PCA9517DP-118 multi-master mode support

hafiz_haja — Fri, 24 Aug 2018 10:11:34 GMT

Hi All,

I am using the I2C repeater chip PCA9517DP-118 in my design. My application needs to read back voltage data from a voltage sequencer via I2C interface. I am using microprocessor and micro-controller in the module; I need both the microprocessor and micro-controller to read from voltage sequencer in multi-master mode. Microprocessor I2C interface is 2.5V standard, micro-controller I2C interface is 3.3V standard and slave device is also 3.3V standard. Microprocessor I2C level is translated to 3.3V by using the repeater PCA9517 (A side - 2.5V, B side - 3.3V) and then interfaced to slave device. Since micro-controller I2C interface is 3.3V standard it is directly interfaced to slave device. Therefore repeater B side is getting shorted to micro-controller I2C interface. Is there any issue with this method?. In the datasheet there is some static dc offset issue on the B side of repeater. Does this repeater supports multi-master mode on B side of repeater if B side is not tapped to B side of another repeater?. Refer the attached image for proposed architecture.

Regards

Hafiz

Re: PCA9517DP-118 multi-master mode support

AldoG — Mon, 27 Aug 2018 15:02:47 GMT

Hi Hafiz Haja,

There is no problem with your dessign, since the PCA9517 is multi-master capable, the DC off set at B side wont be a problem, just make sure to be at or lower than 0.4V for arbitration or clock stretching to be transmitted to A side.

Regards,

Aldo

topic PCA9517DP-118 multi-master mode support in Other NXP Products

PCA9517DP-118 multi-master mode support

Re: PCA9517DP-118 multi-master mode support