TPS55288: No ACK signal

Hi Sir,

Want to confirm with you, could you configure the TPS55288 internal I2C registers? Such as setting MODE register OE bit to 1 to enable TPS55288 output?

Hi Mr. Liu.

Thank you for reply.

I can't set configu internal registor.

Because this wave form is 1st signal from MCU.

TPS55288 has never reply with ACK signal.

Is 2.2kohm is too small for pull-pu resistor?

Regards.

Hi Sir,

2.2kohm should be OK as the pull-up resistor.

Could you also check Vin pin, VCC pin voltage? Make sure TPS55288 internal circuit is powered.

Hello, Mr Liu.

Thank you for reply.

I had additional evaluation and this issue has already been resolved.

The cause was that the I2C wating time after EN signal was too short.

Mr. Helen ansewerd my question as follows.

But, 100us was not enoug as wating time. I changed this wating time to 1ms, TPS55288 can respond with ACK signal.

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Dear Sir,

It should need some waiting time between EN high to ready to accept the command from I2C master device. 100us should be enough.

Best Regards,
Helen

Hello, Mr Liu.

Sorry for my repeated submission.

Please let me know the suitable wating time for this.

Best Regards.

Hi,

I'll check it. Please wait a while.

Hello, Mr Liu.

Thank you for confirmation.

7~8ms is too long for wating time...

I think it is better to specify in datasheet.

Anyway, I understood this issue. Thank you!

Best Regars.