Smart Machine Smart Decision
SIM800C_Hardware_Design_V1.00 7 2014-10-30
Figure Index
FIGURE 1: SIM800C FUNCTIONAL DIAGRAM ......................................................................................................... 12
FIGURE 2: PIN ASSIGNMENT (TOP VIEW) ................................................................................................................ 13
FIGURE 3: DIMENSIONS OF SIM800C (UNIT: MM) ................................................................................................. 15
FIGURE 4: RECOMMENDED PCB FOOTPRINT OUTLINE (UNIT: MM) ................................................................ 16
FIGURE 5: REFERENCE CIRCUIT OF THE VBAT INPUT......................................................................................... 17
FIGURE 6: REFERENCE CIRCUIT OF THE LDO POWER SUPPLY ......................................................................... 17
FIGURE 7: REFERENCE CIRCUIT OF THE DC-DC POWER SUPPLY ..................................................................... 18
FIGURE 8: VBAT VOLTAGE DROP DURING TRANSMIT BURST ........................................................................... 18
FIGURE 9: THE MINIMAL VBAT VOLTAGE REQUIREMENT AT VBAT DROP .................................................... 19
FIGURE 10: POWERED ON/DOWN MODULE USING TRANSISTOR ..................................................................... 19
FIGURE 11: POWERED ON/DOWN MODULE USING BUTTON ............................................................................. 19
FIGURE 12: TIMING OF POWER ON MODULE ......................................................................................................... 20
FIGURE 13: TIMING OF POWER DOWN SIM800C BY PWRKEY ........................................................................... 21
FIGURE 14: TIMING OF RESTART SIM800C .............................................................................................................. 22
FIGURE 15: RTC SUPPLY FROM CAPACITOR ........................................................................................................... 24
FIGURE 16: RTC SUPPLY FROM NON-CHARGEABLE BATTERY.......................................................................... 24
FIGURE 17: RTC SUPPLY FROM RECHARGEABLE BATTERY .............................................................................. 24
FIGURE 18: CONNECTION OF THE SERIAL INTERFACES ..................................................................................... 26
FIGURE 19: RESISTOR MATCHING CIRCUIT ........................................................................................................... 27
FIGURE 20 : DIODE ISOLATION CIRCUIT ................................................................................................................. 27
FIGURE 21: TX LEVEL MATCHING CIRCUIT ........................................................................................................... 27
FIGURE 22: RX LEVEL MATCHING CIRCUIT ........................................................................................................... 28
FIGURE 23: USB REFERENCE CIRCUIT .................................................................................................................... 28
FIGURE 24: CONNECTION FOR SOFTWARE UPGRADING AND DEBUGGING .................................................. 29
FIGURE 25: UART1_RI BEHAVIOUR OF VOICE CALLING AS A RECEIVER ....................................................... 30
FIGURE 26: UART1_RI BEHAVIOUR OF DATA CALLING AS A RECEIVER ......................................................... 30
FIGURE 27: UART1_RI BEHAVIOUR OF URC OR RECEIVE SMS .......................................................................... 30
FIGURE 28: UART1_RI BEHAVIOUR AS A CALLER ................................................................................................. 31
FIGURE 29: SPEAKER REFERENCE CIRCUIT .......................................................................................................... 32
FIGURE 30: MICROPHONE REFERENCE CIRCUIT .................................................................................................. 32
FIGURE 31: REFERENCE CIRCUIT OF THE 8-PIN SIM CARD HOLDER ............................................................... 34
FIGURE 32: REFERENCE CIRCUIT OF THE 6-PIN SIM CARD HOLDER ............................................................... 34
FIGURE 33: MOLEX 91228 SIM CARD HOLDER....................................................................................................... 35
FIGURE 34: AMPHENOL C707 10M006 512 SIM CARD HOLDER ........................................................................... 36
FIGURE 35: REFERENCE CIRCUIT OF NETLIGHT................................................................................................... 37
FIGURE 36: RF_SYNC SIGNAL DURING TRANSMIT BURST ................................................................................ 39
FIGURE 37: GSM ANTENNA MATCHING CIRCUIT.................................................................................................. 39
FIGURE 38: GSM ANTENNA MATCHING CIRCUIT WITHOUT RF CONNECTOR ............................................... 40
FIGURE 40: PIN ASSIGNMENT .................................................................................................................................... 41
FIGURE 41: TOP AND BOTTOM VIEW OF SIM800C ................................................................................................ 48
FIGURE 42: TYPICAL SOLDER REFLOW PROFILE OF LEAD-FREE PROCESSES .............................................. 48