24v to 5v and 3.3v conversion

[gsg]

Hi,
(I don't know if I'm posting this in the right forum... But please help)

I'm designing a microcontroller circuit with all ICs working on 3.3v. Only one IC (L289) requires a 5V supply. The power for the whole circuit is supplied from a 24V battery.
I was think of using a 7805 to give convert 24v to 5v and then give the same output to a 3.3v regulator (LE33).
Can someone tell tel if this will work? If not how can I convert 24v to 3.3 and 5v?
Please help..


-gsg

 

[IanP]

If you use linear voltage regulators to drop fro 24V to 5V (and/or 3.3V) you’ll be loosing a lot of power converted into heat ..
Instead of linear regulator you may consider switching regulator which is pin-compatible with the LM7805, namely the DE-SW050 and then you can use LDO to drop from 5V to 3.3V, or you can use another switching regulator - DE-SW033 – to drop voltage directly from 24V to 3.3V ..
More info is at:
https://www.dimensionengineering.com/DE-SW0XX.htm

Rgds,
IanP

 

[Kripton2035]

you can also use a specialized circuit with 2 outpouts like this one :

https://www.ti.com/lit/gpn/tps54286

 

[cameo_2007]

also you can look for,

LM2676 - 5
LM2676 - 3.3

 

[Tahmid]

Hi,

For switching regulator, take a look at L4971. It is available in 8-pin DIP package. It is capable of 1.5A output current.
https://www.st.com/stonline/products/literature/ds/5598.htm

Hope this helps.
Tahmid.