TPS61169: SW Negative Voltage

Koshi Ninomiya

Part Number: TPS61169

Tool/software:

Dear Team,

My customer is evaluating the TPS61169 at LCD Panel LED Backlight driver application. And they measured around -1.3V negative undershoot voltage at SW pin which is larger than -0.3V of absolute maximum rating.
Applicaion circuit:
*Note: Snubber circuit at SW pin is mounted

Measurement waveform of SW pin:
*Note: SW pin to GND pin shortest wire probing

Is thie around -1.3V negative undershoot voltage at SW pin no problem?

Best Regards,

Koshi Ninomiya

5 months ago

0 Suchen Dong 5 months ago

TI__Expert 4781 points

Hi Koshi,

Our expert will reply to you later. Thanks for your patience!

0 Koshi Ninomiya 5 months ago in reply to Suchen Dong

TI__Expert 5655 points

Hi Dong-san,

My customer looks forward to your response.

Best Regards,

Koshi Ninomiya

0 Suchen Dong 5 months ago in reply to Koshi Ninomiya

TI__Expert 4781 points

Hi Koshi,

Sincerely sorry that our expert is OoO this week. Thanks for your patience.

+1 Hongjia-Wu 5 months ago in reply to Koshi Ninomiya

TI__Expert 7380 points

Hi Koshi-san,

Thank you for your patience.

The minimum voltage rating of -0.3V found in the data sheet is actually a dc rating and means that the part could be damaged if a constant voltage below –0.3 V is applied at the SW node from a source. In your case here, -1.3V only lasts for several ns or tens of ns and it's very short duration and will be no damage to the device.

Regards,

Hongjia

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TPS61169: SW Negative Voltage