SIM Tech SimCom SIM340 Hardware Design page 19

SIM340 Hardware Design
GND
Power on or power off
PIN NAME I/O
PWRKEY I
Audio interfaces
PIN NAME I/O
MIC1P I
MIC1N
MIC2P I
MIC2N
SPK1P O
SPK1N
SPK2P O
SPK2N
BUZZER O
AGND
General purpose input/output
PIN NAME I/O
KBC0~KB O/4mA
C4
KBR0~KB I/4mA
R4
DISP_DAT I/O/4m
SIM340_HD_V3.09
Otherwise, the system is power on.
DESCRIPTION
Voltage input for PWRKEY.
PWRKEY should be pulled low to
power on or power off the system.
The user should keep pressing the
key for a moment when power on
or power off the system because the
system need margin time in order
to assert the software.
DESCRIPTION
Positive and negative voice-band
input
Auxiliary positive and negative
voice-band input
Positive and negative voice-band
output
Auxiliary positive and negative
voice-band output
Buzzer output
Analog ground
DESCRIPTION
Keypad interface
LCD display interface
19
Digital ground
DC CHARACTERISTICS
VILmax=0.2*VBAT
VIHmin=0.6*VBAT
VImax=VBAT
DC CHARACTERISTICS
Audio DC Characteristics
refer to chapter 3.9.4
DC CHARACTERISTICS
VILmin=0V
VILmax=0.3 *VDD_EXT
VIHmin=0.7*VDD_EXT
VIHmax= VDD_EXT+0.3
VOLmin=GND
VOLmax=0.2V
VOHmin= VDD_EXT-0.2
VOHmax= VDD_EXT
18.03.2009
pull up to
VBAT
DC
If unused
keep pins
open
If unused
keep pins
open
If unused
keep pin open
Separate
ground
connection for
external audio
circuits.
If unused
keep pin open
Tri-out, If
unused keep
pins open
Pull up to
VEXT, if
unused keep
pins open
If unused