Looking for a 5v to 3.3V, 500mA regulator high efficiency

[rprodrigues]

Hi all,


I would like to receive your suggestions for and simple 5v to 3.3V regulator with output of 500mA, high efficiency and within DIP or TO packages.

DC-DC converters with inductors are not welcome.

I found MAX604, but I think it is too expensive (about $ 4 per unit).


Any suggestions?

Thank you,
RPR

 

[FvM]

You're on a wrong track.

All linear regulators have basically the same efficiency (except for small differences caused by the quiescent current). It's about 65 % in your case.

Only regulators utilizing an energy storage can achieve a higher efficiency. These are first of all your unwanted inductive buck converters. In principle, also a fractional switched capacitor circuit can convert 5 to 3.3V, but it's somewhat complex, and as far as I know, not available for 500 mA current level. National LM3351 is working up to 50 mA. So you are stuck with inductive converters or poor efficiency.

 

[mandar_mahajan]

Re: Looking for a 5v to 3.3V, 500mA regulator high efficienc

LM117 & LM317 are 5v to 3.3v converters.
Search their datasheets to find package no. which will meet ur spects.

 

[FvM]

By specification, standard regulators as LM117 can't guarantee the required low dropout voltage. A low-dropout type
as LM1117 is required for 5 to 3.3V. Personally, I would prefer a today's type, that doesn't bring up stability issues with
low-ESR output capacitors.

As already mentioned, the efficiency can't be higher than 65%, so if low power is an objective, a switching regulator
should be considered.

 

[rprodrigues]

Thank you guys.

I'm going to use a switching regulator so I can reach a efficiency higher than 65%!


Thank you.

 

[satishkumar]

Dear All,

what is the basic difference between Switching regulators and switching controllers?

DC/DC CONV.

thanks in advance!

rgds
sh

 

[FvM]

In common usage of terms, a switching regulator is a switching controller with an integrated switch.

 

[rprodrigues]

Re: Looking for a 5v to 3.3V, 500mA regulator high efficienc

Dear All,

what is the basic difference between Switching regulators and switching controllers?

DC/DC CONV.

thanks in advance!

rgds
sh

By the way, the family LM2675 is a great family for this kind of regulators! Try them!

Added after 14 seconds:

Dear All,

what is the basic difference between Switching regulators and switching controllers?

DC/DC CONV.

thanks in advance!

rgds
sh

By the way, the family LM2675 is a great family for this kind of regulators! Try them!

 

[hameeds01]

Re: Looking for a 5v to 3.3V, 500mA regulator high efficienc

try this one LM3940

 

[jchan172]

You can use a National Semiconductor (now TI) LMZ10500. This is up to 95% efficient, and at least 80% efficient at 600 mA.

 

[mtwieg]

You can use a National Semiconductor (now TI) LMZ10500. This is up to 95% efficient, and at least 80% efficient at 600 mA.

I've used these, and while they are quite nice, you have to be very good at soldering with an air gun to avoid damaging them during the soldering process. They're among the most difficult packages I've ever worked with, including BGA and LGA packages. But anything larger (like a LMZ10503) will also be more expensive.