Integration Manual

JODY-W3 series - System integration manual
UBX-19011209 - R07 Design-in Page 27 of 71
C2-Restricted
• It is highly recommended to strictly follow the specific guidelines provided by the antenna
manufacturer regarding correct installation and deployment of the antenna system, including
PCB layout and matching circuitry.
• Further to the custom PCB and product restrictions, antennas may require tuning/matching to
reach the target performance. It is recommended to plan measurement and validation activities
with the antenna manufacturer before releasing the end-product to manufacturing.
• The receiver section may be affected by noise sources like hi-speed digital busses. Avoid placing
the antenna close to busses as DDR or consider taking specific countermeasures like metal
shields or ferrite sheets to reduce the interference.
• Take care of interaction between co-located RF systems like LTE sidebands on 2.4 GHz band.
Transmitted power may interact or disturb the performance of JODY-W3 modules where specific
LTE filter is not present.
2.3 Supply interfaces
2.3.1 Module supply design
Though the GND pins are internally connected, it is recommended to connect all the available ground
pins to solid ground on the application board as a good (low impedance) connection to external ground
can minimize power loss and improve RF and thermal performance. JODY-W3 modules must be
sourced through 3V3, 1V8 and VIO pins with proper DC power supplies that comply with the voltage
supply requirements summarized in Table 4.
Good connection of the JODY-W3 series module power supply pins with DC supply source is required
for accurate RF performance and schematic guidelines are summarized below:
• All power supply pins must be connected to an appropriate DC source.
• Any series component with Equivalent Series Resistance (ESR) greater than a few mΩ should be
avoided. Only exceptions to this rule are ferrite beads used for DC filtering, however those parts
should be used carefully to avoid instability of the DC/DC supply powering the module and are in
general not required.
• A minimum bulk capacitance of 10 µF on the 3V3 rail is required (optionally on 1V8 and VIO) close
to the module to help filter current spikes from the RF section and avoid ground bounce. The
preferred choice is a ceramic capacitor with X7R or X5R dielectric due to low ESR/ESL. Special care
should be taken in the selection of X5R/X7R dielectrics due to capacitance derating vs DC bias
voltage.
• Additional bypass capacitors in the range of 100 nF to 1 µF on all supply pins are required for high
frequency filtering. The preferred choice is a ceramic capacitor with X7R or X5R dielectric due to
low ESR/ESL. Smaller size bypass capacitors should be chosen for the manufacturing process to
minimize ESL. This capacitor should be placed as close as possible to the module supply pin.
2.3.1.1 Guidelines for VCC supply circuit design using a switching regulator
It is recommended to use a Switched Mode Power Supply (SMPS) when the difference from the
available supply rail to the JODY-W3 supply rails allows significant power savings. For example,
conversion of a 12 V or greater voltage supply to the nominal 3.3 V value for the 3V3 supply.
The characteristics of the SMPS connected to the 3V3 pin should meet the following prerequisites to
comply with the module requirements summarized in Table 4.
• Power capability: The switching regulator together with any additional filter in front of the module
must be capable of providing a voltage within the specified operating range. The regulator must
also be capable of delivering the specified peak current.