BQ40Z50: SMBus criteria on the clock high period

John Chou62

Intellectual 2070 points

Part Number: BQ40Z50

hi Team,

customer using bq40z50 with their system.

per system testing, it's found that the SMBus communication Thigh (clock high period) can be 3.905us

this is lower than bq40z50 spec on SMBus Timing requirement min of 4us

while, also checking the system on the shorter time observed, can we also check with the design team's comment on if the 3.905us can be acceptable or any side effects?

Thanks

over 3 years ago

0 Wyatt Keller over 3 years ago

TI__Guru** 105770 points

Hello John,

Can they share a logic analyzer capture of this? Are they using the gauge in broadcast mode? The gauge does not control the clock line if it is not the primary device sending information, this would be done with their host.

Sincerely,

Wyatt Keller

0 John Chou62 over 3 years ago in reply to Wyatt Keller

TI__Intellectual 2070 points

hi Wyatt

the shorter Thigh should not be cause by the gauge.

customer is asking this shorter time whether is acceptable by gauge or any concerns. Thanks

0 Wyatt Keller over 3 years ago in reply to John Chou62

TI__Guru** 105770 points

Hello John,

Usually we have some small buffer on the actual spec, but sometimes this is very small. I would not recommend exceeding the specifications in the datasheet.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z50: SMBus criteria on the clock high period