Switch Mode Step up DC-DC converter

Thread Starter


Joined Dec 10, 2011
Hi all,

I have a problem with the choice of parts for my new summer project. I am making a lithium powered USB mobile power supply with an arduino to monitor charge/discharge rates, temperature and simple stuff like switching off when battery is discharged to 2.7V. I will probably etch my own PCB as well.

However, the main problem i face now is that i cant find a reasonable SMPS that will fulfil my requirements.

1. Can supply 5V 2A from 2.7V to 4.2V (Using lithium cells to charge my iPad)
2. Affordable <15USD incl shipping to Singapore
3. DIP / TO-220 package or something that can be easily soldered
4. Efficiency above 85% at 2A output

I have checked out linear, maxim and national semicond... but so far no satisfactory find. Here are some of the chips that i was seriously considering..

LT1370 - 13USD but I can only find DD Pak package which i am unsure how to solder.

MAX669 - uMax package which is extremely small to solder and requires quite a number of external components

MAX1709 - Shipping to Singapore seems extremely expensive.

Any ideas? Or anyone with spare ICs?

Thanks in advance.