Quite a while ago I built a USB adapter for my Zipit based on the Texas Instruments TPS61240 boost converter IC. It’s a small chip and only needs 3 external components to function. The ouput current is limited to 400-450mA but it runs most low power USB devices just fine (flash drive, mouse, webcam). It also has a wide input voltage range of 2.3V-5.5V. This makes it a great boost converter for low power / battery operated projects so I decided to design a breakout board for it.
This is the first board I’ve received from OSHPark. Purple must be the new black. The OSHPark website is purple, the boards were shipped in a purple package and the boards themselves are purple. I must admit, purple circuit boards look pretty cool :)
The enable pin (pull high enable, low disable) is broke out to both the input and output side. This allows you to turn the regulator on or off from a microcontroller. The ENJMP pads are tied to the input voltage. Soldering these pads together (or 0 ohm resistor) connects VIN to ENABLE and keeps the regulator on all the time. I had a small batch of boards made and sell them in my Tindie Store. The boards in my store come with a 0 ohm resistor soldered on the ENJMP pads. If you want to control the regulator with a microcontroller using the EN pins, use a hot soldering iron to remove the resistor.
The TPS61240 is the same chip used in the Zipit Z2 Breakout board.