Quectel Smart LTE Module Series, Hardware Design

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Smart LTE Module Series
SC650T Hardware Design
SC650T_Hardware_Design 8 / 131
Figure Index
FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 18
FIGURE 2: PIN ASSIGNMENT (TOP VIEW) .................................................................................................... 21
FIGURE 3: VOLTAGE DROP SAMPLE ............................................................................................................. 39
FIGURE 4: STAR STRUCTURE OF POWER SUPPLY .................................................................................... 40
FIGURE 5: REFERENCE CIRCUIT OF POWER SUPPLY .............................................................................. 40
FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT ................................................................... 41
FIGURE 7: TURN ON THE MODULE USING KEYSTROKE ........................................................................... 42
FIGURE 8: TIMING OF TURNING ON MODULE ............................................................................................. 42
FIGURE 9: TIMING OF TURNING OFF MODULE ........................................................................................... 43
FIGURE 10: RTC POWERED BY COIN CELL ................................................................................................. 43
FIGURE 11: REFERENCE DESIGN FOR BATTERY CHARGING CIRCUIT ................................................... 46
FIGURE 12: USB 2.0 INTERFACE REFERENCE DESIGN ............................................................................. 48
FIGURE 13: USB TYPE-C INTERFACE REFERENCE DESIGN ..................................................................... 48
FIGURE 14: REFERENCE CIRCUIT WITH LEVEL TRANSLATOR CHIP (FOR UART5) ............................... 50
FIGURE 15: RS232 LEVEL MATCH CIRCUIT (FOR UART5) .......................................................................... 51
FIGURE 16: REFERENCE CIRCUIT FOR (U)SIM INTERFACE WITH AN 8-PIN (U)SIM CARD CONNECTOR
................................................................................................................................................................... 52
FIGURE 17: REFERENCE CIRCUIT FOR (U)SIM INTERFACE WITH A 6-PIN (U)SIM CARD CONNECTOR
................................................................................................................................................................... 53
FIGURE 18: REFERENCE CIRCUIT FOR SD CARD INTERFACE ................................................................. 54
FIGURE 19: REFERENCE CIRCUIT FOR VIBRATOR CONNECTION ........................................................... 62
FIGURE 20: REFERENCE CIRCUIT DESIGN FOR LCM0 INTERFACE ......................................................... 64
FIGURE 21: REFERENCE CIRCUIT DESIGN FOR LCM1 INTERFACE ......................................................... 65
FIGURE 22: REFERENCE DESIGN OF LCM EXTERNAL BACKLIGHT DRIVING CIRCUIT ......................... 65
FIGURE 23: REFERENCE CIRCUIT DESIGN FOR TOUCH PANEL INTERFACES ....................................... 67
FIGURE 24: REFERENCE CIRCUIT DESIGN FOR TWO-CAMERA APPLICATIONS .................................... 70
FIGURE 25: REFERENCE CIRCUIT DESIGN FOR FLASHLIGHT INTERFACES .......................................... 73
FIGURE 26: REFERENCE CIRCUIT DESIGN FOR ANALOG ECM-TYPE MICROPHONE ........................... 76
FIGURE 27: REFERENCE CIRCUIT DESIGN FOR MEMS-TYPE MICROPHONE ........................................ 76
FIGURE 28:REFERENCE CIRCUIT DESIGN FOR DIGITAL MICROPHONE ................................................. 77
FIGURE 29: REFERENCE CIRCUIT DESIGN FOR EARPIECE INTERFACE ................................................ 77
FIGURE 30: REFERENCE CIRCUIT DESIGN FOR HEADPHONE INTERFACE ........................................... 78
FIGURE 31: REFERENCE CIRCUIT DESIGN FOR LOUDSPEAKER INTERFACE ....................................... 78
FIGURE 32: REFERENCE CIRCUIT DESIGN FOR EMERGENCY DOWNLOAD INTERFACE ..................... 79
FIGURE 33: REFERENCE CIRCUIT DESIGN FOR LED INTERFACES ......................................................... 80
FIGURE 34: REFERENCE CIRCUIT DESIGN FOR MAIN AND RX-DIVERSITY ANTENNA INTERFACES .. 89
FIGURE 35: MICROSTRIP LINE DESIGN ON A 2-LAYER PCB ...................................................................... 89
FIGURE 36: COPLANAR WAVEGUIDE LINE DESIGN ON A 2-LAYER PCB .................................................. 89
FIGURE 37: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE
GROUND) .................................................................................................................................................. 90
FIGURE 38: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE