BQ30Z554-R1: Why BQ30Z55 SMBC pin (CLK for the SMBus) be clamped at low level?

Andrew Su

Part Number: BQ30Z554-R1
Other Parts Discussed in Thread: BQ30Z55

in what condition will the BQ30Z55-r3 SMBC pin to be clamp to LOW level? it happens when the device be stored with being powered by a battery, the device should have entered into sleep mode, and the issue may be cleared by pulling up the SMBD pin for >2s. the failure rate is a bout 1~2%.

would you please help to share me in what condition the SMBC will be clamped to low level? is there still risk of this failure after fixing it? will there be potential risk for the devices which passed the test at manufactory?

thanks a lot!

over 5 years ago

Wyatt Keller over 5 years ago

TI__Guru** 105770 points

Hello Andrew,

Can you share a scope capture of this occurring? Are you sure the device was in sleep mode after being stored? The bq30z554-r1 should wake up with a SMBus command or connection.

Sincerely,

Wyatt Keller

Andrew Su over 5 years ago in reply to Wyatt Keller

TI__Intellectual 1645 points

dear Keller,

there is no scope capture as the SMBC pin clamped to GND before connecting to the end equipment, so actually no communication. yes, BQ30Z55 should wake up with SMBus command or connection, but the issue just come as it failed with 1~2% rate. so we do want to understand how it happens and if any method to get rid of the risk~

thanks!

Andy Liu (BMS) over 5 years ago in reply to Andrew Su

TI__Guru 52115 points

This issue will be taken care of offline.

Power management

Power management forum

BQ30Z554-R1: Why BQ30Z55 SMBC pin (CLK for the SMBus) be clamped at low level?