Hi,
I'm designing with BQ34Z100-G1. I have a basic configuration with a 13.8V SLA battery.
Here is the scenario (basically Figure 14 of the datasheet)
1. The negative side of battery is connected to the BQ34Z100-G1 VSS Pin (and also SRP).
2. The SRN side of the sense resistor is Pack -.
3. Our MCU in our system has a LDO powered from Pack + and Pack -, the MCU communicates to the BQ34Z100-G1 via I2C
The VSS pin of BQ34Z100-G1 is not referenced, and can't be referenced to my MCU ground (as this would short the Sense Resistor). I could have a potential 0.125V (max) difference on the 0V state of the I2C pins. I am concerned that I could affect the accuracy of the device during I2C comms.
My question is how to handle the grounds?. Do I need some sort of isolator / translator or is the potential ground indifference not an issue?
Thanks
Stomp!
