MC34063ACD-TR

[AndrewFFFF]

Hello

Anyone did ever you use the MC34063ACD-TR for to power on a "MCU" at 3.3V?

From datasheet it seems it needs change R1 and R2 for to obtain the goal but the figure 15 shows until 5V so..I ask you if i can use it for my application.

My application is to convert  from 24V to 3.3V.

[Peter BENSCH]

Of course, the MC34063 can also be used to generate 3.3V, primarily only the resistors to the pin feedback need to be adjusted. The application in the data sheet focusses on 5V because it is already very old and 5V was the predominant supply voltage at that time.

Hope that helps?

Good luck !
/Peter

[AScha.3]

Hi,

yes, i made a supply using MC34063 , 24 -> 3v3 ; running fine, just the main cap at 3v3 i used a dry polymer "elko" and some 10uF cer.caps , to have low ripple for long time .

Just calculate R1/R2 for the voltage you want. (and the coil: high saturation current + shielded type preferred.)