Gemalto M2M GmbH AC75 Benutzerhandbuch

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AC65/AC75 Hardware Interface Description 
Confidential / Preliminary 
s
 
AC65/AC75_hd_v00.372 
Page 28 of 118 
2006-08-03 
3.3 
Power-Up / Power-Down Scenarios 
In general, be sure not to turn on AC65/AC75 while it is beyond the safety limits of voltage 
and temperature stated in Chapter 5.1. AC65/AC75 would immediately switch off after having 
started and detected these inappropriate conditions. In extreme cases this can cause 
permanent damage to the module.  
3.3.1 
Turn on AC65/AC75 
AC65/AC75 can be started in a variety of ways as described in the following sections: 
•  Hardware driven start-up by IGT line: starts Normal mode or Airplane mode (see Section 
•  Software controlled reset by AT+CFUN command: starts Normal mode or Airplane mode 
•  Hardware driven start-up by VCHARGE line: starts charging algorithm and Charge-only 
•  Wake-up from Power-down mode by using RTC interrupt: starts Airplane mode 
 
The option whether to start into Normal mode or Airplane mode depends on the settings 
made with the AT^SCFG command or AT+CALA. With AT+CALA, followed by AT^SMSO the 
module can be configured to restart into Airplane mode at a scheduled alarm time. Switching 
back and forth between Normal mode and Airplane mode is possible any time during 
operation by using the AT^SCFG command.  
 
After startup or mode change the following URCs indicate the module’s ready state: 
•  “SYSSTART” indicates that the module has entered Normal mode. 
•  “^SYSSTART AIRPLANE MODE” indicates that the module has entered Airplane mode. 
•  “^SYSSTART CHARGE ONLY MODE” indicates that the module has entered the 
Charge-only mode. 
These URCs are indicated only if the module is set to a fixed bit rate, i.e. they do not appear 
if autobauding is enabled (AT+IPR≠0). 
 
Detailed explanations on AT^SCFG, AT+CFUN, AT+CALA, Airplane mode and AT+IPR can 
be found in [1]. 
 
3.3.1.1 
Turn on AC65/AC75 Using Ignition Line IGT 
When AC65/AC75 is in Power-down mode or Charge-only mode, it can be started to Normal 
mode or Airplane mode by driving the IGT (ignition) line to ground. This must be 
accomplished with an open drain/collector driver to avoid current flowing into this pin.  
The module will start up when both of the following two conditions are met:  
•  The supply voltage applied at BATT+ must be in the operating range.  
•  The IGT line needs to be driven low for at least 400ms in Power-down mode or at least 
2s in Charge-only mode. When released IGT goes high and causes the module to start. 
 
Considering different strategies of host application design the figures below show two 
approaches to meet this requirement: The example in Figure 5 assumes that IGT is activated 
after BATT+ has already been applied. The example in Figure 6 assumes that IGT is held 
low before BATT+ is switched on. In either case, to power on the module, ensure that low 
state of IGT takes at least 400ms (Power-down mode) or 2s (Charge-only mode) from the 
moment the voltage at BATT+ is available. For Charge-only mode see also Chapter 3.5.6.