24VDC to 5VDC @100 ma (optimum solution)

[lozzik]

+24vdc to +5vdc converter

Hi everybody,

I have 24VDC at my circuit and i need 5 V DC 100ma, and i have space problem, it has to be with minimum space requirements.

When i use LM7805 it needs a heatsink, but dont have enough space for heatsink.
I tried LM7815 and than LM7805 it still gets hot. I tried with resistor and than 7805 i still get the heating problem.

I am thinking to use some switching solution but in that case i have to use a big coil.

And there are some DC/DC converter modules but they are quite expensive (cheapest i found is 5 USD)

Does any one has any recommendations.

Thanks.

 

[VVV]

24vdc to 5v dc switching regulators

You will have to use a switching regulator. The cheapest I can think of is the LM3485 from National. The size of the inductor is determined by the current and switching frequency. You can probably get away with a reasonably small one.

An LM2594 is also a good choice, since it does not require any transistor.

 

[eem2am]

tl497 heat sink

or got to national fairchild www


they have speadsheet you fill out your requirement, and they give you solution.

allso linear.com

also what about TL497?

THAT I SVERY SIMPEL no loop compensation.

maybe you look for hysteretic controller..as you dont worry about your loop compensation.

for 2.5W surely nobody would want to bother with loop compensation?

yes and i agree maybe is best you get onchip transsitor...save space.

so on/off control or hysteretic mode is the way.......unless you like bode plots and can work out modulator transfer functions

 

[mrcube_ns]

24vdc to 5vdc

Look this:

**broken link removed**


Regards,

Mr.Cube