PAM-7Q - Hardware Integration Manual
UBX-13003143 - R06
Early Production Information
Design
Page 10 of 26
3
Design
3.1
Design checklist
Designing-in a PAM-7Q module is easy, especially when based on a u-blox reference design. This section lists the
most important items for a simple design check. The design checklist can also help to avoid an unnecessary PCB
respin and achieve the best possible performance. Follow the design checklists when developing PAM-7Q GPS
applications. This can significantly reduce development time and costs.
3.1.1
Schematic checklist
Power supply requirements
GNSS positioning modules require a stable power supply. In selecting a strategy to achieve a clean and
stable power supply, any resistance in the VCC supply line can negatively influence performance.
Consider the following points:
o
Wide power lines or even power planes are preferred.
o
Avoid resistive components in the power line (e.g. narrow power lines, coils, resistors, etc.).
o
Placing a filter or other source of resistance at VCC can create significantly longer acquisition
times.
Is the power supply (VCC) within the specified range? (see the
PAM-7Q Data Sheet
Compare the peak supply current consumption of your PAM-7Q module
with the specification of the
power supply. (See the
PAM-7Q Data Sheet
for more information.)
At the module input, use low ESR capacitors that can deliver the required current/charge for switching
from backup mode to normal operation.
Backup battery
Use of valid time and the GNSS orbit data at startup will improve the GNSS performance i.e. enables hot
starts, warm starts and the AssistNow Autonomous process as well as AssistNow Offline. To make use of
these features connect a battery to V_BCKP to continue supplying the backup domain in case of power
failure at VCC.
If no backup supply voltage is available, connect the
V_BCKP
pin to
VCC
).
