SimCom SIM900 Hardware Design

SIM900 Hardware Design
Figure Index
FIGURE 1: SIM900 FUNCTIONAL DIAGRAM ........................................................................................................... 15
FIGURE 2: TOP VIEW OF SIM900 EVB ....................................................................................................................... 16
FIGURE 3: REFERENCE CIRCUIT OF THE VBAT INPUT ........................................................................................ 22
FIGURE 4: REFERENCE CIRCUIT OF THE SOURCE POWER SUPPLY INPUT..................................................... 22
FIGURE 5: VBAT VOLTAGE DROP DURING TRANSMIT BURST........................................................................... 23
FIGURE 6: TURN ON SIM900 USING DRIVING CIRCUIT ....................................................................................... 24
FIGURE 7: TURN ON SIM900 USING BUTTON......................................................................................................... 24
FIGURE 8: TIMING OF TURN ON SYSTEM USING PWRKEY ................................................................................ 25
FIGURE 9: TURN ON SIM900 USING DRIVING CIRCUIT ....................................................................................... 25
FIGURE 10: TURN ON SIM900 USING BUTTON....................................................................................................... 26
FIGURE 11: TIMING OF TURN ON SYSTEM USING PWRKEY AND PWRKEY_OUT ......................................... 26
FIGURE 12: TIMING OF TURN OFF SYSTEM USING PWRKEY............................................................................. 27
FIGURE 13: TIMING OF TURN OFF SYSTEM USING PWRKEY AND PWRKEY_OUT........................................ 27
FIGURE 14: TIMING OF RESTART SYSTEM ............................................................................................................. 29
FIGURE 15: STATE TRANSITION ................................................................................................................................30
FIGURE 16: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ......................................................................... 31
FIGURE 17: RTC SUPPLY FROM RECHARGEABLE BATTERY .............................................................................. 31
FIGURE 18: RTC SUPPLY FROM CAPACITOR .......................................................................................................... 31
FIGURE 19: SEIKO XH414H-IV01E CHARGE CHARACTERISTIC ......................................................................... 32
FIGURE 20: CONNECTION OF THE SERIAL INTERFACES..................................................................................... 33
FIGURE 21: CONNECTION OF SOFTWARE UPGRADE AND SOFTWARE DEBUG ............................................. 35
FIGURE 22: RS232 LEVEL CONVERTER CIRCUIT................................................................................................... 35
FIGURE 23: SPEAKER INTERFACE CONFIGURATION ........................................................................................... 36
FIGURE 24: SPEAKER INTERFACE WITH AMPLIFIER CONFIGURATION .......................................................... 36
FIGURE 25: MICROPHONE INTERFACE CONFIGURATION................................................................................... 37
FIGURE 26: EARPHONE INTERFACE CONFIGURATION........................................................................................ 37
FIGURE 27: REFERENCE CIRCUIT OF THE 8 PINS SIM CARD.............................................................................. 39
FIGURE 28: REFERENCE CIRCUIT OF THE 6 PINS SIM CARD.............................................................................. 40
FIGURE 29: AMPHENOL C707 10M006 512 2 SIM CARD HOLDER........................................................................ 40
FIGURE 30: MOLEX 91228 SIM CARD HOLDER ...................................................................................................... 41
FIGURE 31: REFERENCE CIRCUIT OF THE KEYPAD INTERFACE ....................................................................... 43
FIGURE 32: ARCHITECTURE OF ADC ....................................................................................................................... 44
FIGURE 33: SIM900 SERVICES AS RECEIVER.......................................................................................................... 45
FIGURE 34: SIM900 SERVICES AS CALLER.............................................................................................................. 45
FIGURE 35: REFERENCE CIRCUIT OF NETLIGHT .................................................................................................. 46
FIGURE 36: RESET TIMING ......................................................................................................................................... 47
FIGURE 37: TOP AN SIDE MECHANICAL DIMENSIONS OF MODULE （UNIT: MM）.................................... 53
FIGURE 38：BOTTOM MECHANICAL DIMENSIONS OF MODULE （UNIT: MM）......................................... 54
FIGURE 39: RECOMMENDED PCB DECAL（UNIT: MM） .................................................................................... 54
FIGURE 40: TOP VIEW OF THE SIM900 ..................................................................................................................... 55
FIGURE 41: SIM900 PIN OUT DIAGRAM (TOP VIEW)............................................................................................. 56
FIGURE 42: THE RAMP-SOAK-SPIKE REFLOW PROFILE OF SIM900.................................................................. 58
SIM900_HD_V1.05 06.23.2010
6

SimCom SIM900 Specifications

General

Brand	SimCom
Model	SIM900
Category	Modem
Language	English