GSM/GPRS Module Series
M85 Hardware Design
M85_Hardware_Design Confidential / Released 19 / 88
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
EMERG_
OFF
17
I
Emergency off. Pulled
down for at least 40ms,
which will turn off the
module in case of
emergency. Use it only
when shutdown via
PWRKEY or AT command
cannot be achieved.
VILmax=0.45V
VIHmin=1.35V
Vopenmax=1.8V
Open
drain/collector
driver required in
cellular device
application.
If unused, keep
this pin open.
Module Indicator
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
STATUS
16
O
Indicate module’s
operating status. Output
high level when module
turns on, while output low
level when module turns
off.
VOHmin=
0.85×VDD_EXT
VOLmax=
0.15×VDD_EXT
If unused, keep
this pin open.
Audio Interface
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
MIC1P
MIC1N
9, 10
I
Channel 1 positive and
negative voice input
Refer to
Section 3.8
If unused, keep
these pins open.
MIC2P
MIC2N
7, 8
I
Channel 2 positive and
negative voice input
SPK1P
SPK1N
12, 11
O
Channel 1 positive and
negative voice output
1. If unused, keep
these pins open.
2. Support both
voice and
ringtone output.
SPK2P
5
O
Channel 2 voice output
AGND
6
Analog ground. Separate
ground connection for
external audio circuits.
If unused, keep
this pin open.
LOUDSPKN
LOUDSPKP
13, 14
O
Channel 3 positive and
negative voice output
1. If unused, keep
these pins open.
2. Integrate a
Class- AB
amplifier
internally.
3. Support both
voice and
