LM5085: Component Selection

OverAgent712

Part Number: LM5085
Other Parts Discussed in Thread: LM5148, LM5149

Tool/software:

Hello,
I want to design the LM5085 to give 10A at the output, can I know the component ratings for the diode, inductor, and MOSFET mainly?

Can we use multiple 0805, 0603, or smaller package capacitors for input and bypass?

For now, the DIODE chosen is rated for 15A. MOSFET is for 15A. Will that suffice?

over 1 year ago

0 EricLee over 1 year ago

TI__Guru 59331 points

Hello

It is not recommended to use LM5085 to handle 10A. Please consider to use synchronous buck controllers like as LM5148 or LM5149.

-EL

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

The datasheet mentioned that the maximum handling capacity of LM5085 is 10A.

0 EricLee over 1 year ago in reply to OverAgent712

TI__Guru 59331 points

Hello

If you are an expert of power supply design, please try. If not, please consider to use synchronous buck controllers like as LM5148 or LM5149.

-EL

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

Hello,
Can I get the answer with reasons why it can't handle 10A even though it's mentioned in the datasheet?

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

Hello,
What is the maximum output current it can support?

0 EricLee over 1 year ago in reply to OverAgent712

TI__Guru 59331 points

Hello

Since this is a controller device, the maximum output current is defined by customers.

Usually, the diode temperature exceeds the design requirement if the load current is greater than ~ 5A

-EL

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

Hello,

Okay, so the diode should be carefully selected such that it doesn't exceed the design requirement?

Is this the correct understanding?

0 EricLee over 1 year ago in reply to OverAgent712

TI__Guru 59331 points

Hello

Yes, correct. Also, if you cannot find a diode which meets your design requirement due to an excessive temperature, please consider adding a fan with heat sink.

-El

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

Hello,

As mentioned we require to get 5V,10A from the IC. Can we select the diode with 15A/20A and 60V rating for this?
And what does excessive temperature mean here? Is it that the diode heats due to the power dissipated?

0 EricLee over 1 year ago in reply to OverAgent712

TI__Guru 59331 points

Hello

Yes, that's correct.

-EL

0 OverAgent712 over 1 year ago in reply to EricLee

Intellectual 470 points

Hello,

So we need a diode that matches our ratings and has lesser power dissipation?

0 EricLee over 1 year ago in reply to OverAgent712

TI__Guru 59331 points

Hello

Yes, that's correct, but as I mentioned there is a possibility that the diode temperature exceeds your design requirements.

-EL

Power management

Power management forum

LM5085: Component Selection