TPS7A57: Enable Pin Voltage

SSC

Part Number: TPS7A57

I am trying to set the threshold for turning on the regulator using equation 1 and 2 in section 8.1.1 of the datasheet. But I am not seeing the voltage for the Enable pin in the datasheet. I see values for VIH(EN) and VHYS(EN), but not V(EN). What is the value of V(EN) and where can I find in the datasheet?

7 months ago

0 Stephen Ziel 7 months ago

TI__Mastermind 32955 points

Hello,

The typical threshold voltage for the enable pin is 650mV. You can see that in the EC table, copied below:

Thanks,

Stephen

0 SSC 7 months ago in reply to Stephen Ziel

Prodigy 95 points

If you look at eq 1 and 2 in the datasheet, you will see the equations:

The spec you called out is VIH(EN). What I need is VEN.

0 Stephen Ziel 7 months ago in reply to SSC

TI__Mastermind 32955 points

VEN is the voltage you wish to apply to the enable pin in your application.

Thanks,

Stephen

0 SSC 7 months ago in reply to Stephen Ziel

Prodigy 95 points

That doesn't seem correct. Let me ask it another way and you can tell me what values to plug in. I would like to turn ON at 3.1V and turn off at 2.85V. Please provide example values for the equations 1 and 2.

0 Stephen Ziel 7 months ago in reply to SSC

TI__Mastermind 32955 points

Hello SSC,

I will reply to your latest question within 3 business days.

Thanks,

Stephen

0 Stephen Ziel 6 months ago in reply to Stephen Ziel

TI__Mastermind 32955 points

Hello SSC,

We are taking another look at these equations and we see your concern. If possible I will have an update for you tomorrow but it may extend into early next week. Thank you for your patience.

Thanks,

Stephen

0 SSC 6 months ago

Prodigy 95 points

I believe there is an error in the equation 1. In that equation, I believe VIH(EN) is the same as VEN. This should be corrected in the datasheet as it causes confusion.

+1 Stephen Ziel 6 months ago in reply to SSC

TI__Mastermind 32955 points

Hello SSC,

I think you are correct.

To be sure, I tested an EVM with a 100mHz triangle pulse to fact check where the LDO turned on and off. The EVM does not have any resistor dividers tied to the EN pin. The LDO turned on when the enable pin voltage reached 650mV and turned off when it reached 608mV. This sample of one measurement corresponds well to the equation 1 if Ven is a typo and should be Vin(en). I've added this to our datasheet correction log and we will update this during the next revision of the datasheet.

Thanks,

Stephen

0 SSC 6 months ago in reply to Stephen Ziel

Prodigy 95 points

Thanks for the confirmation, Stephen. I will mark this issue as resolved.

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TPS7A57: Enable Pin Voltage