TUSB322I: Can I pull up the ID/INT_N pin to 1.8V/3.3V?

Tang Kun

Part Number: TUSB322I
Other Parts Discussed in Thread: TUSB542, TUSB322,

Hi, Team,

I'm trying to use the TUSB322 and TUSB542 in our project. And in the databook (http://www.ti.com/lit/ds/symlink/tusb322i.pdf

over 6 years ago

0 Malik Barton57 over 6 years ago

TI__Guru 64326 points

Hi,

TUSB322I ID/INT_N pin input levels is a function of VDD. Pulling these pin up to 5V or VDD with a 200K resistor is recommend.

0 Tang Kun over 6 years ago in reply to Malik Barton57

Prodigy 50 points

Hi,

Thanks for your response. The VDD recommend setting is 4.5V~5.5V and whole range is -0.3~6V. So Can I pulling the VDD to 3.3V? Will it have some bad influence?

0 Malik Barton57 over 6 years ago in reply to Tang Kun

TI__Guru 64326 points

Hi,

I do not recommend using TUSB322I with VDD as 3.3V functionality cannot be guaranteed.

0 Tang Kun over 6 years ago in reply to Malik Barton57

Prodigy 50 points

Hi,

Thanks. I got it.

0 Tang Kun over 6 years ago in reply to Malik Barton57

Prodigy 50 points

Hi,
I saw the TUSB542 datasheet and in the Figure 16, TUSB322 pin DIR is pulled up to 1.8V and connected to TUSB542. I want to ask that why the DIR pin can be pulled up to 1.8V but ID & INT_N pin must pulled up to 5V or VDD ?
In TUSB 322 datasheet, the DIR/ID/INT pin electrical Characteristic seems to be same.

0 Malik Barton57 over 6 years ago in reply to Tang Kun

TI__Guru 64326 points

Hi,

The DIR, ID, & INT_N pins are open drain outputs. the voltage that the pin is pulled up to does not matter as much as the current following through the open drain output of TUSB322I. If the current following through the input exceeds Iol then the "low" voltage may not be seen on the node. In short, the pull up voltage and pull up resistance can be varied however care needs to be taken to ensure that a "low" voltage is actually achieved. TI does recommend using pulling these pin up to 5V or VDD with a 200K resistor to achieve a proper low voltage.

0 Tang Kun over 6 years ago in reply to Malik Barton57

Prodigy 50 points

Hi,
Thanks very much.

Interface

Interface forum

TUSB322I: Can I pull up the ID/INT_N pin to 1.8V/3.3V?