Siemens TC65 - Turn on TC65 Using the VCHARGE Signal; Figure 6: Power-On with IGT Held Low before Switching on Operating Voltage at BATT

TC65 Hardware Interface Description
Strictly confidential / Draft
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TC65_HD_V00.521 Page 28 of 99 24.05.2005
EMERG_RST
PWR_IND
t = 400ms
min
120ms
BATT+
IGT
HiZ
VEXT
TXD0/TXD1/RTS0/RST1/DTR0 (driven by the application)
CTS0/CTS1/DSR0/DCD0
ca. 500 ms
Serial interfaces
ASC0 and ASC1
Undefined
Active
Figure 6: Power-on with IGT held low before switching on operating voltage at BATT+
3.3.1.2 Turn on TC65 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 pin while TC65 is off, and the battery voltage is above the undervoltage
lockout threshold, processor controlled fast charging starts (see Section 3.5.6). TC65 enters
a restricted mode, referred to as Charge-only mode where only the charging algorithm will be
launched.
During the Charge-only mode TC65 is neither logged on to the GSM network nor are the
serial interfaces fully accessible. To switch to normal operation and log on to the GSM
network, the IGT line needs to be activated as described in Section 3.3.1.