hardware design v2.00

Smart Machine Smart Decision
SIM908_Hardware Design_V2.00 2012.05.07
6
Figure Index
FIGURE 1: SIM908 FUNCTIONAL DIAGRAM ........................................................................................................... 12
FIGURE 2: SIM908 PIN OUT DIAGRAM (TOP VIEW) ............................................................................................... 13
FIGURE 3: DIMENSIONS OF SIM908（UNIT: MM）................................................................................................ 16
FIGURE 4: RECOMMENDED PCB FOOTPRINT OUTLINE（UNIT: MM）............................................................ 16
FIGURE 5: U.FL-R-SMT (UNIT:MM)............................................................................................................................ 17
FIGURE 6: U.FL SERIES RF ADAPTER CABLE (UNIT:MM) .................................................................................... 17
FIGURE 7: REFERENCE CIRCUIT OF THE LDO POWER SUPPLY ......................................................................... 18
FIGURE 8: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY..................................................................... 18
FIGURE 9: VBAT VOLTAGE DROP DURING TRANSMIT BURST........................................................................... 19
FIGURE 10: THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP .................................................. 19
FIGURE 11: POWERED ON/DOWN MODULE USING TRANSISTOR ..................................................................... 19
FIGURE 12: POWERED ON/DOWN MODULE USING BUTTON ............................................................................. 20
FIGURE 13: TIMING OF POWER ON MODULE......................................................................................................... 20
FIGURE 14: TIMING OF POWER DOWN SIM908 BY PWRKEY .............................................................................. 21
FIGURE 15: TIMING OF RESTART SIM908 ................................................................................................................ 22
FIGURE 16: SIM908 WITH BATTERY CHARGER AND PACK CONNECTION....................................................... 24
FIGURE 17: RTC SUPPLY FROM CAPACITOR........................................................................................................... 28
FIGURE 18: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ......................................................................... 28
FIGURE 19: RTC SUPPLY FROM RECHARGEABLE BATTERY .............................................................................. 28
FIGURE 20: SEIKO XH414H-IV01E CHARGE-DISCHARGE CHARACTERISTIC ................................................. 28
FIGURE 21: CONNECTION OF THE SERIAL INTERFACES..................................................................................... 29
FIGURE 22: CONNECTION OF RXD AND TXD ONLY ............................................................................................. 29
FIGURE 23: CONNECTION FOR SOFTWARE UPGRADING AND DEBUGGING .................................................. 30
FIGURE 24: SPEAKER REFERENCE CIRCUIT .......................................................................................................... 31
FIGURE 25: SPEAKER WITH AMPLIFIER REFERENCE CIRCUIT ......................................................................... 31
FIGURE 26 : MICROPHONE REFERENCE CIRCUIT................................................................................................. 32
FIGURE 27: EARPHONE REFERENCE CIRCUIT....................................................................................................... 32
FIGURE 28: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER............................................................... 33
FIGURE 29: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER............................................................... 34
FIGURE 30: AMPHENOL C707 10M006 5122 SIM CARD HOLDER......................................................................... 34
FIGURE 31: MOLEX 91228 SIM CARD HOLDER ...................................................................................................... 35
FIGURE 32: REFERENCE CIRCUIT OF THE KEYPAD INTERFACE ....................................................................... 36
FIGURE 33: RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER...................................................................... 37
FIGURE 34: RI BEHAVIOUR OF DATA CALLING AS A RECEIVER........................................................................ 38
FIGURE 35: RI BEHAVIOUR OF URC OR RECEIVE SMS ........................................................................................ 38
FIGURE 36: RI BEHAVIOUR AS A CALLER ............................................................................................................... 38
FIGURE 37: REFERENCE CIRCUIT OF NETLIGHT .................................................................................................. 39
FIGURE 38: THE RF INTERFACE OF MODULE......................................................................................................... 40
FIGURE 39: GSM ANTENNA MATCHING CIRCUIT ................................................................................................. 40
FIGURE 40: GPS ANTENNA MATCHING CIRCUIT................................................................................................... 42
FIGURE 41: MODULE LABEL INFORMATION.......................................................................................................... 49