BQ25703A: BQ25703A I2C timing

Chung SENLIN

Prodigy 80 points

Part Number: BQ25703A
Other Parts Discussed in Thread: LP5562, LP8556, TUSB544,

We have some questions about I2C timing requirements defined in BQ2573A data sheet. (Rev. A, May 2018)

Here are the requirements.

Since these marked items are too long, we can’t fulfill them if I2C bus works over 100KHz.

For example, if I2C clock is 400KHz, its period is 2.5us, how does it pass these requirements?

They are also much larger than other I2C slave devices.

Here are three TI solutions.

LP5562:

LP8556:

TUSB544:

regards,

Mark

over 5 years ago

0 Joel Hernandez II over 5 years ago

TI__Mastermind 25800 points

Hey Chung,

They parameters listed were listed only for the 100kHz test case.

Future revisions to the datasheet to reflect 400kHz will be made.

Regards,

Joel H

0 Chung SENLIN over 5 years ago in reply to Joel Hernandez II

Prodigy 80 points

Hi Joel,

Thanks, may i know when can we get the BQ25703A spec update with i2c 400K timing?

regards,

Mark

0 Jeff Yang76 over 5 years ago in reply to Joel Hernandez II

Intellectual 490 points

Hi Joel,

Could you provide the tW(H), tW(L), tSU(STA), tH(STA) and tSU(STOP) minimum value in 400kHz condition for reference?

Thanks!

Jeff

0 Joel Hernandez II over 5 years ago in reply to Chung SENLIN

TI__Mastermind 25800 points

Hey Mark,

We do not have a timeline for this update currently as we are still gathering other revision we want to make on this device datasheet.

Regards,

Joel H

0 Joel Hernandez II over 5 years ago in reply to Jeff Yang76

TI__Mastermind 25800 points

Hey Jeff,

You can refer to the I2C specification available publicly online for those values related to the 400kHz clock frequency. Our charger will match those values and not violate the I2C protocol.

Regards,

Joel H

0 Jeff Yang76 over 5 years ago in reply to Joel Hernandez II

Intellectual 490 points

Hi Joel,

So could you give us one 400kHz clock frequency chip P/N for reference? ex. L8556?

Thanks!

Jeff

0 Joel Hernandez II over 5 years ago in reply to Jeff Yang76

TI__Mastermind 25800 points

Hey Jeff,

The I2C specification can be found here: https://www.nxp.com/docs/en/user-guide/UM10204.pdf

And there is another good resource here: https://www.i2c-bus.org/specification/

Regards,

Joel H

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BQ25703A: BQ25703A I2C timing