LM5176-Q1: RT, VISNS, VOSNS pin's sink/source current

Weixu Pan

Prodigy 80 points

Part Number: LM5176-Q1

Tool/software:

Hi Team,

I would like to inquire RT, VISNS, VOSNS pin's max sink/source current to do the worse case analysis.

I don't find it in the datasheet.

These pin connect to the external resistor, it will be some current on it.

Could you please help to provide it or provide the current level?

Thank you.

5 months ago

0 Stefan Schauer 5 months ago

TI__Guru 58641 points

Hi Weixu,

will try to get this parameter but will take a few days.

Will give you an update latest mid of next week.

Best regards,

Stefan

+1 Stefan Schauer 5 months ago in reply to Stefan Schauer

TI__Guru 58641 points

Hi Weixu,

The VISNS and VOSNS input current are limited by a 500k resistor to ground. Tolerance is +/-20%.

For the RT pin the current is defined by the allowed resistors which can be connected to this pin. In worst case this current might increase up to 1.2mA

Best regards,

Stefan

0 Weixu Pan 5 months ago in reply to Stefan Schauer

Prodigy 80 points

Hi Stefan,

Is the RT pin's current related to the resistance value?

If we connected 20K ohm to ground, what will the current value be?

thank you.

Will

0 Stefan Schauer 5 months ago in reply to Weixu Pan

TI__Guru 58641 points

HI Weixu,

the Rt pin will provide a voltage of ~ 1.2V and adjust the frequency bases on the current defined by the attached resistor.

Can you explain me for what worst case analysis this information is required? Thanks.

Best regards,

Stefan

0 Weixu Pan 5 months ago in reply to Stefan Schauer

Prodigy 80 points

Hi Stefan,

RT pin connected 20k ohm to ground, we need to check the resistor's power rating is sufficient after considering de-rating.

I believe the current through the resistor is provided by the RT pin.

So we need the current or voltage to calculate power dissipation.

Weixu

+1 Stefan Schauer 5 months ago in reply to Weixu Pan

TI__Guru 58641 points

Hi Weixu,

Thanks,

So lets add some margin and use 1.5V with 20k -> gives ~ 115uW - should not be an issue for any resistor.

Best regards,

Stefan

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LM5176-Q1: RT, VISNS, VOSNS pin's sink/source current