TUSB522P: EN always high

Fred Cheng

Expert 4660 points

Part Number: TUSB522P

Hi team,

If I want TUSB522P never shut down (EN always high)

would you recommend I connect it VCC directly or insert a 4.7k ohm?

my customer prefer simple way if 4.7k is not needed

over 2 years ago

0 David (ASIC) Liu over 2 years ago

TI__Guru*** 139965 points

Hi,

I would recommend pull EN_RXD to VCC through a 4.7k resistor.

Thanks

David

0 Fred Cheng over 2 years ago in reply to David (ASIC) Liu

TI__Expert 4660 points

Hi David,

what would happen if it directly connect to VCC ?

since this might increase chance we design in if we don't need extra rework

0 David (ASIC) Liu over 2 years ago in reply to Fred Cheng

TI__Guru*** 139965 points

Hi,

You can tie the EN_RXD directly to VCC, but I would recommend going through the resistor as a current limiting resistor.

Thanks

David

0 Fred Cheng over 2 years ago in reply to David (ASIC) Liu

TI__Expert 4660 points

Hi David,

My opinion is 4.7k is merely nothing compare to the default 600k ohm in the IC,

I don't think this difference would affect a lot.

What's your feedback on this?

0 David (ASIC) Liu over 2 years ago in reply to Fred Cheng

TI__Guru*** 139965 points

Hi,

The 600k is an internal pull-down resistor.

If you look at the EN_RXD pin definition, install a pullup resistor (recommend 4.7 KΩ) for normal operation. The 4.7k limits the current flow and prevents any potential damage to the TUSB522P. If they decide to connect the EN_RXD pin directly to VCC, then it deviates from our recommendation.

Thanks

David

0 Fred Cheng over 2 years ago in reply to David (ASIC) Liu

TI__Expert 4660 points

Hi David,

I recommend they use 4.7k on the premise of they are willing to add one more resister footprint.

since this is 2sd co-lay case.

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TUSB522P: EN always high