LISA-C2 series and FW75-C200 - System Integration Manual
UBX-13000620 - R21
Early Production Information
System description
Page 37 of 103
LISA-C200 does NOT have V_BCKP output to power the GNSS receiver RTC. Either V_INT or
independent LDO can be used to source the RTC. V_INT output is 1.8 VDC after the module is
fully powered on. See the
LISA-C2 series Data Sheet [1]
u-blox
Wireless Module
(except LISA-C200)
R1
IN
OUT
GND
GPS LDO
Regulator
SHDN
u-blox GPS / GNSS
1.8 V receiver
SDA2
SCL2
R2
1V8
1V8
VMAIN
1V8
U1
21
GPIO2
SDA
SCL
C1
TxD1
EXTINT0
GPIO3
GPIO4
46
45
23
24
VCC
R3
V_BCKP
V_BCKP / RSVD
2
R4
Figure 19: DDC Application circuit for u-blox GNSS 1.8 V receiver
Reference
Description
Part Number - Manufacturer
R1, R2, R4
4.7 k
Ω
Resistor 0402 5% 0.1 W
RC0402JR-074K7L - Yageo Phycomp
R3
47 k
Ω
Resistor 0402 5% 0.1 W
RC0402JR-0747KL - Yageo Phycomp
U1
Voltage Regulator for GNSS Receiver
See GNSS Receiver Hardware Integration Manual
Table 18: Components for DDC application circuit for u-blox GNSS 1.8 V receiver
Figure 20 illustrates the application circuit for the connection of a LISA-C cellular module to a u-blox GNSS 3.0 V
receiver.
If a u-blox GNSS 3.0 V receiver is used, the
SDA
,
SCL
,
GPIO3
and
GPIO4
pins of the LISA-C cellular module
cannot be directly connected to the u-blox GNSS 3.0 V receiver: a proper I
2
C-bus Bidirectional Voltage Translator
must be used for the
SDA
and
SCL
signals, and a general purpose Voltage Translator must be used for the
GPIO3
and
GPIO4
signals. The
V_BCKP
supply output of the cellular module can be directly connected to the
V_BCKP
backup supply input pin of the GNSS receiver as in the application circuit for a u-blox GNSS 1.8 V
receiver.