IMX6SOLOX_I2C backdrive

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

IMX6SOLOX_I2C backdrive

Jump to solution
548 Views
victorafanasiev
Contributor II

In my board, based on the MCIMX6X2AVN08AB microprocessor, I use the real time clock PCF2129T connected to an I2C interface of the microcontroller. The real time clock PCF2129T uses a lithium battery as uninterrupted power source. The lithium battery presents while the system is powered down.  Is it needed to use some bus isolation circuit to prevent back drive from the lithium battery throw lines SDA and SLC of I2C interface to input lines of MCIMX6X2AVN08AB microprocessor or the real time clock PCF2129T ensures an absence the back drive from the lithium battery to lines of an I2C interface?

Labels (1)
0 Kudos
1 Solution
451 Views
art
NXP Employee
NXP Employee

Anyway, since the real-time clock IC and the processor's I2C I/O pads are powered from differend supplies with potentially different voltages, the level shifting circuit must be used on the bus. This level shifting circuit will operate as the bus isolation circuit as well in case of powering down the processor and the rest of the system except of the real-time clock IC.


Have a great day,
Artur

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

View solution in original post

0 Kudos
1 Reply
452 Views
art
NXP Employee
NXP Employee

Anyway, since the real-time clock IC and the processor's I2C I/O pads are powered from differend supplies with potentially different voltages, the level shifting circuit must be used on the bus. This level shifting circuit will operate as the bus isolation circuit as well in case of powering down the processor and the rest of the system except of the real-time clock IC.


Have a great day,
Artur

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos