Cannot addressing for multiple SC16IS750 UART-I2C bridge

[hieunguyenbn]

Hello everyone,

I am using some SC16IS750 via I2C protocol. The SC16IS750 is addressed by using A1 and A0 pins as shown below. However, I can only use 4 cases (VDD-VDD, VDD-VSS, VSS-VDD, VSS-VSS). When one of the SC16IS750 that has A1 or A0 pin connected to SCL/SDA, then it cannot detect that address and also affact other SC16IS750.

So, how to fix this problem ? 

Thank you for you consideration !

[guoweisun]

Hi

Please try that address lines were connected through 10 resistor to the SDA/SCL.

[rklan]

I have a similar issue.

For many years we use the TSSOP version, and all is fine.

A0 is connected directly to the SCL line. It works like a charm, no problems, many thousand units.

But now, I migrated to the HVQFN version and the I2C address is not correct, according the datasheet.

It is working on a different I2C adress than axpected.

The recommendation is the 10 Ohm resistor is not mentioned in the datasheet. Does this work? why?

Can you help me?

[rklan]

I tried this, but it didn't help.

A 100 Ohm resistor however fixes the problem?

Any Idea? What should be used?