MeiG_SLM156_Hardware Design Manual
MeiG Smart Technology Co., Ltd
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3.7 Turn on and off
SLM156 supports power-on button. You can query the output high level of VDD_EXT pin to see if the
module is turned on.
3.7.1 Turn on Module Using the POWER_ON/OFF
Table 7 Description of POWER_ON/OFF pin
Pin name
Pin number
Function
DC features
Description
POWER_ON/OFF
53
Turn on/ off the
module
VIHmax=2.1V
VIHmin=1.3V
VILmax=0.5V
When SLM156 is in power down mode, it can be turned on to normal mode by driving the
POWER_ON/OFF pin to a low level for at least 100ms. It is suggested that you use an open set driver
circuit to control POWER_ON/OFF pin.
Figure 3 Turn on the Module Using Driving Circuit
The other way to control the POWER_ON/OFF is using a button directly. A TVS component is
indispensable to be placed nearby the button for ESD protection. A reference circuit is shown in the
following figure:
Figure 4 Turn on the Module Using Keystroke
