SE868Kx-Ax Family Product User Guide
1VV0301201 Rev. 5
Page 49 of 83
2021-07-15
Not Subject to NDA
9.5.1.2.
Logic Levels
–
Outputs
TX0, TX1, and 1PPS
Signal
Symbol
Min
Typ
Max
Units
Output Voltage (L)
Vol
0.4
V
Output Voltage (H)
Voh
2.14
2.89
V
Normal Current (L)
Iol
-2
mA
Output Current (H)
Ioh
-2
mA
Table 30: Output Logic Levels: TX and 1PPS
9.5.2.
Control and Input Signals
9.5.2.1.
RESET-N
The Reset-N input is a low true input to reset the receiver to the default starting state.
This signal is not required for the module to operate properly, so this pin may be left
unconnected.
However, it is recommended to bring it out to a test point.
If used the signal can only be driven low, never high since it has an internal pullup.
The logic levels are shown in Table 28: Input Logic Levels: RX and Reset-N.
9.5.2.2.
FORCE_ON (SE868-A and SE868K3-Ax only)
For typical operation, connect this pin through a 10 K
Ω
resistor to ground to create a
pulldown (which will prevent noise from accidentally activating this pin).
Upon command, the module will enter the backup (low power) state.
To exit this state, drive the Force-on signal high (true) to force the module to return to
the full power state.
Force-on should be held high until the PMTK101 message is received (about 1 second),
then released to logic low.
If Force-on is high when a low-power command is received, the module will enter the
Standby (stop) state rather than the Backup state, since the PMU is still on.
This signal is only available on the SE868-A and SE868K3-Ax modules.
Note: This pin has a maximum input voltage of 3.4 V (which is lower
than the max for Vcc or Vbatt).
Logic levels are shown in Table 29: Input Logic Levels: Force_On.
