TPS274160: Ripple is applied on Vs pin and Vout pin before 12V Vs is applied

Hisao Uchikoshi

Part Number: TPS274160

Hi Experts,

Due to customer's external components, about 50KHz 3.5Vp-p ripple is applied to Vs pin and Vout pin for 1 second. EN pin is pulled high with 3.3V. After elapsing 1 sec, 12V is supplied to Vs pin. At that time, Vout is 12V with enabled EN pin. We do not think this violates abs max of HS switch. Below is the waveform.

Are there any concerns for that the voltage ripple is applied on VS pin and Vout pin?

Regards,

Uchikoshi

over 3 years ago

0 Yichi Zhang. over 3 years ago

TI__Genius 16390 points

Hi Uchikoshi-san,

I saw the max and min during the ripple is 1.4 to 5.9V, is that correct?

If that's the case, the 1.4V input might trigger the UVLO since the UVLO threshold is around 3V. The device will shut down during that scenario. Please let me know if this is the case. Thanks!

Regards,

Yichi

0 Hisao Uchikoshi over 3 years ago in reply to Yichi Zhang.

TI__Genius 14850 points

Hi Yuchi,

Thank you for your investigation. Do you think if this VS ripple (UVLO ON/OFF) affects the device reliability?

Regards,

Uchikoshi

+1 Yichi Zhang. over 3 years ago in reply to Hisao Uchikoshi

TI__Genius 16390 points

Hello Uchikoshi-san,

It shouldn't affect the reliability, but you need to check with customer if unintentional turn off is acceptable in their application.

Regards,

Yichi

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TPS274160: Ripple is applied on Vs pin and Vout pin before 12V Vs is applied