M20 Hardware Design
VDD_EXT O Supply 2.8V voltage for
external circuit. By
measuring this pin, customer
can judge whether the
system is power on or off.
When the voltage is low, the
system is power off.
Otherwise, the system is
power on.
Vmax=2.9V
Vmin=2.7V
Vnorm=2.8V
Imax=20mA
1.If unused,
keep this pin
open
.
2.
Recommend
to add a
2.2~4.7uF
bypass
capacitor,
when using
this pin for
power supply.
GND
Digital
ground
Power on or power off
PIN NAME
I/O DESCRIPTION
DC CHARACTERISTICS COMMENT
PWRKEY
I
Voltage input for power
on/off key. PWRKEY should
be pulled down to turn on or
turn off the system.
Customer should keep
pressing this key for a
moment when turn on or turn
off the module.
VILmax=0.3*VBAT
VIHmin=0.7*VBAT
VImax=VBAT
Pull up to
VBAT
internally.
Emergency shutdown
PIN NAME
I/O DESCRIPTION
DC CHARACTERISTICS COMMENT
EMERG_OF
F
I
Voltage input for emergency
shutdown under emergent
situation. EMERG_OFF
should be pulled down for at
least 20ms to shutdown the
system in emergency. The
module can restart by
PWRKEY operation.
VILmax=0.4V
VIHmin=2.2V
V
open
max=2.8V
Open
drain/collecto
r driver
required in
cellular
device
application.
If unused,
keep this pin
open.
Audio interfaces
PIN NAME
I/O DESCRIPTION
DC CHARACTERISTICS COMMENT
MIC1P
MIC1N
I
Audio input channel 1.
Positive and negative voice
input.
Audio DC Characteristics
refer to chapter 3.10
No internal
microphone
bias supply. If
unused keep
these pins
open.
M20_HD_V1.01
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Quectel