Ublox LEA-M8S, Hardware Integration Manual

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LEA-M8S / LEA-M8T - Hardware integration manual
UBX-15030060 - R06 Design Page 11 of 33
Production information
2 Design
2.1 Pin description
Function Pin No. I/O Description Remarks
Power VCC 6 I Supply voltage Provide clean and stable supply.
GND 7, 13, 14,
15, 17 - Ground Assure a good GND connection to all GND pins of
the module.
VCC_OUT 8 O Output voltage (VCC) Leave open if not used.
V_BCKP 11 I Backup supply voltage 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.
VDD_USB 24 I USB power supply
To use the USB interface connect this pin to 3.0 –
3.6 V.
If no USB serial port used connect to GND.
Antenna RF_IN 16 I GNSS signal input from
antenna Use a controlled impedance transmission line of
50
 to connect to RF_IN.
VCC_RF 18 O 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.
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 10

resistor in front of V_ANT input to the antenna
bias voltage or VCC_RF.
EXTINT1 20 I Ext. interrupt Ext. interrupt pin. Int. pull-up resistor to VCC. Can
be configured as open circuit detection
(ANT_DET_N). Leave open if not used.
UART TXD 3
(LEA-M8S)
TXD / SPI MISO
(LEA-M8T) O TXD
Serial port TXD
O TXD
SPI MISO Serial port TXD if D_SEL =1 (or open)
SPI MISO if D_SEL = 0
RXD 4
(LEA-M8S)
RXD / SPI MOSI
(LEA-M8T) I RXD
Serial port if RXD
I RXD
SPI MOSI Serial port if RXD D_SEL =1 (or open)
SPI MOSI if D_SEL = 0
USB USB_DM 25 I/O USB I/O line USB2.0 bidirectional communication pin. Leave
open if unused. For implementations, see section
1.4.
USB_DP 26 I/O USB I/O line
System RESET_N 10 I Hardware Reset
(Active Low) Leave open if not used. Do not drive high.
TIMEPULSE 28 O Timepulse 1 Configurable timepulse 1 signal (one pulse per
second by default). Leave open if not used.
TP2/SAFEBOOT_
N
(LEA-M8T)
SAFEBOOT_N
(LEA-M8S) 12 I/O Safeboot_N / Timepulse
2
Configurable timepulse signal. Must not be held
LO during start-up.
I/O Safeboot_N Must not be held LO during start-up.
EXTINT0 / PIO13 27 I /
(O) Ext. interrupt / PIO13 Ext. interrupt pin. Int. pull-up resistor to VCC.
Leave open if unused. The pin can also be used as
a generic PIO (PIO13).