EVA-8M and EVA-M8 series - Hardware Integration Manual
UBX-16010593 - R06
Design-in
Page 20 of 47
Early Production Information
31
TIMEPULSE
O
Time pulse output
Leave open if not used.
32
D_SEL
I
Interface selector
See section 2.2.
33
SAFEBOOT_N
I
Used for programming the SQI flash
memory and testing purposes.
Leave open if not used.
34
ANT_OK
I
Antenna status
Leave open if not used.
35
ANT_OFF
O
Antenna control
Leave open if not used.
36
Reserved
I/O
Reserved
Do not connect. Must be left open!
37
GND
I
Ground
Inner ground pin
38
GND
I
Ground
Inner ground pin
39
GND
I
Ground
Inner ground pin
40
GND
I
Ground
Inner ground pin
41
GND
I
Ground
Inner ground pin
42
GND
I
Ground
Inner ground pin
43
GND
I
Ground
Inner ground pin
Table 5: EVA-8M / EVA-M8 series GNSS modules pin description
2.9.1
Pin name changes
Selected EVA-M8M pin names have been updated to agree with a common naming convention across
u-blox modules. The pins have not changed their operation and are the same physical hardware but
with updated names. The table below lists those pins along with their old and new names.
No
Previous Name
New name
7
V_USB
VDD_USB
15
RX / MOSI
RXD / SPI MOSI
16
TX / MISO
TXD / SPI MISO
26
SQI_CS
SQI_CS_N
29
SCL / SCK
SCL / SPI CLK
30
SDA / CS_N
SDA / SPI CS_N
Table 6: EVA-M8M pin name changes
☞
For more information about pin assignment see the
EVA-M8 Data Sheet [1] and the EVA-8M Data
Sheet [2]
2.10
Layout design-in checklist
Follow this checklist for the layout design to get an optimal GNSS performance.
Layout optimizations (Section 2.11)
Is the EVA-8M / EVA-M8 module placed according to the recommendation in section 2.11.3?
Is the grounding concept optimal?
Has the 50
Ω
line from antenna to module (micro strip / coplanar waveguide) been kept as short
as possible?
Assure low serial resistance in
VCC
power supply line (choose a line width > 400 um).
Keep power supply line as short as possible.
Design a GND guard ring around the optional RTC crystal lines and GND below the RTC circuit.
Add a ground plane underneath the GNSS module to reduce interference. This is especially
important for the RF input line.
For improved shielding, add as many vias as possible around the micro strip/coplanar waveguide,
around the serial communication lines, underneath the GNSS module, etc.
