u-blox LEA-5 Series - Pin Description for Antenna Designs (LEA-5 H;5 S;5 A;5 T)

LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
GPS.G5-MS5-09027-A2 Released Design-in
Page 27 of 68
Passive Antenna
Vcc
Micro
Processor
(serial)
1
SDA2
SCL2
TxD1
RxD1
NC/VDDIO
VCC
GND
VCC_OUT
CFG_COM1/MISO
/Reserved
RESET_N
V_BCKP
Reserved
GND
GND
RF_IN
VCC_RF
V_ANT/NC
NC/MOSI/CFG_COM0
NC/SS_N/Reserved
NC/SCK/CFG_GPS0
VDDUSB
USB_DM
USB_DP
EXTINT0
TIMEPULSE
GND
GND
AADET_N/SCS1_N
/Reserved
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LEA-5
Top View
Figure 15: Passive antenna design for LEA-5 receivers not using USB port and not using backup battery
For passive antenna designs use an LNA to increase sensitivity up to 2dB.
2.2.2 Pin description for antenna designs (LEA-5H/5S/5A/5T)
Function
PIN
No
I/O
Description
Remarks
Power
VCC
6
I
Supply Voltage
Provide clean and stable supply.
GND
7, 13-15, 17
I
Ground
Assure a good GND connection to all GND pins of the module,
preferably with a large ground.
VCC_OUT
8
O
Connected to VCC. Leave open if not used.
V_BCKP
11
I
Backup voltage
supply
It‖s recommended to connect a backup battery to V_BCKP in order
to enable Warm and Hot Start features on the receivers. Otherwise
connect to GND (or VCC).
VDDUSB
24
I
USB Power
Supply
To use the USB interface connect this pin to 3.0 – 3.6V derived from
VBUS.
If no USB serial port used connect to GND.
Antenna
RF_IN
16
I
GPS/GALILEO
signal input
from antenna
Use a controlled impedance transmission line of 50 Ohm to connect
to RF_IN.
Don‖t supply DC through this pin. Use V_ANT pin to supply power.
VCC_RF
18
O
Output Voltage
RF section
Can be used to power an external active antenna (VCC_RF
connected to V_ANT with 10R). The max power consumption of
the Antenna must not exceed the datasheet specification of the
module.
Leave open if not used.
V_ANT
19
I
Antenna Bias
voltage
Connect to GND (or leave open) if Passive Antenna is used. If an
active Antenna is used, add a 10R resistor in front of V_ANT input
to the Antenna Bias Voltage or VCC_RF for short circuit protection
use the antenna supervisor circuitry.
AADET_N
20
I
Active Antenna
Detect
Input pin for optional antenna supervisor circuitry. Leave open if not
used.