A possible soldering order for the components of the power system:
- Flying capacitors on the bottom side of the power card: These components are very critical for output to be ripple free and very sensitive to heat. So, try to finish soldering as possible as quickly to avoid even slight differences in the capacitance values.
- TPS60130's: Do not forget to apply grease to the PowerPADs (two rectangles with 9 vias on each) before soldering. PowerPADs are needed to dissipate the heat on the ground plane.
- Input capacitors.
- Output capacitors, tantal and ceramic.
- Voltage divider for low battery input circuit: 680k, 390k and 100nF on the bottom side.
- Low battery indicator led and its resistor.
- Microcontroller and its peripherals.
- JST connector on the sensor board.
- Fuse on the sensor board
- Female header on the sensor board. You may have difficulty while soldering +5V and GND pins due to large power planes!
- Male precision headers. A simple trick: Plug them to the female headers on the sensor board and then plug the power card to the male headers. Solder four pins, unplug the power card and solder rest of them. With this way, alignment problems can be avoided.
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