NEO-D9S - Integration manual
Pin no.
Name
I/O
Description
14
ANT_OFF
O
External LNA disable - default active high
15
ANT_DETECT
I
Active antenna detect - default active high
16
ANT_SHORT_N
O
Active antenna short detect- default active low
17
EXTINT
I
External interrupt pin
18
SDA / SPI CS_N
I/O
I2C data if D_SEL = VCC (or open); SPI chip select if D_SEL = GND
19
SCL / SPI SLK
I/O
I2C clock if D_SEL = VCC (or open); SPI clock if D_SEL = GND
20
TXD / SPI MISO
O
UART1 output if D_SEL = VCC (or open); SPI MISO if D_SEL = GND
21
RXD / SPI MOSI
I
UART1 input if D_SEL = VCC (or open); SPI MOSI if D_SEL = GND
22
V_BCKP
I
Connect to VCC or leave it open
23
VCC
I
Supply voltage
24
GND
I
Ground
Table 6: NEO-D9S pin assignment
4.2 Antenna
An active antenna is mandatory with the NEO-D9S. The NEO-D9S needs to receive L-band signals
in order to operate.
A separate L-band antenna should be used to meet the requirement of +4 dBic patch
element gain.
A suitable ground plane is required for the antenna to achieve good performance for the L-
band antenna.
Location of the antenna is critical for reaching good performance.
Figure 13: Typical L-band active antenna structure
UBX-19026111 - R07
4 Design
Page 24 of 52
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