DS90UB925Q-Q1: How many time should we wait after PDB to send I2C commands ?

Pial

Expert 7280 points

Part Number: DS90UB925Q-Q1

Dear team,

I currently have one case where after releasing PDB on the 925, the first I2C command sent results in a NACK.

Same thing on the deserializer side: first communication results in a NACK.

Is there any guideline regarding the initialization time of the 925 ?

For the deserializer (924), I understood that we should wait for the LOCK (>>40ms after a valid FPD Link stream is present on the input).

Thanks a lot!

Best regards,

over 5 years ago

0 Aaron Heng over 5 years ago

TI__Mastermind 37510 points

Hi Pial,

Could you please let me know what is the IDx setting to for both 924 and 925?

Aaron

0 Pial over 5 years ago in reply to Aaron Heng

TI__Expert 7280 points

Hi Aaron,

Thank you for your help.

The IDx pin is low on both 924 and 925, so the address of the DS90UB925Q is 0x18 and the address of the DS90UB924 is 0x58.

BTW, can you confirm that after a reset on the deserializer (0x01=1) we also need to wait for the LOCK before sending I2C commandes ? (seems pretty obvious, but I always like to double check everything..)

Best regards,

0 Pial over 5 years ago in reply to Pial

TI__Expert 7280 points

PS: in case it changes anything in the ser/des initialization, please note that both 925 and 924 are configured in LFMODE.

thanks again!

0 Aaron Heng over 5 years ago in reply to Pial

TI__Mastermind 37510 points

Hi PA,

When PDB is approaching from low to high, the PDB wait time before execute the I2C command is >2ms.

Aaron

Interface

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DS90UB925Q-Q1: How many time should we wait after PDB to send I2C commands ?