ATX Breakout Board
Eagle files for my ATX Breakout Board (v1, with USB support using a TPS2513 and voltage control with a LM317). Based on the Dangerous Prototypes' idea.
New version (v1.2)
Just finished updating the board. BOM updates and post blogs will follow. I'm also printing a second batch (20-30 PCBs) soon.
Changes and additions:
- Thickened many traces, removed pin headers in the middle of the board and added one behind each binding post (up to 5 output pins per voltage line, with no risk of burning any traces).
- Added resistors to the USB ports (on the back of the board). You may want to use them for USB identification, as they are cheaper and easier to find than the TPS2513. Adafruit link for more info: https://learn.adafruit.com/minty-boost/icharging
- Moved LM317 so that you can mount it horizontally + used a footprint with longpads, should you want to solder wires to an external voltage reg + heatsink.
- Prototyping area added at the top left of the board. Not sure if it will ever come useful, but I had some empty space there. You have easy access to the 3V3 and 5V lines.
- Moved/rearranged several parts (pot, switch, LEDs) in order to draw shorter and cleaner traces.
- 24-pin ATX connector.
- Voltage lines are all broken out individually on binding posts.
- LM317-based voltage regulator. Using a 300 ohm resistor and a 2K ohm potentiometer, voltage range is 1.25-9V.
- **2 USB ports **based on the TPS2513 from Texas Instruments. They can automatically detect what device is connected and adjust resistance on D+ and D- lines as needed. This means full compatibility and maximum charging speed on both Apple and Android devices. One of them is connected to 5v_STDBY, so that it works even when the PSU is off.
- Pretty much everything can be fused. I left -12V out because it can only carry low amounts of current on most PSUs (mine is 500mA maximum).
- Breadboard pin headers so that voltage lines can be connected to a breadboard using jumper cables.
- Voltmeter headers in order to know the LM317 output voltage.
- There is room for a 9W power resistor is your PSU needs it to stabilize output voltages. You can connect it either to the 5v rail or to the 12v one by jumpering the corresponding pads.
- Status LEDs on fused lines and USBs so you can check if everything works fine.
- Screw holes for standoffs.
More details and pictures on my blog: http://b.truzzi.me/building-a-better-breakout-board-for-atx-psus-2
Suggestions and feedback are very welcome!