BQ27750: Some times hold I2C bus.

Spider

Part Number: BQ27750

Hello!

I'm trying to work with BQ27750 by i2C bus, but sometimes BQ stop answer ant it can occurs in middle of byte transfer.

First:

Why ACK bit was after so long period? Some times all fine, some times so....
At I2C but alsoe exists BQ24193 - this chip work fine with same master and same i2c code.

Second:

Zoomed in.

And last:BQ hold clock after start and Master can't start send ADDR. Why?

Forexample BQ24193 work fine all times:

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

Hi
The gauge clock stretches during flash updates. Pls see the technical reference manual for additional details.

thanks
Onyx

0 Spider over 6 years ago in reply to Onyx Ahiakwo

Intellectual 350 points

As I right understand, I can read status not offer then once per one second? And if I read when flash nor accessable BQ "doing" clock stretch?

How long it can stretche?

Can I stop "stretch" and break session?

0 Onyx Ahiakwo over 6 years ago in reply to Spider

TI__Guru* 76230 points

No you can't stop the device from clock stretching. Clock stretching can be as long as 150ms during DF updates.
thanks
Onyx

0 Spider over 6 years ago in reply to Onyx Ahiakwo

Intellectual 350 points

At bottom of 80th page of Technical Reference have written that i2c clock stretch can be disabled and switched to NACK mode. But I can't find way how to write to this register. How?