TPS82130: Enable pin logic

Timothy Tran2

Intellectual 420 points

Part Number: TPS82130

Hi,

If the Enable pin is left open, is the device in enabled or disabled mode or any issue?

Thanks,

Tim

over 7 years ago

0 Chris Glaser over 7 years ago

TI__Guru**** 151290 points

Hi Tim,

It looks like there may have been a graphic that didn't embed correctly in your post.

Section 7.4.1 in the D/S explains the internal pull-down resistor's operation. If the pin is low, and then floated, it will be kept low by the 400k.

0 Timothy Tran2 over 7 years ago in reply to Chris Glaser

Intellectual 420 points

Hi Chris,

As I read D/S section 7.4.1 Enable and Disable (EN) and your explanation, I just wanted to clarify:

How do I disable the device? do I need an external signal to pull down the EN pin?

What happen when the EN pin is left open?

Thanks,

Tim

0 Chris Glaser over 7 years ago in reply to Timothy Tran2

TI__Guru**** 151290 points

Yes, you need to drive the pin high and low. This is also written on page 3 of the D/S.

0 Timothy Tran2 over 7 years ago in reply to Chris Glaser

Intellectual 420 points

hi,
what would happen when the EN pin is left open/floating?
Thanks,
Tim

0 Chris Glaser over 7 years ago in reply to Timothy Tran2

TI__Guru**** 151290 points

Hi Tim,

EN is a digital input, so it can be either high or low. I explained what happens when it is low and then floated in my first post.

If it is high and then floated, it would depend on the leakage current and other noise sources in the system. These could pull it low, at which point the pull-down resistor would activate.

If EN will be floated, I recommend an external pullup/down to keep it in a known state.

0 Timothy Tran2 over 7 years ago in reply to Chris Glaser

Intellectual 420 points

Thanks!

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TPS82130: Enable pin logic