requirement for LDO

LM317 has good power packages.

Good thermal performance of the package is just half the task. Once the heat is out of the package it must flow into something else; air , circuit board , heat sink. Area is the key.

Hi Ron-san,

Thank you for your suggestion.
Is there similar thermal performance device that has enable pin?

Best Regards,
Yaita

Is there a requirement that this must be pre-set (fixed) 5.5V? Is adjustable type allowed?

Is the maximum operating ambient temperature (Ta) defined? That will determine the maximum Theta(ja) needed.

If the max operating Ta is 25C and max allowed operating Tj is 125C, then Theta(ja) needs to be 37C/W, or lower. You will need a thermal tab, or exposed thermal pad, to get that low. That's probably going to be WSON or TO-263.

I'd suggest Webench designer, or the Parametric Search tool, but they don't allow sorting on package thermal resistance, just the generic package type. Webench designer does take thermal dissipation into consideration to eliminate some parts from the list.

 

If adjustable is OK, then here is one that might work, there are probably others ....
TPS7A4501 - Theta(ja) for KTT package option is 28C/W
Keep in mind that the PC board is the heat-sink for this package.

www.ti.com/.../single-channel-ldo-products.page;5.7&p182=Adjustable Output&p1342=Enable&p451max=0.6;7.5&p238max=10;36&p634max=5.5;34&p634min=1;5.5

LDO adjustable 5.5V >0.6A >=10V input