BQ25700A: BQ4050 Fuel gauge and BQ25700A SMBus operation w/o host controller

Prajith Cheerakkoda

Part Number: BQ25700A
Other Parts Discussed in Thread: BQ4050, BQ25710

Hi Team,

I'm searching for the right components for USB Type C/PD power bank design. Based on my preliminary research BQ25700A can meet my charger requirements. I'm wondering if this part can independently work with BQ4050 fuel gauge over SMBus interface w/o MCU/Host controller intervention.

Thanks

Prajith

over 5 years ago

0 Tiger Zhou over 5 years ago

TI__Mastermind 33625 points

The answer is no. Both BQ25700A battery charge controller and BQ4050 fuel gauge need to interface with a host controller/MCU.

0 Prajith Cheerakkoda over 5 years ago in reply to Tiger Zhou

TI__Expert 8680 points

Hi,

But BQ4050 datasheet (7.3.14 communications) says it can work in MASTER mode. May I know why MCU is a must? Is this limitation coming from BQ25700A.

Thanks
Prajith

0 Tiger Zhou over 5 years ago in reply to Prajith Cheerakkoda

TI__Mastermind 33625 points

Hi, Prajith,

BQ25700A needs to talk to a host to set the charge voltage and charge current, etc. I am not familiar with BQ4050. I just haven't seen a solution like you mentioned. FYI. BQ25710 is a new device, which is pin-to-pin and software compatible to BQ25700A.

0 Prajith Cheerakkoda over 5 years ago in reply to Tiger Zhou

TI__Expert 8680 points

Hi,

Please find the attached application note for the solution Im looking for.How to Operate a non-host fuel gauge and … (3).pdf

Power management

Power management forum

BQ25700A: BQ4050 Fuel gauge and BQ25700A SMBus operation w/o host controller