LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 59 of 125
The pin must be connected to the active-high enable pin (or the active-low shutdown pin) of the voltage
regulator that supplies the u-blox GPS receiver on the application board.
The “GPS supply enable” function improves the power consumption of the GPS receiver. When GPS
functionality is not required, the wireless module controlled by the application processor can completely switch
off the GPS receiver using AT commands.
The application circuit for connecting LEON-Gx00-04S and LEON-Gx00-05S versions to a u-blox 3.0 V GPS
receiver is illustrated in Figure 35, and the suggested components are listed in Table 20. A pull-down resistor is
mounted on the
GPIO2
line to avoid a switch-on of the GPS receiver when the wireless module is switched-off
and its digital pins are tri-stated.
The
V_BCKP
supply output of the LEON-G100 / LEON-G200 series wireless module is connected to the
V_BCKP
backup supply input pin of the GPS receiver to provide the supply for the GPS real time clock and backup RAM
when the
VCC
supply of the wireless module is within its operating range and the
VCC
supply of the GPS
receiver is disabled. This enables the u-blox GPS receiver to recover from a power outage with either a hot start
or a warm start (depending on the duration of the GPS
VCC
outage) and to maintain the configuration settings
saved in the backup RAM.
LEON-Gx00-04S
LEON-Gx00-05S
R1
IN
OUT
GND
GPS LDO
Regulator
SHDN
u-blox
3.0 V GPS receiver
SDA2
SCL2
R2
3V0
3V0
VMAIN
3V0
U1
21
GPIO2
SDA
SCL
C1
31
30
VCC
R3
2
V_BCKP
V_BCKP
Figure 35: Application circuit for LEON-Gx00-04S and LEON-Gx00-05S versions and u-blox 3.0 V GPS receivers
Reference
Description
Part Number - Manufacturer
R1, R2
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 GPS Receiver
See GPS Receiver Hardware Integration Manual
Table 20: Component for application circuit for LEON-Gx00-04S and LEON-Gx00-05S versions and u-blox 3.0 V GPS receivers
Comment [tgri1]:
This paragraph is
repeated in the previous description
(LEON-Gx00-06 and subsequent
versions). Would it be possible to
restructure or add a cross reference to
prevent the repetition?