TPS61041-Q1: When FB was short-circuited to GND

Koji Hayashi92

Mastermind 6970 points

Part Number: TPS61041-Q1

Hi All,

What happens when FB is shorted to GND?

Is the IC broken?

I think that the output voltage rises and exceeds the withstand voltage of the SW pin.

Best Regards,
Koji Hayashi.

over 6 years ago

0 Helen chen over 6 years ago

TI__Mastermind 40080 points

You're right. if FB shorted to GND. Vo will rise to a very high level, the output diode and the internal FET will be damaged.

0 Koji Hayashi92 over 6 years ago in reply to Helen chen

Mastermind 6970 points

Hi Helen-san

Thank you for response.

Is there a countermeasure method?

Best Regards,
Koji Hayashi.

0 Helen chen over 6 years ago in reply to Koji Hayashi92

TI__Mastermind 40080 points

Please check the atatched file, hope this one can help you.slva227.pdf

0 Koji Hayashi92 over 6 years ago in reply to Helen chen

Mastermind 6970 points

Hi Helen-san

Thank you for quick response.

I will develop information to customers

Best Regards,
Koji Hayashi.

0 Koji Hayashi92 over 6 years ago in reply to Koji Hayashi92

Mastermind 6970 points

Hi Helen-san

How do I select a Zener diode?
What is the characteristic you care about?
Is there a calculation formula?

Best Regards,
Koji Hayashi.

0 Helen chen over 6 years ago in reply to Koji Hayashi92

TI__Mastermind 40080 points

What is the maximum LED Vf in your applicaiton. Generally Vzener should >(VLEDamx+VFB) at any condition. No other special requirement.

0 Koji Hayashi92 over 6 years ago in reply to Helen chen

Mastermind 6970 points

Hi Helen-san

Thnak you for response.

My customer don't use LED.

For example, when using 20V setting, is it sufficient to set 20V + 1.233 V> Vzener ?

Is it OK to recommend one with low reverse leakage current considering efficiency?

Best Regards,
Koji Hayashi.

0 Helen chen over 6 years ago in reply to Koji Hayashi92

TI__Mastermind 40080 points

if the Vo is 20V, then they could use a 24V -27V rating zener in their design. make sure Vzener is always higher than the maximum Vo. We also didn't familar with the zener, suggest them to ask for zener vendor for help.

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TPS61041-Q1: When FB was short-circuited to GND