LPWA Module Series
BG77 Hardware Design
BG77_Hardware_Design 7 / 76
Figure Index
FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 14
FIGURE 2: PIN ASSIGNMENT (TOP VIEW) .................................................................................................... 16
FIGURE 3: SLEEP MODE APPLICATION VIA UART ...................................................................................... 28
FIGURE 4: STAR STRUCTURE OF THE POWER SUPPLY ........................................................................... 29
FIGURE 5: TURN ON THE MODULE USING DRIVING CIRCUIT ................................................................... 30
FIGURE 6: TURN ON THE MODULE USING KEYSTROKE ........................................................................... 31
FIGURE 7: TIMING OF TURNING ON MODULE ............................................................................................. 31
FIGURE 8: TIMING OF TURNING OFF MODULE ........................................................................................... 32
FIGURE 9: TIMING OF RESET MODULE ........................................................................................................ 33
FIGURE 10: REFERENCE CIRCUIT OF RESET_N BY USING DRIVING CIRCUIT ...................................... 33
FIGURE 11: REFERENCE CIRCUIT OF RESET_N BY USING BUTTON ...................................................... 34
FIGURE 12: REFERENCE CIRCUIT OF PON_TRIG CIRCUIT ....................................................................... 35
FIGURE 13: REFERENCE CIRCUIT OF (U)SIM INTERFACE WITH AN 8-PIN (U)SIM CARD CONNECTOR
................................................................................................................................................................... 36
FIGURE 14: REFERENCE CIRCUIT OF (U)SIM INTERFACE WITH A 6-PIN (U)SIM CARD CONNECTOR 36
FIGURE 15: REFERENCE DESIGN OF USB PHY .......................................................................................... 38
FIGURE 16: REFERENCE DESIGN OF USB INTERFACE ............................................................................. 38
FIGURE 17: REFERENCE CIRCUIT WITH TRANSLATOR CHIP ................................................................... 41
FIGURE 18: REFERENCE CIRCUIT WITH TRANSISTOR CIRCUIT .............................................................. 42
FIGURE 19: REFERENCE CIRCUIT OF PCM APPLICATION WITH AUDIO CODEC ................................... 43
FIGURE 20: REFERENCE CIRCUIT OF THE NETWORK STATUS INDICATOR .......................................... 44
FIGURE 21: REFERENCE CIRCUIT OF STATUS ........................................................................................... 45
FIGURE 22: REFERENCE CIRCUIT OF USB_BOOT INTERFACE ................................................................ 46
FIGURE 23: REFERENCE CIRCUIT OF RF ANTENNA INTERFACE ............................................................ 54
FIGURE 24: MICROSTRIP LINE DESIGN ON A 2-LAYER PCB ..................................................................... 54
FIGURE 25: COPLANAR WAVEGUIDE LINE DESIGN ON A 2-LAYER PCB ................................................. 55
FIGURE 26: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE
GROUND) .................................................................................................................................................. 55
FIGURE 27: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE
GROUND) .................................................................................................................................................. 55
FIGURE 28: REFERENCE CIRCUIT OF GNSS ANTENNA INTERFACE ....................................................... 57
FIGURE 29: DIMENSIONS OF THE U.FL-R-SMT CONNECTOR (UNIT: MM) ............................................... 58
FIGURE 30: MECHANICALS OF U.FL-LP CONNECTORS ............................................................................. 59
FIGURE 31: SPACE FACTOR OF MATED CONNECTOR (UNIT: MM) .......................................................... 59
FIGURE 32: MODULE TOP AND SIDE DIMENSIONS .................................................................................... 66
FIGURE 33: MODULE BOTTOM DIMENSIONS (BOTTOM VIEW) ................................................................. 67
FIGURE 34: RECOMMENDED FOOTPRINT (TOP VIEW) .............................................................................. 68
FIGURE 35: TOP VIEW OF THE MODULE ...................................................................................................... 69
FIGURE 36: BOTTOM VIEW OF THE MODULE .............................................................................................. 69
FIGURE 37: RECOMMENDED REFLOW SOLDERING THERMAL PROFILE ............................................... 71
FIGURE 38: TAPE DIMENSIONS ..................................................................................................................... 72
