AM67: TUSB321 id pin resistor value in AM67 reference design

louis.chang

Intellectual 260 points

Part Number: AM67
Other Parts Discussed in Thread: TUSB321,

Tool/software:

Hi Sirs

We find resistor in TUSB321 id pin in AM67 reference design is 10K pull high.

However, TUSB321 id pin is suggest to 200K pull high in TUSB321 datasheet

Do you know why? Is 10K resistor in id pin still ok?

Thank you

3 months ago

0 Luis Parga 3 months ago

TI__Intellectual 970 points

Hi Louis,

The maximum high-level input current (Iih) for the ID pin, as specified in the electrical characteristics section of the datasheet for TUSB321, is 20uA. Based on this, I believe 200K pull up is what should be used. I am not sure why 10K is being used in the AM67 reference design.

Hi Stanislav,

Do you happen to know why 10K was used for AM67 reference design?

Best regards,

Luis Parga

0 Anastas Yordanov 3 months ago in reply to Luis Parga

TI__Expert 3225 points

Hi Luis,

I see the discrepancy between the AM67x reference design (PROC170 E3B) and the TUSB321 wrt to the pull-up resistor value. I will try to internally discuss with TI HW expert and come with an answer in next 2 days.

Kind Regards,

Anastas Yordanov