LM3492: DIM Input Level

Hirotsugu Kobayashi

Mastermind 9025 points

Part Number: LM3492

Hi, team

Can DIM pin be connected with VCC directly?

Because the absolute maximum rating of DIM1 and DIM2 pin are 6V, but the maximum of Vcc is 6.3V.

Best Regards,

over 7 years ago

0 Clinton Jensen over 7 years ago

TI__Mastermind 25500 points

Hello Hirotsugu,

It would be safe if you use a 52.3k resistor between VCC and DIM1/DIM2 just as you do with COMM. That would limit any pin current to a very low value in the case VCC exceeds 6V. I cannot say it would be safe to tie directly to VCC given the 6.3V max spec.

Regards,

Clint

0 Hirotsugu Kobayashi over 7 years ago in reply to Clinton Jensen

Mastermind 9025 points

Hi, Clint.

Thank you for your answer.
The DIM pin and VCC pin are connected directly by this AN.
www.ti.com/.../snoa568a.pdf
Is this OK?

Best Regards,

0 Clinton Jensen over 7 years ago in reply to Hirotsugu Kobayashi

TI__Mastermind 25500 points

Hello Hirotsugu,

I am not sure who did that app note but it's probably safe considering the guardbanding put around min/max limits. However if directly connected and either DIM pin fails for some reason it would not be considered a defective IC considering the spec and the possibility of violating abs max. I would still recommend using a resistor to limit any current into the pin if the 6V abs max is exceeded. That would ensure you never have to worry about damage.

Regards,

Clint

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LM3492: DIM Input Level