Other NXP Products中的主题 PCF8563 pull-up resistors dimensioning

PCF8563 pull-up resistors dimensioning

cant — Tue, 26 Apr 2016 17:05:24 GMT

Hi all,

regarding the d.s. of the PCF8563, at pag. 29, tab. 29, are showed some minimum currents.

In order to dimension the pull-up resistors, it is not clear why are not showed the max values instead of the min ones, because it is open drain, so if the try to connect it directly to Vcc, isn't it in short circuit ?

Furthermore, in the UM10301 there are pull-up values, from whom you can deduct the currents values that are lower then in the tab 29.

Please can you clarify this aspect ?

Thanks a lot

Re: PCF8563 pull-up resistors dimensioning

david_diaz — Fri, 03 Jun 2016 20:29:42 GMT

Hello Antonio,

In this case, the maximum current value for the IOL parameters would be maximum input current (Io) at any output mentioned on the Table28. Limiting values. You must place a pull-up resistor.

In order to dimension the pull-up resistors, I recommend that you go to Chapter 7.1 at the following document:

I2C-Bus specification and user manual.

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know. I will be glad to help.

Have a great day.

David Diaz.

PS: If my answer helps to solve your question, please mark it as "Correct". Thank you.

Re: PCF8563 pull-up resistors dimensioning

HPFONE — Thu, 29 Feb 2024 02:31:34 GMT

Is there a recommended value range for the resistance of the pull-up resistor in PCF8563