1 external capacitor 22pF on OSCI pin just fine ？ OSCO pin no need external capacitor because OSCO has already have internal capacitor?

thanks!

 

[guoweisun]

No exactly value but around 600mV.

[guoweisun · Accepted solution]

Please refer to below picture mentioned value:

[qpgydlh]

What are the requirements for the driver level of crystal ？

Is it continuous  drive the crystal?or just in start-up?

[guoweisun]

 It is the continuous  drive  internal  of IC.

[qpgydlh]

Another question，What is the operation voltage range in OSCI （Oscillation amplitude）and OSCO pin？not absolute maximum range. 

[guoweisun]

No exactly value but around 600mV.