Product Info

Smart LTE Module Series
SC20 Hardware Design
SC20_Hardware_Design 8 / 130
Figure Index
FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 22
FIGURE 2: PIN ASSIGNMENT (TOP VIEW)..................................................................................................... 24
FIGURE 3: VOLTAGE DROP SAMPLE ............................................................................................................. 36
FIGURE 4: STAR STRUCTURE OF THE POWER SUPPLY............................................................................ 37
FIGURE 5: REFERENCE CIRCUIT OF POWER SUPPLY .............................................................................. 37
FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT ................................................................... 38
FIGURE 7: TURN ON THE MODULE USING KEYSTROKE ........................................................................... 39
FIGURE 8: TIMING OF TURNING ON MODULE ............................................................................................. 39
FIGURE 9: TIMING OF TURNING OFF MODULE ........................................................................................... 40
FIGURE 10: RTC POWERED BY COIN CELL ................................................................................................. 40
FIGURE 11: RTC POWERED BY CAPACITOR ................................................................................................ 41
FIGURE 12: REFERENCE DESIGN FOR BATTERY CHARGING CIRCUIT ................................................... 42
FIGURE 13: USB INTERFACE REFERENCE DESIGN (OTG IS NOT SUPPORTED) ................................... 44
FIGURE 14: USB INTERFACE REFERENCE DESIGN (OTG IS SUPPORTED) ............................................ 44
FIGURE 15: REFERENCE CIRCUIT WITH LEVEL TRANSLATOR CHIP (FOR UART1) ............................... 46
FIGURE 16: RS-232 LEVEL MATCH CIRCUIT (FOR UART1) ......................................................................... 46
FIGURE 17: REFERENCE CIRCUIT FOR (U)SIM INTERFACE WITH AN 8-PIN (U)SIM CARD CONNECTOR
................................................................................................................................................................... 48
FIGURE 18: REFERENCE CIRCUIT FOR (U)SIM INTERFACE WITH A 6-PIN (U)SIM CARD CONNECTOR
................................................................................................................................................................... 48
FIGURE 19: REFERENCE CIRCUIT FOR SD CARD INTERFACE ................................................................. 50
FIGURE 20: REFERENCE CIRCUIT FOR MOTOR CONNECTION ................................................................ 55
FIGURE 21: REFERENCE CIRCUIT DESIGN FOR LCM INTERFACE ........................................................... 57
FIGURE 22: REFERENCE DESIGN FOR EXTERNAL BACKLIGHT DRIVING CIRCUIT ............................... 58
FIGURE 23: REFERENCE CIRCUIT DESIGN FOR TP INTERFACE .............................................................. 59
FIGURE 24: REFERENCE CIRCUIT DESIGN FOR REAR CAMERA INTERFACE ........................................ 61
FIGURE 25: REFERENCE CIRCUIT DESIGN FOR FRONT CAMERA INTERFACE ...................................... 62
FIGURE 26: REFERENCE CIRCUIT DESIGN FOR MICROPHONE INTERFACES ....................................... 66
FIGURE 27: REFERENCE CIRCUIT DESIGN FOR RECEIVER INTERFACE ................................................ 66
FIGURE 28: REFERENCE CIRCUIT DESIGN FOR HEADPHONE INTERFACE ........................................... 67
FIGURE 29: REFERENCE CIRCUIT DESIGN FOR LOUDSPEAKER INTERFACE ....................................... 67
FIGURE 30: REFERENCE CIRCUIT DESIGN FOR EMERGENCY DOWNLOAD INTERFACE ..................... 68
FIGURE 31: REFERENCE CIRCUIT DESIGN FOR MAIN AND RX-DIVERSITY ANTENNA INTERFACES .. 78
FIGURE 32: MICROSTRIP DESIGN ON A 2-LAYER PCB ............................................................................... 79
FIGURE 33: COPLANAR WAVEGUIDE DESIGN ON A 2-LAYER PCB ........................................................... 79
FIGURE 34: COPLANAR WAVEGUIDE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE GROUND)
................................................................................................................................................................... 79
FIGURE 35: COPLANAR WAVEGUIDE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE GROUND)
................................................................................................................................................................... 80
FIGURE 36: REFERENCE CIRCUIT DESIGN FOR WI-FI/BT ANTENNA ....................................................... 81
FIGURE 37: REFERENCE CIRCUIT DESIGN FOR GNSS PASSIVE ANTENNA ........................................... 82