Telit Wireless Solutions SE867-AGPS, Руководство пользователя

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SE867-AGPS User Guide
1VV0300860 Rev. 3 - 2010-05-10
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 25 of 69
Parameter Value Unit
Load capacitance 12.5 pF
Frequency Tolerance

20 ppm
7.4.
dule which can be
in normal mode
n the module is in
867-AGPS internal
1 and 2) RFXEN
be connected to the 1V8_RF_EN ball in order to disable the corresponding
regulator during sleep mode. When using external regulators the enable of the 1V8_RF
RFXEN or RFEN, based on the enable logic (active high or
ce undesired leakage on the RFEN pin we recommend
to RFXEN rather
7.5.
ever it is highly
designed so that the SE867 AGPS can be re-
flashed onboard, in case the need for an update of the module FW should arise during
re required to be
The latest is the
d with a firmware
ring normal mode
module in flash mode.
It’s important to avoid supplying V_IO voltage without supplying 1V8_DIG because
such a power configuration could cause leakage currents and even damages to the
module. At start-up V_IO and 1V8_DIG can be supplied at the same time without
any need of a delay network on the V_IO line (such a network has already been
implemented inside the module), but V_IO can not be supplied before 1V8_DIG. For
the same reasons all the input signals coming to the SE867-AGPS must be driven
low when 1V8_DIG is not present.
RFEN and RFXEN
RFEN and RFXEN are output control signal generated from the mo
used to control power switching. When the module is running
operation the RFXEN signal is set to logic 0 and RFEN to logic 1, whe
sleep RFXEN is logic 1 and RFEN is logic 0. When exploiting the SE
regulators to generate 1V8_DIG and 1V8_RF (power configurations
must
supply must be connected to
active low). In order to redu
using regulators with active low enable logic in order to connect it
than RFEN.
BOOTSEL and flash mode
The SE867-AGPS is supplied flashed and fully functional, how
recommended that the application PCB is
the product lifetime.
In order to correctly perform the flashing procedure 4 signals a
externally controlled: TX_UART, RX_UART, Reset and BOOTSEL.
control signal used to put the module in flash mode and procee
flashing. The signal has an internal pull-up and can be left floating du
functioning, driving it low puts the