LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
GPS.G5-MS5-09027-A2
Released
Design-in
Page 32 of 68
Function
PIN
No
I/O Description
Remarks
Power
VCC
1
I
Supply Voltage
Provide clean and stable supply. Maximum allowed Ripple
Vcc=50mV.
GND
2,11-16,18
I
Ground
Assure a good
GND
connection to all
GND
pins of the module,
preferably with a large ground plane.
VCC_OUT
10
O
Connected to
VCC
. Leave open if not used.
V_BCKP
21
I
Backup voltage
supply
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
).
Antenna
RF_IN
17
I
GNSS 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
20
O
Output Voltage
RF section
Can be used to power an external active antenna (
VCC_RF
connected to
V_ANT
). 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 for short circuit protection or use the antenna supervisor
circuitry.
AADET_N
27
I
Active Antenna
Detect
Input pin for optional antenna supervisor circuitry.
Leave open if not used.
UART
TxD1
5
O
Serial Port 1
Serial port output. Leave open if not used.
TxD2
6
O
Serial Port 2
3.6V tolerant serial input. Internal pull-up resistor to VCC. Leave
open if not used.
RxD1
4
I
Serial Port 1
Serial port input with internal pull-up resistor to VCC. Leave open if
not used.
Note
Don‖t use an external pull up resistor.
RxD2
7
I
Serial Port 2
System
RESET_N
22
I
Hardware Reset
(Active Low)
Leave open if not used. Do not drive high.
TIMEPULSE
29
O
Timepulse
Signal
Configurable Timepulse signal (one pulse per second by default).
Leave open if not used.
EXTINT0
23
I
External
Interrupt
External Interrupt Pin.
Internal pull-up resistor to
VCC
. Leave open if not used.
Table 7: Pinout TIM-5H
2.5
Layout
This section provides important information for designing a reliable and sensitive GPS system.
GPS signals at the surface of the Earth are about 15dB Below the thermal noise floor. Signal loss at the antenna
and the RF connection must be minimized as much as possible. When defining a GPS receiver layout, the
placement of the antenna with respect to the receiver, as well as grounding, shielding and jamming from other
digital devices are crucial issues and need to be considered very carefully.
2.5.1
Footprint and paste mask
Figure 18 through Figure 23 describe the footprint and provide recommendations for the paste mask for LEA-5,
NEO-5 and TIM-5H modules. These are recommendations only and not specifications. Note that the Copper and
Solder masks have the same size and position.
To improve the wetting of the half vias, reduce the amount of solder paste under the module and increase the
volume outside of the module by defining the dimensions of the paste mask to form a T-shape (or equivalent)
extending beyond the Copper mask. The solder paste should have a total thickness of 170 to 200 m.
