TPS5420: BOOT to PH voltage is outside the Absolute Maximum Rating

Joachim Jauert

Part Number: TPS5420

Hi,

we are using TPS5420 in 6 applications to step-down 24V from a power supply to 5V. The TPS5420 works in all these applications without any problems for many years. After receiving PCN#20240424000.1 I checked the BOOT to PH voltage at two of these applications. I measured a maximum of 9,3V and a peak voltage of up to 10.14V. The Absolute Maximum Rating for the BOOT to PH voltage is 10V (@ Datasheet Rev.E) and will be reduced to 6V (@ Datasheet Rev.F). We are using 0.01 μF X7R BOOT Capacitor as recommended by TI. So I don't understand why the BOOT to PH voltage is outside the Absolute Maximum Ratings. I 'm serious concerned about this situation. What is the reason for this situation and what has to be done? To change all of our designs would cause us a lot turbel.

Thank you in advance for your time,

Joachim

2 months ago

0 Jimmy Hua 2 months ago

TI__Guru 50120 points

Hello Joachim,

I am gather information with the internal team look into this and come back to with an appropriate response.

Regards,

Jimmy

0 Robert Blattner 2 months ago

TI__Expert 6205 points

Hello Joachim,

The datasheet specification applies to externally applied voltage. Since some varieties of the chip run with a 5 V BOOT voltage and others with 10 V BOOT voltage, as a group, more than 6 V should not be applied to the pin. Since all varieties are safe with internally generated voltage, there is no problem if 10 V is generated by the IC.

Regards, Robert

+1 Joachim Jauert 1 month ago in reply to Robert Blattner

Prodigy 10 points

Hello Robert,

thank you for your answer. It resolved my issue.

Regards, Joachim

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TPS5420: BOOT to PH voltage is outside the Absolute Maximum Rating