Basic Liner power supply

[kkdelabaca]

Hello,

I'm designing a very basic power supply. The input voltage is 5Vdc and the output is for 3,3Vdc and 250mA.

**broken link removed**

Can anyone tell me what are the basics elements to protect my electronics from external interferences and other protections(filters, fuses,...)?
I accept any suggestions.

Thanks!

kkdelabaca

 

[cmontoya]

this looks fine, I didn't look at the datasheets, You should make sure the TVS is rated for a fair amount over 5 volts say 8 volts or so, assuming you have voltage ripple on your input voltage. Also make sure your caps are rated to the right voltages double if their tants. You have a lot of caps on the output make sure your linear reg can handle that most can.

 

[fisher101]

hye
well what you have pasted is certainly a orcad design kindly simulate your design in pspice or proteous

fuse: more over u can use a diode from pin 2 to pin 3 wich will certainly stop any reverse current

u have added alot of capistors which is not required untill you want your output to be really very smooth kindly remove one cap from out put u will se in simulation that this does not make any difference

suggestions : add a potentiometer at the out put to make it a veriable powersupply

 

[enjunear]

Hello,

I'm designing a very basic power supply. The input voltage is 5Vdc and the output is for 3,3Vdc and 250mA.

**broken link removed**

Can anyone tell me what are the basics elements to protect my electronics from external interferences and other protections(filters, fuses,...)?
I accept any suggestions.

Thanks!

kkdelabaca

Agree with cmontoya on the cap voltage ratings. Also agree w/ fisher on the protection diode and output caps (look at the manuf. spec sheet and match their capacitance on the output until you have good reason to deviate from that recommendation). If your device doesn't have self-protection (self-overheating, overcurrent protection), then I'd add a series fuse right after the connector (slo-blow or fast-blow depends on your application).