VUE32_SUPPLIES

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Power supplies

General comments:

• We use a switch-mode power supply (DC/DC) to convert 12V in 5V
• The TPS2111 allows the board to be powered from USB or from +12V.
  • +12V has the priority
  • See below
• It's possible to remove IC10 and fix the supply source with RU5 and RU6 (cheaper, less practical option)

Known issue:

The power hot swap doesn't work. There is a mistake on the usage of the TPS2111A. With the current configuration, the main supply has to drop below 0.8V before the chip picks the second input. At this voltage, the MCU resets. We need two resistors to fix this. Please refer to the datasheet, figure 14 http://www.ti.com/lit/ds/symlink/tps2111.pdf....

Even with that mistake, you can power the board safely from +12V and/or from USB. The only problem is that you get a reset if you unplug one of the sources.