TPD3S014: how does the part behaive when reaching abs. max rating of 6V at Vin?

KlausWawrzyniak

Intellectual 1900 points

Part Number: TPD3S014

Hello, my customer is using the TPD3S014 in an application, where at the start of the application the input voltage can raise up to 6V – just for a short period of time.

After that, the device works 24/7 all day/night. So during lifetime of TPD3S014 it will see only few of those events.

The Enable pin is low in this event.

Can you please elaborate on technical details if / how you would allow such kind of condition?

over 5 years ago

0 Michael Tan over 5 years ago

TI__Expert 8420 points

Hi,

The 6V voltage haven't exceed the max rating for IN pin. so it will not impact the behavior of the device and all feature is guarantee in the datasheet under this condition.

0 KlausWawrzyniak over 5 years ago

TI__Intellectual 1900 points

Hello, we have done more tests:

Setup: I put a resistance of 10ohm in series to the Vin pin and measured across the reistsance with a differential probe (green signal in screenshot below). In addition, the inputvoltage is shown as yellow signal. The first picture below shows under normal condition (v cross resistor abt. 10mV)

The picture below shows the condition with overshoot. The input voltage reaches abt. 6.07V, voltage across resistor abt. 5mV

Please advise on the overshoot confition. Thanks

0 Michael Tan over 5 years ago in reply to KlausWawrzyniak

TI__Expert 8420 points

Hi ,

I can't understand your setup .

Do you have any loading for this test ? You mean the overshoot is the IN pin voltage above 5.5V?

The first picture show at the beginning the voltage is zero but there voltage in the 10ohm resistor, why current can go through the device when IN is zero?

0 KlausWawrzyniak over 5 years ago in reply to Michael Tan

TI__Intellectual 1900 points

Yes, the overshoot is at the IN pin and is created by the supply we are using only after short power outages. The voltage then reaches up to roughly 6.07V.
The load for this test is not relevant as the chip is not enabled at startup.
The voltage at the beginning is not 0 because of an offset issue from the probe, sorry about that! Only the difference is relevant and indicated by the scope cursors.

0 Michael Tan over 5 years ago in reply to KlausWawrzyniak

TI__Expert 8420 points

Hi,

Thanks for explaining the setup.

The green channel is reflect the current in the test. You can find the current will cycling after device startup. As you short the output the heat will created internal and touch the OTSD ,then the device will be thermal cycling.

0 KlausWawrzyniak over 5 years ago in reply to Michael Tan

TI__Intellectual 1900 points

Yes you are right. This probably happened during soldering the 10Ohm resistor for measuring the current.

The interest however lays in the overvoltage situation while start up with voltages reaching roughly 6.07V (Yellow). Is this ok as almost no current is flowing into the IC during this time?

0 Michael Tan over 5 years ago in reply to KlausWawrzyniak

TI__Expert 8420 points

Hi,

The max voltage is 6V and the spike is 6.07V, TI can't guarantee this input voltage value.

But to my understand it should not have issue. The SPEC will have a margin for the 6V max rating.

0 KlausWawrzyniak over 5 years ago in reply to Michael Tan

TI__Intellectual 1900 points

Thank you very much for clarifying. This is actually the expected answer

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TPD3S014: how does the part behaive when reaching abs. max rating of 6V at Vin?