Smart Machine Smart Decision
SIM5360_Hardware Design_V1.01
2013-11-22
48
Figure 35
:
Passive antenna circuit (Default)
In above figures, the components C1 and L1, L2 are used for antenna matching, the values of the
components can only be obtained after the antenna tuning usually, and they are provided by antenna
vendor.C2 in Figure 36 is used for DC isolation. In active antenna circuit, users must use an external
LDO/DCDC to provide VDD voltage whose value should be taken according active antenna characteristic,
and VDD can be shut down to avoid consuming additional current when not being used.
GPS can be used by NMEA port. User can select NMEA as output through UART or USB. NMEA
sentences are automatic and no command is provided. NMEA sentences include GSV, GGA, RMC, GSA,
and VTG. Before using GPS, user should configure SIM5360 in proper operating mode by AT command.
Please refer to related document for details. SIM5360 can also get position location information through
AT directly.
Note:GPS is closed by default, it could be started by AT+CGPS. The AT command has two parameters, the first is on/off,
and the second is GPS mode. Default mode is standalone mode.
AGPS mode needs more support from the mobile telecommunication network. Refer to AGPS application document for
details.
3.13
Multi-functional interface
SIM5360 merges functions for various applications. It can enrich users’ design and lower the cost of users’
hardware.
3.13.1
Sink Current Source
The dedicated pin (CURRENT_SINK) is intended for driving passive devices
,
such as LCD backlight, this
implementation is VBAT tolerant and suitable for driving white LEDs. The high-current driver can
maintain a constant current which is set by
the AT command “AT+ CLEDITST”
, capable of up to 40 mA.