LTE Standard Module Series
EG91 Series Hardware Design
EG91_Series_Hardware_Design 9 / 106
Figure Index
Figure 1: Functional Diagram .................................................................................................................. 20
Figure 2: Pin Assignment (Top View) ....................................................................................................... 22
Figure 3: Sleep Mode Application via UART ............................................................................................ 31
Figure 4: Sleep Mode Application with USB Remote Wakeup ................................................................. 32
Figure 5: Sleep Mode Application with RI ................................................................................................ 33
Figure 6: Sleep Mode Application without Suspend Function .................................................................. 33
Figure 7: Power Supply Limits during Burst Transmission ...................................................................... 35
Figure 8: Star Structure of Power Supply ................................................................................................ 36
Figure 9: Reference Circuit of Power Supply .......................................................................................... 36
Figure 10: Turn on the Module Using Driving Circuit ............................................................................... 37
Figure 11: Turn on the Module Using Button ........................................................................................... 38
Figure 12: Timing of Turning on Module .................................................................................................. 38
Figure 13: Timing of Turning off Module .................................................................................................. 39
Figure 14: Reference Circuit of RESET_N by Using Driving Circuit ........................................................ 40
Figure 15: Reference Circuit of RESET_N by Using Button .................................................................... 41
Figure 16: Timing of Resetting Module .................................................................................................... 41
Figure 17: Reference Circuit of (U)SIM Interface with an 8-pin (U)SIM Card Connector ......................... 43
Figure 18: Reference Circuit of (U)SIM Interface with a 6-pin (U)SIM Card Connector ........................... 43
Figure 19: Reference Circuit of USB Interface ........................................................................................ 45
Figure 20: Reference Circuit with Translator Chip ................................................................................... 47
Figure 21: Reference Circuit with Transistor Circuit ................................................................................ 48
Figure 22: Primary Mode Timing ............................................................................................................. 49
Figure 23: Auxiliary Mode Timing ............................................................................................................ 49
Figure 24: Reference Circuit of PCM Application with Audio Codec ........................................................ 50
Figure 25: Reference Circuit of SPI Interface with Peripherals ............................................................... 51
Figure 26: Reference Circuit of Network Status Indicator ........................................................................ 52
Figure 27: Reference Circuit of STATUS ................................................................................................. 53
Figure 28: Reference Circuit of USB_BOOT Interface ............................................................................ 55
Figure 29: Timing Sequence for Entering Emergency Download Mode .................................................. 56
Figure 30: Reference Circuit of RF Antenna Interface ............................................................................. 61
Figure 31: Microstrip Design on a 2-layer PCB ....................................................................................... 61
Figure 32: Coplanar Waveguide Design on a 2-layer PCB ...................................................................... 62
Figure 33: Coplanar Waveguide Design on a 4-layer PCB (Layer 3 as Reference Ground) ................... 62
Figure 34: Coplanar Waveguide Design on a 4-layer PCB (Layer 4 as Reference Ground) ................... 62
Figure 35: Reference Circuit of GNSS Antenna ...................................................................................... 64
Figure 36: Dimensions of the U.FL-R-SMT Connector (Unit: mm) .......................................................... 65
Figure 37: Mechanicals of U.FL-LP Connectors ...................................................................................... 66
Figure 38: Space Factor of Mated Connector (Unit: mm) ........................................................................ 66
Figure 39: Referenced Heatsink Design (Heatsink at the Top of the Module) ......................................... 88
Figure 40: Referenced Heatsink Design (Heatsink at the Backside of Customers’ PCB) ........................ 88
Figure 41: Module Top and Side Dimensions .......................................................................................... 90
