Cinterion EES3, Hardware Interface Description

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EES3 Hardware Interface Description
3.3 Power Up / Power Down Scenarios
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EES3_HD_v01.100b Page 30 of 118 2009-08-12
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3.3.1.2 Configuring the IGT Line for Use as ON/OFF Switch
The IGT line can be configured for use in two different switching modes: You can set the IGT
line to switch on the module only, or to switch it on and off. The switching mode is determined
by the parameter "MEShutdown/OnIgnition" of the AT^SCFG command. This approach is use-
ful for application manufacturers who wish to have an ON/OFF switch installed on the host de-
vice.
By factory default, the ON/OFF switch mode of IGT is disabled:
To configure IGT for use as ON/OFF switch:
We strongly recommend taking great care before changing the switching mode of the IGT line.
To ensure that the IGT line works properly as ON/OFF switch it is of vital importance that the
following conditions are met.
Switch-on condition:If the EES3 is off, the IGT line must be asserted for at least 400ms before
being released. The module switches on after 400ms.
Switch-off condition:If the EES3 is on, the IGT line must be asserted for at least 1s before being
released. The module switches off after the line is released. The switch-
off routine is identical with the procedure initiated by AT^SMSO, i.e. the
software performs an orderly shutdown as described in
Section 3.3.3.1 .
Before switching off the module wait at least 2 seconds after startup.
Figure 7:
Timing of IGT if used as ON/OFF switch
3.3.1.3 Turn on EES3 Using the VCHARGE Signal
As detailed in Section 3.5.7 , the charging adapter can be connected regardless of the module’s
operating mode.
If the charger is connected to the charger input of the external charging circuit and the module’s
VCHARGE line while EES3 is off, and the battery voltage is above the undervoltage lockout
threshold, processor controlled fast charging starts (see
Section 3.5.6 ). EES3 enters a restrict-
ed mode, referred to as Charge-only mode where only the charging algorithm will be launched.
at^scfg=meshutdown/onignition
^SCFG: "MEShutdown/OnIgnition","off"
OK
# Query the current status of IGT.
# IGT can be used only to switch on EES3.
IGT works as described in Section 3.3.1.1 .
at^scfg=meshutdown/onignition,on
^SCFG: "MEShutdown/OnIgnition","on"
OK
# Enable the ON/OFF switch mode of IGT.
# IGT can be used to switch on and off EES3.