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Is it possible to use a Clock Oscillator instead of Quartz crystal oscillator?

SSchm.1
Associate

Hi,

I want to use the ST25R3911B with a MEMS clock source. Is there any possibility to do this?

Regards, Simon

1 ACCEPTED SOLUTION

Accepted Solutions
Travis Palmer
ST Employee

Hello Simon,

It is possible to provide an external clock to the ST25R3911B.

Therefore, XTI can be used as a clock input. In this mode, the test register has to be configured properly:

To disable oscillator and use XTI as clock input, the tana_7 has to be set to “1�? according to chapter “1.2.15 Test access�? of the ST25R3911B Datasheet.

XTI shall not be driven above VDD_D and below GND.

The clock should be 13.56MHz or 27.12MHz and the bit "osc" has to be set accordingly.

In fact, this method is used by us when testing each chip after production.

What is the reason, you want to use an external clock source?

It would be great if you could share your experience.

BR Travis

View solution in original post

2 REPLIES 2
Travis Palmer
ST Employee

Hello Simon,

It is possible to provide an external clock to the ST25R3911B.

Therefore, XTI can be used as a clock input. In this mode, the test register has to be configured properly:

To disable oscillator and use XTI as clock input, the tana_7 has to be set to “1�? according to chapter “1.2.15 Test access�? of the ST25R3911B Datasheet.

XTI shall not be driven above VDD_D and below GND.

The clock should be 13.56MHz or 27.12MHz and the bit "osc" has to be set accordingly.

In fact, this method is used by us when testing each chip after production.

What is the reason, you want to use an external clock source?

It would be great if you could share your experience.

BR Travis

SSchm.1
Associate

Hello Travis,

thank you for your answer.

I build a small device with a 13.56Mhz MEMS Oscillator which supply the Microcontroller and the ST25R3911B with the same clock.

Furthermore manufacturing process damage the all tested Quartz oscillators.

Regards, Simon