For this design, follow these general guidelines:
- Place decoupling capacitors close to the associated pins.
- Use ground planes instead of ground traces and minimize the cuts in the ground plane, especially near the AMC131M03. In this design, there is a ground plane on both the top and bottom layer; for this situation, make sure that there is good stitching between the planes through the liberal use of vias.
- Keep the two differential traces to the inputs of an ADC channel symmetrical and as close as possible to each other.
- For the AMC131M03 devices, place the 0.1μF capacitor closer to the AVDD pin than the 1μF capacitor. Do the same thing for the 0.1μF and 1μF capacitors connected to DVDD.
- Minimize the length of the traces used to connect
the crystal to the microcontroller. Place guard rings around the leads of the
crystal and ground the crystal housing. In addition, there must be clean ground
underneath the crystal oscillator (XTAL) or the BAW device, so placing any
traces underneath must be avoided. Also, keep high-frequency signals away from
the clocking island for the MSPM0G3507.
- Use wide traces for power-supply connections.
- Make sure that the recommended clearance and creepage spacing are met for the AMC131M03 and ISOUSB111 isolation devices in this design.