TPS709: EN threshold

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS709

Hi,

My customer is evaluating TPS70933.

EN threshold is certified as follows.

However output voltage rises up when VEN is 0.5V as follows.

※This waveform is same with actual

This schematic is follows.

Why does output rise up at EN=0.5?

Best Regards,

Kuramochi

over 6 years ago

0 JCHK over 6 years ago

TI__Mastermind 43690 points

Hi Kuramochi-san,

The Enable pin has its own internal pull-up typically ~300nA. So if left floating it would automatically enable. I think if you use an oscilloscope to see the actual Enable threshold, it should be closer to 0.9V. Please note; the 0.9 Minimum means above 0.9V we guarantee that the device is enable. below 0.4V we can guarantee that it will be off. Between 0.4 and 0.9 is actually undefined. Does this answer your question?

Regards,

0 Kuramochi Tadahiko over 6 years ago in reply to JCHK

Guru 28715 points

John-san,

Thank you for your answer.

I have an additional question.

Does VEN threshold have hysteresis?

Best Regards,
Kuramochi

0 JCHK over 6 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 43690 points

HI Kuramochi-san,

Let me check with our designers on how much hysteresis we have on the VEN threshold.

Regards,

0 Kuramochi Tadahiko over 6 years ago in reply to JCHK

Guru 28715 points

Hi John-san,

Thank you for your support.

I have an additional request.
Could you share the dispersion data of EN threshold for our reference?

Best Regards,
Kuramochi

0 JCHK over 6 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 43690 points

Hi Kuramochi-san,

Based on simulation data, the nominal hysteresis for enable is 23mV. Over the full temperature range the minimum would be 21mv and the maximum would be 27mV.

Does this answer your question?

Regards,

0 Kuramochi Tadahiko over 6 years ago in reply to JCHK

Guru 28715 points

Hi John-san,

Thank you for hysteresis information.
I wait also the dispersion data of EN threshold.

Best Regards,
Kuramochi

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TPS709: EN threshold