PCA85063A with external oscillator?

[theo1]

Can you use a PCA85063A RTC with an external oscillator?

Thanks.

[reyes]

Hi,

The PCA85063A RTC does not include internal oscillator, only PCF2127 and PCF2129 from the NXP portfolio include internal oscillator, so, the PCA85063A RTC circuit requires one external tuning fork quartz as resonator (external oscillator) to work.

What it is integrated in the PCA85063A are the oscillation capacitors and therefore there is no need for external capacitors.

The quartz crystal must be placed close to the RTC circuit, avoiding long lines which may pick up noise.

Regards,

Jose

[theo1]

Thanks Jose.

What I mean is can you use an TCXO with a logic level output instead of a crystal?

[reyes · Accepted solution]

Hi,

Yes, you can use an TCXO instead of a crystal. In this case no crystal will be connected to the OSCI and OSCO pins. Instead, the external oscillator is connected to the OSCI pin while the OSCO pin must be left floating.

Regards,

Jose