Using an amazingly small little boost converter to make a 5V regulated power pack from a couple of AAA batteries.
I picked up some 5V DC-DC Step-Up Power Modules on aliexpress for a nice price (SG$1.62 for 5), following a suggestion from @steveschnepp for making a 5V power pack from AA or AAA batteries.
These are tiny! They are built on a 10.4mm x 10.4mm PCB, gross component height 7.5mm. There are 3 connections (Vin, Vout and Ground), which can take standard 2.54mm pin headers if desired (not supplied).
These modules are built around the Micro One ME2108 step-up DC/DC converter from Nanjing Micro One Electronics Inc. 版权所有.南京微盟电子有限公司.
Specifically, it uses the ME2108A/50 SOT-89-3 packaging with 5.0V output and an operating input range of 0.9V~6.5V.
| PIN | NAME | FUNCTION |
|---|---|---|
| 1 | Vss | Ground |
| 2 | Vout | Output voltage monitor, IC internal power supply |
| 3 | Lx | Switch |
The module just implements the standard circuit using internal transistor as described in the datasheet:
Components:
- ME2108A/50 step-up DC/DC converter
- 220µH inductor
- SS14 - 1N5820 Small Signal Schottky Diode
- 5µF + 3µF capacitors? I haven't measured the values
It works just fine with 2x AAA batteries. Here's a quick test on a breadboard:
As the ME2108 has an input range of 0.9V~6.5V, it also works with a single AAA battery, though the output regulation is down a little:
I've just added a switch and mounted on to a 2xAAA battery pack with globs of hot glue (for insulation as much as structural strength).
And now I have a little 5V power source powered by AAA batteries:
I really like this idea, especially for powering little embedded projects that need 5V: the smaller, cheaper and easier option than a rechargeable 18650 power pack.
- 0.9-5V To 5V DC-DC Step-Up Power Module Voltage Boost Converter Board 1.5V 1.8V 2.5V 3V 3.3V 3.7V 4.2V To 5V - aliexpress
- Nanjing Micro One NB: currently served with an expired and invalid SSL certificate