Working on my pet project (a Cortex M7 breakout board, like a Teensy on steroids, but with proper debugging features and a fast double-precision FPU) I thought: “Wouldn’t it be nice to have a PSU on board that is pre-made, very compact and easily swappable to reconfigure the board?”
After good dose of NIH and some frantic KiCad puzzling: My first attempt to create a standard device and footprint. I’d love to hear your thoughts, feedback (requests?).
The idea is to publish it as open hardware (no insane OSHWA certification, probably CC-BY-SA or something similarly relaxed) once the prototypes work well.
Generic requirements for the module:
- Cold swappable
- Tiny footprint area (26x10mm, parts underneath possible)
- Able to use technology that is applicable to integrated designs
- Optional MCU interface (I2C)
The module I designed first is a more advanced one, simply because that’s the one I want to use:
- 3 to 17 VDC input
- 1.5 to 12 VDC output
- 3.5 A
- MCU en/disable
- MCU controllable output voltage
- Voltage and current monitoring
The pin headers are the 2mm type (instead of the 2.54mm defaults). I like to this as a way to make sure I won’t accidentally use them as GPIO. The headers and sockets are common enough.
The additional input Vin & GND pins can be left unconnected by either the host or module.
The two three pad areas in the top right corner are address selectors for both I2C chips (you can use up to four modules per I2C bus).
Future versions I’d like to add
- Cheap and simple fixed output
- Dual voltage modules (both output pins are joined in the current design, but can be used separately)
- Battery backed / charging
- MPPT solar input
Front copper layer
Back copper layer
I’d love to hear your critiques, suggestions or requests.