LM5158: 15V In 48V?

Graham North1

Intellectual 355 points

Part Number: LM5158
Other Parts Discussed in Thread: , LM5157, LM5156, LM51561

Hi,

I'm looking to design a 15V in, 48V out boost circuit.

I've looked at the following parts:

LM5158

LM51581

LM5157

LM51571

LM5156

LM51561

I have a few questions:

* The LM51581 has the lowest Peak Current rating (1.63A), what would be the maximum output current I could get out of this design?

* If I do a design for the LM5158/1, can I substitute the LM5157/1 if needed?

* Any reason to go for the LM5156/1 over the 57 or 58?

* Low noise on the output is important, do you have any resources to help with reducing it?

Thanks,

over 2 years ago

0 Stefan Schauer over 2 years ago

TI__Mastermind 48961 points

Hi Graham,

thank you for using the E2E forum.

The output current depends on the whole system. A good evaluation can be done by using the quickstart calculator, which is provided on the product pages, like:

LM5158 data sheet, product information and support | TI.com

The LM5158 can be replaced by the LM5157 if you consider the resistor which needs to be at the VCC pin of the LM5157 (just use a 0 Ohm for the LM5158).

The LM5156/5 will give you more flexibility on the driver MOSFET (as it is external) - so higher power / higher voltages can be reached here.

The power design seminar series is a great source of information, here you can also find some low noise presentation:

Power supply design seminar | Resources | TI.com

Best regards,

Stefan

Power management

Power management forum

LM5158: 15V In 48V?