TPS62745: Create a negative voltage.

Kengo.Y

Part Number: TPS62745

Hi team,

I have confirmed before about negative power generation on the bellow thread.

My customer wants to change input voltage 8V from 3.3V.
Is it okay to think that the input voltage is 11.3V because the output is -3.3V(negative voltage)?
I think they should change the input conditions.
Since it is a negative voltage, let me check it.

Sincerely.
Kengo.

over 3 years ago

0 Vincent Zhang(BSR) over 3 years ago

TI__Expert 4795 points

Hi Kengo,

For a 8V->(-3.3V) buck boost, it could be considered as 11.3V->3.3V buck, so TPS62745 whose Vin_max is 10V is not suitable here. You may need to choose a 17V parts. Most Buck converter could be configured as negative buck-boost converter.

0 Kengo.Y over 3 years ago in reply to Vincent Zhang(BSR)

Guru 10385 points

Hi Vincent,

Thank you for your reply.

What kind of operation can be considered when the input voltage exceeds the recommended operating range?

And then,do you have a super low Iq device same as TPS62745?

Sincerely.
Kengo.

0 Vincent Zhang(BSR) over 3 years ago in reply to Kengo.Y

TI__Expert 4795 points

Hi Kengo,

If input voltage exceeds the recommend voltage, the device may be damage.

Sorry we don't have <1uA level >12VIN device in portfolio now.

0 Kengo.Y over 3 years ago in reply to Vincent Zhang(BSR)

Guru 10385 points

Hi Vincent,

Could you tell me where the damage will be?

Sincerely.
Kengo.

0 Vincent Zhang(BSR) over 3 years ago in reply to Kengo.Y

TI__Expert 4795 points

Hi Kengo,

The internal FET will be damaged, It will exceed the SOA and cause EOS. Thanks.

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TPS62745: Create a negative voltage.