TS3USB221A / about customer's application

K.Yaita

Guru 29720 points

Other Parts Discussed in Thread: TS3USB221A

Hi Team,

My customer would like to use TS3USB221A for following application.

In his application, the power of 3.3V_STD is always on and 3V_MAIN could be powered off..

So, I'd like to ask two questions.

(1)

My customer concerns about the state of D+/D- when 3V_MAIN is off.

Could D+/D- be Hi-Z if VCC is powered off?

Is there any concern about this usage?

(2)

My customer assumes to disconnect SCL_A/SDA_A when signal A is supplied "H"(S="L").

Is it possible 1D+/1D- to be open as schematic above?

I concern if 1D+/1D- need pull up resistor or not.

Best Regards,

Yaita / Japan Disty

0 C. Ryan Land over 11 years ago

Hi Yaita,

What are the values of the SCL and SDA pullup resistors?

-Ryan

0 K.Yaita over 11 years ago in reply to C. Ryan Land

Guru 29720 points

Hi Ryan-san,

Thank you for your reply.

I heard pullup resistors are 4.7kΩ.

Best Regards,

Yaita

0 C. Ryan Land over 11 years ago in reply to K.Yaita

Hi Yaita-san,

1) There is no concern with this usage.

2) No, there does not need to be a pull-up on the unused lines.

Regards,

Ryan

0 K.Yaita over 11 years ago in reply to C. Ryan Land

Guru 29720 points

Ryan-san,

Thank you. I appreciate for your support.

Best Regards,

Yaita

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