12 Application Reference Design

This section shows the ATSAMR30M18A module application schematics for different supported host interfaces. It is required to add 100Ω series resistors for module pins 3, 4, 6, 17, 19 and 20 to minimize radiated emission from the open-ended connectors/traces. Place these resistors (R101, R102, R103, R104, R105 and R106) as close as possible to the specific module pin in the PCB layout. If any of these module pins (3, 4, 6, 17, 19 and 20) are left unused in the design, it is recommended these pins be terminated through a 10 kΩ resistor to GND. Additionally, drive the pins to logic low during the firmware initialization.