5V boost converter for battery operated projects

5V buck converter

5V buck converter

Today, I finished testing new lightweight boost converter. It is intended as a replacement for my ever-popular 3.3V to 5V converter. The new one is built around Texas Instruments’ TPS61240. It has slightly less output current (rated at 400ma) but is much simpler ( uses just 3 external components ), has several protections built-in, as well as undervoltage lockout (UVLO), which makes this power supply suitable for portable DIY devices.

Take a look at the title picture as well as the datasheet. Here is why I like this controller. First, it has been designed for battery-operated applications – thanks to built-in 2.1V undervoltage lockout it is safe to run this converter from 3 NiMH cells or one LiPo; when battery voltage drops down to UVLO threshold, the converter automatically shuts down. Second, the working frequency of the converter is 3.5MHz, which means that small and inexpensive MLCC inductor can be used. The converter also works well with ceramic capacitors. The total part count is 4 including the IC, and all components are cheap. Lastly, over-temperature and over-voltage protections make this simple supply quite robust.

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