BQ78350-R1: how to design isolation SMBus interface

user6501051

Intellectual 775 points

Part Number: BQ78350-R1
Other Parts Discussed in Thread: BQ76940, BQ78350, ISO1540, ISO1540-Q1,

Dear TI expert,

i use BQ78350+BQ76940 design one low side driver BMS, i want to design isolation SMbus interface, how to design it?

have a nice day!

over 1 year ago

0 Shirish over 1 year ago

TI__Guru 57697 points

Hello,

You can use isolation ICs to isolate SMBus ends. I2C isolators will work well. This link is relevant https://www.ti.com/isolation/isolated-interfaces/i2c/overview.html

0 user6501051 over 1 year ago in reply to Shirish

Intellectual 775 points

Hello,

i want to use ISO1540-q1, but VCC1 supply voltage range is 3-5.5V, in BQ78350-R1 who provide SMBus power supply? if i need one dc-dc change 2.5V to 5V? 5V provide the iso1540 Vcc1.

0 Shirish over 1 year ago in reply to user6501051

TI__Guru 57697 points

SMbus pullups are normally provided by external circuit. You will need to power the isolator separately for true isolation

+1 user6501051 over 1 year ago in reply to Shirish

Intellectual 775 points

understand, thanks

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BQ78350-R1: how to design isolation SMBus interface