User's Manual

LE920A4 HW User Guide Miscellaneous Functions
Doc#: 1VV0301261 Indication of Network Service Availability
Rev. 4.3 Page 93 of 123 2017-12-07
9. Miscellaneous Functions
Indication of Network Service Availability
The STAT_LED pin status shows information on the network service availability and call
status. In the module, the STAT_LED usually needs an external transistor to drive an
external LED. Table 42 shows the device status corresponding to the pin status:
Table 42: Network Service Availability Indication
LED Status Device Status
Permanently off Device off
Fast blinking (Period 1s, T
on
0,5s) Net search / Not registered / Turning off
Slow blinking (Period 3s, T
on
0,3s) Registered full service
Permanently on A call is active
Figure 22: Status LED Reference Circuit
RTC – Real Time Clock
The RTC within the module does not have a dedicated RTC supply pin. The RTC block is
supplied by the VBATT supply.
If the battery is removed, the RTC function is not maintained. Therefore, VBATT must be
supplied continuously for maintaining the internal RTC function.
In Power OFF mode, the average current consumption is ~25 uA.
VAUX Power Output
A regulated power supply output is provided to supply power to small devices from the
module. This output is active when the module is ON and goes OFF when the module is
shut down. The operating range characteristics of the supply are as follows: