Suitable Replacement?

Is this

A suitable throughole replacement for this

As used in the typical application curcut shown here.

Am building switch mode 5v power supply to power Arduino.

Thank You.

Going from Ac to Dc?
Or Dc to Dc?

AC to DC. The drawing shows this component to be on the DC side it looks like.

Thank You.

Why not just use the same part?

For 5v output for example.
Big leads, easy to solder.

Because I plan to breadboard it first :slight_smile: Maybe switch to SMT for the final design but much testing to do first.

So solder it on a couple of male header pins. Try and get as close to the final parts as you can.
Switching power supply components seem to always warn in the application area to keep traces short, etc. Thus not sure how well breadboading will work out if you intend to use solderless breadboard. Building up on perfboard might work better.

I just want to make sure it actually works and doesn't blow up before I go to the headache of the perf board stage :slight_smile: I have never built one of these before and I only understand it at a very rudimentary level. I want to study it with my scope while it's working and see what happens at the various nodes etc. I have seen some vids of these things blowing up if you don't have that zener in place for example :slight_smile: Fun...but not useful LOL :slight_smile:

I can't even find that you can buy the control chip separately:

Must not be using the right search terms.

This is what I bought and from whom :slight_smile: I have it in my hot little hand but as I am a newb to building my own boards I forgot you can;t just buy an IC. You have to buy all the stuff that goes with it.

That is a complete AC/DC adapter tho.
Are you saying you can’t pick the components from Table 2 to finish?
Or, you are trying to swap in different components?

My recommendation: Go with what is in Table 2.

I am trying to go with table 2. that is the smart thing to do. I would like a through hole zener though. Also having trouble finding the exact parts for the MOV1 and NTC from Digi-Key. I don't want to pay 20$ in shipping charges ordering from 3 different vendors etc :slight_smile:

Thank You

I would think as long as you are reasonably close (+-10%) on the parameters you will be just fine. The NTC Thermistor is designed to limit the inrush to the supply, so as long as you get an equivalent unit you'll be OK.

As for the MOV on the input, that is designed to catch spikes on the input line, so if your supply is rated for 265V input, you should find an MOV between 270 and 330V. In reality on a house line at 115V it will never come into play.

The TVS diode on the output is designed to limit spikes on the 5V line from backfeeding into the power supply. I've never heard of an Arduino causing those kinds of spikes, so you could leave it off.

Remember they are showing you how to incorporate their product into your design and they want you to have the most robust circuit possible. That's why all the protection.

rmetzner49 :slight_smile:

There are some cool video's on you tube about what happens if you take that diode out while operating a switch mode power supply :slight_smile: Trust me, you need it.

Check this out :slight_smile:

The fun is about at 1:50

Different diode. Obviously the external diode is exactly what note 5 implies:

C4 is a ceramic capacitor which is used to fi lter high frequency noise. C2, C3 and L1 form a pi-type fi lter circuit. For current of L1 and L2 refer to the datasheets provided by
the manufacturers, current derating should be 80% or above. TVS is a recommended component to protect post-circuits (if converter fails). We recommend using a 5D-9
external input NTC.

I'm sort of disappointed they didn't see fit to include all those extra components in the base module.

Maybe it wouldn't fit :slight_smile: But I must say....It would have been nice. It's a very thin IC so maybe they felt it would just add too much size. I don't know. When I bought it I was hoping it was all included. It does bring the amount of components for a switching power supply down to about the number of the ones you would need for a linear one. That is a nice improvement, Those SOB's get complicated fast.