Integration Manual

Table Of Contents
LISA-U series - System Integration Manual
3G.G2-HW-10002-A3 Preliminary System description
Page 73 of 160
“GPS data ready” and “GPS RTC sharing” functions are not supported by all u-blox GPS receivers HW or
ROM/FW versions. Refer to the GPS Implementation Application Note [16] or to the Hardware
Integration Manual of the u-blox GPS receivers for the supported features.
Functions not supported by LISA-Uxxx-00 versions
LISA-U series
R1
INOUT
GND
GPS LDO
Regulator
SHDN
u-blox
1.8 V GPS receiver
SDA2
SCL2
R2
1V8 1V8
VMAIN1V8
U1
21
GPIO2
SDA
SCL
C1
TxD1
EXTINT0
GPIO3
GPIO4
46
45
23
24
VCC
R3
V_BCKP V_BCKP
2
Functions not supported by LISA-U200-00 version
Figure 40: DDC Application circuit for u-blox 1.8 V GPS receiver
Reference
Description
Part Number - Manufacturer
R1, R2
4.7 k Resistor 0402 5% 0.1 W
RC0402JR-074K7L - Yageo Phycomp
R3
47 k Resistor 0402 5% 0.1 W
RC0402JR-0747KL - Yageo Phycomp
U1
Voltage Regulator for GPS Receiver
See GPS Receiver Hardware Integration Manual
Table 32: Components for DDC application circuit for u-blox 1.8 V GPS receiver
The application circuit for the connection of a LISA-U series wireless module to a u-blox 3.0 V GPS receiver is
illustrated in Figure 41.
If a u-blox 3 V GPS receiver is used, the SDA, SCL, GPIO3 and GPIO4 pins of the LISA-U series wireless module
cannot be directly connected to the u-blox 3 V GPS 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 wireless module can be directly connected to the
V_BCKP backup supply input pin of the GPS receiver as in the application circuit for a u-blox 1.8 V GPS receiver.