TPD12S016: The difference of Low level between CEC_A/HPD_A and SDA_A/LS_OE

Hirotaka Matsumoto

Part Number: TPD12S016

Hi all

Would you mind if we ask TPD12S016?

Our customer uses TPD12S016 and has the same connection between TPD12S016 and AM57XX like as the attachment file.

20180614_TPD12S016.pdf

We have the question the difference of low level voltage(VIL) between CEC_A/HPD_A and SDA_A/LS_OE.

On the customer's board;
CEC_A / HPD_A : 0.4V
SDA_A / LS_OE : less than 0.1V

On the datasheet P6, the VIL(Max) value of CEC_A and SDA_A is the same as 0.082×VCCA.
However, there is the differece.
Does it mean cause of sink capability at AM57XX?(I2C usually drive 3mA, GPIO pin less than 3mA??)

If you have some advice, could you let us know?

Kind regards,

Hirotaka Matsumoto

over 5 years ago

0 Chuck Branch over 5 years ago

TI__Mastermind 25820 points

Hirotaka,

I do not know why CEC_A and HPD_A would be so much higher VIL on the customer board and am not familiar enough with the AM57XX family to explain the difference between the two results.

The TPD12S016 should present a 10kOhm +/- 30% resistor to the AM57XX for all pins, and it's impact should be consistent across all 4 pins. The difference of 300mV is not expected behavior.

Can you confirm that the PCB resistors R245, R246, R247, and R248 are not inserted on the design?
I suggest you also open up an E2E request with the AM57XX team and copy me on it.

Regards,
Chuck

0 Hirotaka Matsumoto over 5 years ago in reply to Chuck Branch

Guru 27525 points

Chuck san

Thank you so much for your reply.
We assume that it causes of customer's board.
At first, we persuade our customer to check the board whether there is partial resistance or not.

Kind regards,

Hirotaka Matsumoto

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TPD12S016: The difference of Low level between CEC_A/HPD_A and SDA_A/LS_OE