LEA-M8S / LEA-M8T - Hardware integration manual
UBX-15030060 - R06 Design Page 11 of 33
Production information
2 Design
2.1 Pin description
Provide clean and stable supply.
Assure a good GND connection to all GND pins of
the module.
It is recommended to connect a backup supply
voltage to V_BCKP in order to enable warm and
hot start features on the positioning modules.
Otherwise, connect to VCC.
To use the USB interface connect this pin to 3.0 –
3.6 V.
If no USB serial port used connect to GND.
GNSS signal input from
antenna
Use a controlled impedance transmission line of
50 to connect to RF_IN.
Output voltage RF
section
Can be used to power external LNA or an external
active antenna (VCC_RF connected to V_ANT
with 10 ). The max power consumption of the
antenna must not exceed the data sheet
specification of the module. Leave open if not
used.
Connect to GND (or leave open) if passive antenna
is used. If an active antenna is used, add a 10
resistor in front of V_ANT input to the antenna
bias voltage or VCC_RF.
Ext. interrupt pin. Int. pull-up resistor to VCC. Can
be configured as open circuit detection
(ANT_DET_N). Leave open if not used.
TXD 3
(LEA-M8S)
TXD / SPI MISO
(LEA-M8T)
Serial port TXD if D_SEL =1 (or open)
SPI MISO if D_SEL = 0
RXD 4
(LEA-M8S)
RXD / SPI MOSI
(LEA-M8T)
Serial port if RXD D_SEL =1 (or open)
SPI MOSI if D_SEL = 0
USB2.0 bidirectional communication pin. Leave
open if unused. For implementations, see section
1.4.
Hardware Reset
(Active Low)
Leave open if not used. Do not drive high.
Configurable timepulse 1 signal (one pulse per
second by default). Leave open if not used.
TP2/SAFEBOOT_
N
(LEA-M8T)
SAFEBOOT_N
(LEA-M8S)
Configurable timepulse signal. Must not be held
LO during start-up.
Must not be held LO during start-up.
Ext. interrupt pin. Int. pull-up resistor to VCC.
Leave open if unused. The pin can also be used as
a generic PIO (PIO13).