LM5116: LM5116 UVLO issue

Hsu cheng

Part Number: LM5116

LM5116 application is currently a problem, need to ask about
Ruv1 from 62K to 47K, Ruv2 is 16.9K, the combination of the pressure points as shown below
Vin range of products is relatively large range of 9V to 57V, such as the use of partial pressure calculation does not produce problems
But the test unit in the 57V test, it is easy to cause no output phenomenon
After verification is D1 burned or it is hot
Want to know, UVLO voltage level and D1 What is the relationship?

over 7 years ago

0 David Baba over 7 years ago

TI__Mastermind 33080 points

Hello Hsu,

The Abs max Voltage on the UVLO is 16V. This means the voltage at the UVLO pin cannot approach this value at high vin. Please can you check. Also I am not clear what D1 is?

do you have a schematic you can share please?

Thanks.

David.

0 Hsu cheng over 7 years ago in reply to David Baba

Expert 1565 points

Hi David,

D1 is D17 BAT54A.

0 David Baba over 7 years ago in reply to Hsu cheng

TI__Mastermind 33080 points

Hello Hsu,

I would not reduce RUV1 to 14.7k as this certainly increases the Voltage on the pin very close to 16V. If you have a slightly higher voltage or ringing you will damage the device. If you want to keep the values I suggest placing a Zener Diode from UVLO pin to Gnd.

Hope this helps?

David.

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LM5116: LM5116 UVLO issue