Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved
FIBOCOM FG621-LA Series Hardware Guide
Page 26 of 57
5 Functional Interface
5.1 Control Interface
Two control signals are used to open, shut down and reset the module. Pin definition is shown in the
following table:
Table 5-1 Control signal
Pin Name
I/O
Pin#
Description
RESET_N
DI
1
When the module is in operating mode, pull down RESET_N for at
least 2.1s (3s-8s recommended), and then release it, the module is
reset. Internally pulled up.
PWRKEY
DI
2
When the module is in power-off mode, pull down PWRKEY for at
least 1.6s (2s-3s recommended), and then release it, the module will
power on, when the module is in operating mode, pull down
PWRKEY for at least 2.1s (3s-8s recommended), and then release
it, the module will power off.
5.1.1 Power-on/Off
5.1.1.1 Power-on
When FG621-LA series module is in power-off mode, pull down PWRKEY pin for at least 1.6s, the module
will power on, it is recommended to use OC/OD drive circuit to control PWRKEY pin. The OC drive
reference circuit is shown as follows:
Figure 5-1 OC drive power-on reference circuit
The other way to control PWRKEY pin is to use a button switch, a TVS (ESD9X5VL-2/TR recommended)
should be located close to the button for ESD protection. The reference circuit is shown in Figure 5-2:
