• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

5V Interruptible Power supply


New Member
5V UnInterruptible Power supply

I am trying to make 5v, 1A non Interruptible power supply, To do so i got a Application note from Maxim, but some of the content in that example is totally confusing :confused: to me as i am don't know much about electronics.
There is a part as "SQ433DY" i don't know what exactally it is. So please Help :) me. the parts in the example are not easily avalable in the market also. It is much better if you suggest me some another schemetic for my problem or explain the same.

I have attach the Application Note PDF with this post.
or you can visit at.
5V, Non-Interruptible Power Supply Delivers 1A - Maxim


Last edited:


New Member
I think that may be a misprint. Siliconix MOSFETS usually have an "SI" prefix (for "Siliconix") instead of "SQ". It's a P-channel mosfet with a real low Vgs and Rds(on). This one should work fine -

Digi-Key - SI9433BDY-T1-E3CT-ND (Vishay/Siliconix - SI9433BDY-T1-E3)

It has a gate threshold max of -1.5V and an Rds of .06Ω with just -2.7V on the gate. This corresponds with the text.


New Member
May I please ask a dumb question? What is the make and model of the Ovonics batteries? Is it more than one? If so, are they in parallel or series? Could one add extra batteries to boost the runtime? Thanks for any help. Obviously, you're not not dealing with a high-wattage bulb as far as my circuit expertise is concerned, but this is exactly what I am looking for.

Latest threads

EE World Online Articles