LM5017: Minimum Vin

Kuan Wei Chen (Kevin Chen)

Part Number: LM5017

Dear Team,

Delta decided to use LM5017 as the 12V auxiliary power supply in the product

But found that the voltage limit of Vin pin and UVLO pin is -0.3V~100V
Almost all Clamping diodes cannot meet the -0.3V protection requirements.

We want to make sure whether these two Pin voltages can withstand -0.3V ~ -0.7V?

Or how to deal with it to protect the device

Kevin

over 3 years ago

0 Daniel Li14 over 3 years ago

TI__Mastermind 27030 points

there is internal ESD diode in the Vin and EN , if there is negative lower than -0.3V, it will conducted and sink current which will damage the ESD diode.

normally, when applied the voltage on Vin and EN it should be positive, why customer system will have negative voltage on it?

Thanks

0 Kuan Wei Chen (Kevin Chen) over 3 years ago in reply to Daniel Li14

TI__Genius 9710 points

Dear Daniel,

They will put a diode before the input to prevent the negative voltage input.

So when the input have negative voltage, the diode will conduct so the diode's forward will be around -0.4~-0.7V

Or do you have better ideas how to protect the negative input voltage?

Kevin

0 Daniel Li14 over 3 years ago in reply to Kuan Wei Chen (Kevin Chen)

TI__Mastermind 27030 points

Hi Kevin:

I have loop you in the email, pls wait for the team's feedback.

Thanks

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LM5017: Minimum Vin