NB-IoT
Module Series
BC660K-GL Hardware Design
BC660K-GL_Hardware_Design 24 / 57
1. After the module is powered off, it can be turned on again only after its VBAT voltage drops below
0.7 V. The actual discharging time of VBAT needs to be determined based on circuit tests and
enough time margin should be left to avoid abnormal module startup.
2. The power-up time of VBAT must be within 10 ms.
3. It is recommended that the MCU retains a RESET_N controlling pin so that when the abnormal
power-on sequence causes the module to boot up abnormally, the RESET_N pin can make the
module reset so as to exit from the abnormal state.
4. After VBAT is powered on, RESET_N and BOOT automatically rise to high level due to internal
pull-ups.
3.6.2. Turn Off
The module can be turned off through cutting off its VBAT power supply.
VBAT
RESET_N
Delay > 5 ms
Figure 7: Turn-off Timing
3.6.3. Reset
Driving RESET_N low for at least 50 ms resets the module.
Table 9: Reset Pin Definition
Pin Name
Pin No.
Description
DC Characteristics
Comment
RESET_N
15
Reset the module.
V
IL
max = 0.42 V
V
IH
min = 1.33 V
V
IH
max = 2.2 V
Reset pull-down time
≥ 50 ms
Active low.
The reference designs for resetting the module are shown below. An open drain/collector driving circuit or
a button can be used to control the RESET_N pin.
NOTES
