TPS3897: EN threshold voltage

Johnny Guo

Expert 4910 points

Part Number: TPS3897

Hi, Team,

I just want to ask what is the accurate EN threshold of TPS3897?

We need to use the EN voltage to monitor another voltage rail.

Thanks.

Johnny

over 6 years ago

0 Michael_DeSando over 6 years ago

TI__Genius 12630 points

Hi Johnny,

The V_IL (low-level input voltage meaning the voltage for EN to be considered "low") is 0.4V and under.

The V_IH (high-level input voltage meaning the voltage for EN to be considered "high") is 1.4V and above.

Both of these specs are guaranteed across all operating conditions and provided in the Electrical Characteristics table 7.5 in the datasheet for your future reference.

Please let me know if you have any additional questions or need any additional support. Thanks!

-Michael

0 Johnny Guo over 6 years ago in reply to Michael_DeSando

TI__Expert 4910 points

Michael,

Yes I know EN_IH and EN_IL, I was just asking whether there is an accurate EN threshold voltage?
Thanks.

Johnny

0 Michael_DeSando over 6 years ago in reply to Johnny Guo

TI__Genius 12630 points

Johnny,

I'm not sure I understand the meaning of "an accurate EN threshold voltage". Can you please explain? Do you mean a device with a tighter tolerance or are you asking if there is a preferred voltage for EN?

-Michael

0 Johnny Guo over 6 years ago in reply to Michael_DeSando

TI__Expert 4910 points

Michael,

I mean when EN voltage rises to which voltage, TPS3897 internal logic will be enabled and work.

Thanks.

Johnny

0 Michael_DeSando over 6 years ago in reply to Johnny Guo

TI__Genius 12630 points

Johnny,

The spec you are asking is in fact the V_IH (high-level input voltage meaning the voltage for EN to be considered "high") is 1.4V and above. This is for all operating conditions. The internal logic will be enabled and work only if EN pin has 1.4V or higher.

Please let me know if this answers your question.

-Michael

0 Johnny Guo over 6 years ago in reply to Michael_DeSando

TI__Expert 4910 points

Michael,

I know EN V_IH is >1.4V, but this is only a logic HIGH range. I was asking what is the accurate EN ON and OFF threshold voltage.

Thanks.

Johnny

0 Michael_DeSando over 6 years ago in reply to Johnny Guo

TI__Genius 12630 points

Johnny,

There is no voltage spec for the exact voltage in which turns ON and OFF because of the built in hysteresis of the EN pin. That is why you must be above 1.4V for EN to be "high" and below 0.4V for EN to be "low". If you are in between, the EN will maintain the state it is already in until either 1.4V is reached or 0.4V is reached to toggle EN high/low.

-Michael

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TPS3897: EN threshold voltage