SIM Tech SIM900D HD Manual page 19

SIM900D Hardware Design
detecting
inserting。
GND Ground
Power on or power off
PIN NAME I/O DESCRIPTION
PWRKEY I Power on/off the system.
Audio interfaces
PIN NAME I/O DESCRIPTION
MIC1P I Positive and negative
MIC1N voiceband input
MIC2P I Auxiliary positive and
MIC2N negative voiceband input
SPK1P O Positive and negative
SPK1N voiceband output
SPK2P O Auxiliary positive and
SPK2N negative voiceband output
AGND Analog ground
GERNERAL PURPOSE input/output
PIN NAME I/O DESCRIPTION
STATUS O Indicate working status
NETLIGHT O Indicate net status
DISP_DATA I/O
DISP _CLK O
Display interface
DISP _CS O
DISP _D/C O
GPO1 O Normal Output Port
KBR0 I/O Normal Output/Input Port
Serial port
SIM900D_HD_V1.02
the charger Vnorm=5.0V
DC CHARACTERISTICS
VILmax=1.2V
VIHmin=2.6V
VIHmax=3.3V
VILmin= 0V
DC CHARACTERISTICS
Audio DC Characteristics refer to
chapter 3.10
DC CHARACTERISTICS
VILmax=0.4V
VIHmin=2.4V
VILmin= 0V
VIHmax= 2.95
VOHmin= 2.7V
VOLmax=0.1V
VOHmax= 2.95V
VOLmin= 0V
19
No need an
external pull-up
resistor.
COMMENT
If unused keep
open.
If unused keep
open.
If unused keep
open.
If unused keep
open.
Separate ground
connection for
external audio
circuits.
If unused keep
open.
COMMENT
If unused keep
open
If unused keep
open
If unused keep
open
If unused keep
open
09.04.2010