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FIBOCOM SC138-
NA
Series Hardware Guide
39/88
Table 3-5 On/off control signals
Pin Name
Pin No.
I/O
Description
Remarks
KEY_PWR_N 123
DI
Active low, can be used as on/off, restart,
sleep/wakeup control.
-
3.2.1.1
Startup
After the VBAT is powered on, the trigger module starts up through pulling down the KEY_PWR_N pin
for 2s to 8s. The design of key startup circuit and OC drive startup reference circuit is shown in the
following figure:
Figure 3-4 Key startup circuit
Figure 3-5 OC drive startup circuit
The startup timing sequence is shown in the following figure:
S 1
K E Y _P W R _N
C lose to S 1
T V S
1K
100pF
2s~8s
10K
47K
K E Y _P W R _N
