# Voltage on Notecarrier B EN pin

**URL:** <https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746>\
**Category:** Hardware\
**Created:** [March 29, 2022, 12:17pm UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746 "2022-03-29T12:17:31Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [March 29, 2022, 12:17pm UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/1 "2022-03-29T12:17:31Z")

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Hi,

how much voltage can be applied to the EN pin? Can it be the same as V+ or does it need to be 3V3? Is the voltage on VIO on when EN is LOW? So that I could use VIO as the level for EN?

Regards, Gaute

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**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\
**Post date:** [March 31, 2022, 12:23am UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/4 "2022-03-31T00:23:04Z")

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The `EN` pin is designed to float in the enable case, and to be driven to ground when you wish for it to be disabled. Think of it as a disable switch.

Will this work in your application, or is it a requirement to apply voltage?

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [March 31, 2022, 7:30am UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/5 "2022-03-31T07:30:54Z")

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Doh! Yeah of course, that solves it. I noticed the VIO voltage is at something like 0.4V when EN is off. Will it drain or does it drop once a load is added to it?

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**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\
**Post date:** [March 31, 2022, 9:59am UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/6 "2022-03-31T09:59:01Z")

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Yes, it slowly drains away. It’s a side-effect of the low-power design.

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<div class="post-metadata">

**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [March 31, 2022, 11:09am UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/7 "2022-03-31T11:09:59Z")

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Great! So just to be clear: I wont leak any power by having a load attached to VIO once EN is connected to ground?

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<div class="post-metadata">

**Author:** ![zfields](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/zfields/32/29_2.png) [@zfields](https://discuss.blues.com/u/zfields)\
**Post date:** [March 31, 2022, 11:15am UTC](https://discuss.blues.com/t/voltage-on-notecarrier-b-en-pin/746/8 "2022-03-31T11:15:38Z")

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Yes, that is correct.