Jetson Nano I2C issue

[captainlu1979]

Our project is composed of 18 Jetson Nano modules.
Depending on the backplane I2C Bus of all modules are connected.
One Master module , Multiple Slave modules.

I2C clock: 100 KHz

When I insert 11 daughter boards in the backplane( one master module, ten slave modules),I2C issue happened. The master module received the wrong data from the nine slave modules.

But I insert 10 daughter boards in the backplane( one master module, nine slave modules),I2C communicate normally…

I don’t know the reason. FAE engineers tell that the reason is because of the driver current limitation in I2C bus. And give us the below picture about driver current.

IOL LOW-level output current VOL=0.4V min 3mA(Stand-mode) ; min 3mA(Fast-mode); min 20mA(Fast-mode Plus)

Now I want to know whether we have methods to improve the driver current from 3mA to 6mA.
Does Jetson Nano module support it？

[Trumany]

Hi, do you mean all nano has its pull-up on I2C? It can not be used as that. Only one pull-up on master is available, others should remove the pull-up. We don’t support such request of improve drive current.

[captainlu1979]

In the datasheet ,we find the item

You said you don’t support such request. Why?

[Trumany]

We don’t support your design. You should not add pull-up for all nanos. That will make the pull-up too strong. Please modify that first.

[Trumany]

For correct I2C design of nano, please refer to the design guide. There are trace length, load capacitance and etc. requests as listed in it. That is the guide that customer should follow.

[captainlu1979]

Here is I2C Design Guide.
About the trace lengthe, the Unit (in) is Inch?

[Trumany]

Yes.