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ut-robotics / picr22-team-kivipallur-jurto

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Improve switching regulator layout #48

Closed ReikoR closed 1 year ago

ReikoR commented 1 year ago

image

Try to follow 12.1 Layout Guidelines in TPS62933 datasheet.

See also: https://github.com/ut-robotics/picr22-team-owo/issues/41 https://github.com/ut-robotics/picr22-team-saga/issues/26

ReikoR commented 1 year ago

From datasheet, section 12.1 Layout Guidelines:

Place the inductor, input and output capacitors, and the IC on the same layer. Place the input and output capacitors as close as possible to the IC. The VIN and GND traces must be as wide as possible and provide sufficient vias on them to minimize trace impedance. The wide areas are also of advantage from the view point of heat dissipation.

Input and output capacitors are not on the same layer: image

GND and VIN traces are not as wide as possible: image

Place a 0.1-µF ceramic decoupling capacitor or capacitors as close as possible to VIN and GND pins, which is key to EMI reduction.

image

Keep the SW trace as physically short and wide as practical to minimize radiated emissions.

Not short and wide as possible. Inductor should be placed near SW pin. image

ReikoR commented 1 year ago

  1. +5V feedback trace should not be routed in a big loop. In current layout it's probably better to just connect it straight from capacitors to feedback resistors on the top layer. image

  2. It would be better to connect ground with multiple vias. Moving the mounting hole would help to place input capacitors closer to the regulator. \ Current layout: image \ Proposed layout: image

  3. At the output it would be better to connect 5V capacitors with a polygon. Currently 0.1uF capacitor is connected with feedback trace. \ Current layout: image \ Proposed layout: image image