Users Manual

GSM/GPRS Module Series
M66 Hardware Design
M66_Hardware_Design Confidential / Released 20 / 82
EXT external circuit. V
O
min=2.7V
V
O
norm=2.8V
I
O
max=20mA
keep this pin
open.
2. Recommend
to add a
2.2~4.7uF
bypass
capacitor,
when using
this pin for
power supply.
GND
27,34
36,37
40,41
Ground
Turn on/off
PIN Name PIN No. I/O Description DC Characteristics Comment
PWRKEY 7 DI
Power on/off key. PWRKEY
should be pulled down for a
moment to turn on or turn off
the system.
V
IL
max=
0.1×VBAT
V
IH
min=
0.6×VBAT
V
IH
max=3.1V
Audio Interface
PIN Name PIN No. I/O Description DC Characteristics Comment
MICP
MICN
3,
4
AI
Positive and negative voice
input
Refer to Section 3.8
If unused, keep
these pins
open.
SPK1P
SPK1N
5,
6
AO
Channel 1 positive and
negative voice output
If unused, keep
these pins
open.
Support both
voice and
ringtone
output.
SPK2P 2 AO Channel 2 voice output
AGND 1
Analog ground. Separate
ground connection for
external audio circuits.
If unused, keep
this pin open.
Network Status Indicator