LM25145: 25145

Syed Shahnawaz

Prodigy 70 points

Part Number: LM25145
Other Parts Discussed in Thread: LM5143-Q1

Hi,

I am using this controller LM25145 for my design. My input voltage is 12V and output is 5.2V with 30A load current.

This IC has current limitation of 20A . So someone here recommended me to use 2 phase for that much load current.

Can someone here guide me with that how do I achieve that as I have no idea of 2 phase thing.

Thank you

over 6 years ago

0 Robert Blattner over 6 years ago

TI__Expert 6245 points

Hello Syed,

I am looping in someone who has a lot of experience with this product and multi-phase designs.

Regards, Robert

0 Timothy Hegarty over 6 years ago

TI__Guru 73052 points

Hi Syed,

The LM25145 has no theoretical current limitation, but 20A is a typical thermal limit. Please consider the LM5143-Q1 controller to implement a two-phase design at 5.2V/30A. There is a quickstart file available in the product folder to assist with component selection.

Regards,
Tim

0 Syed Shahnawaz over 6 years ago in reply to Timothy Hegarty

Prodigy 70 points

Thank you for your response. Can I implement this without using two-phase design?

0 Timothy Hegarty over 6 years ago in reply to Syed Shahnawaz

TI__Guru 73052 points

Hi Syed,

Two phases is preferable as you get the benefit of ripple current cancellation (particularly as the duty cycle is close to 50%), but you could do it with one phase using paralleled FETs.

Regards,

Tim

0 Syed Shahnawaz over 6 years ago in reply to Timothy Hegarty

Prodigy 70 points

Hello Tim,

So Should I go head with LM25145 for my design? I mean using one phase for 30A current or should I switch to LM5143-Q1?

Thank you

0 Timothy Hegarty over 6 years ago in reply to Syed Shahnawaz

TI__Guru 73052 points

Hi Syed,

You can use the quickstart calculator for each controller to estimate efficiency and component power losses. If 30A is a short-term condition or if the max ambient temperature is low, then the LM25145 with paralleled FETs may be feasible. However, the two-phase solution is generally more practical and will provide better efficiency and heat spreading.

Regards,

Tim

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LM25145: 25145