BQ24800: Multiple device connecting to SMBus

Kazuki Kuramochi

Part Number: BQ24800
Other Parts Discussed in Thread: BQ4050

Hello Expert,

I have question regarding BQ24800 and BQ4050.
I'd like to connect BQ24800's SMBus port and BQ4050's SMBus port.

Then, BQ24800 will be turned off when AC input is disconnected but BQ4050 is stilled turned on.
As for above situation, I worry about happing communication issue wit BQ4050 from the powered off BQ24800.
Would you tell whether there is any problem with above use case

Best regards,
Kazuki Kuramochi

over 4 years ago

0 Tiger Zhou over 4 years ago

TI__Mastermind 33335 points

Hi, Kazuki,

I don't see any issue. For SMBus, it is pulled-up externally, the host or client needs to actively pull down to establish communication. Without power, BQ24800 won't pull-down the line.

0 Alberto Medrano over 4 years ago in reply to Tiger Zhou

Prodigy 10 points

Hi, BQ24800 datasheet and evaluation board for this device contain SDA and SCL (as I2C), my question, finally BQ24800 is I2C or SMBus device?
Sorry, my English is very poor.
Regards

0 Tiger Zhou over 4 years ago in reply to Alberto Medrano

TI__Mastermind 33335 points

BQ24800 is a SMBus-based device.

Power management

Power management forum

BQ24800: Multiple device connecting to SMBus