4.4 WBZ45 Module Routing Guidelines

  • Use the multi-layer host board for routing signals on the inner layer and the bottom layer.
  • The top layer (underneath the module) of the host board must be ground with as many GND vias as possible, (see the following figure).
  • Avoid fan-out of the signals under the module or antenna area. Use a via to fan-out signals to the edge of the WBZ45 Module.
  • For a better GND connection to the WBZ45 Module, solder the exposed GND pads of the WBZ45 Module on the host board.
  • For the module GND pad, use a GND via of a minimum 10 mil (hole diameter) for good ground to all the layers and thermal conduction path.
  • The recommendation is to have a series resistor on the host board for all GPIOs. Place these resistors close to the WBZ45 Module. The following figure illustrates the placement of the series resistor.
Figure 4-12. Example of Host Board on Top Layer