Neoway Neo_M660A - Page 6

Neo_M660A GPRS Module Hardware User Guide
Copyright © Neoway Technology Co., Ltd
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Table of Figures
Figure 2-1 Top view of the M660A module ............................................................................................ 4
Figure 2-2 PCB foot print recommended for M660A (unit: mm) ........................................................... 8
Figure 3-1 Current peaks and voltage drops ............................................................................................ 9
Figure 3-2 Reference design d for the power supply ............................................................................. 10
Figure 3-3 Reference design of power supply control ........................................................................... 10
Figure 3-4 Reference design of power supply controlled by p-MOSFET ..............................................11
Figure 3-5 Reference designs of separated power supply ...................................................................... 12
Figure 3-6 VRTC reference design ........................................................................................................ 13
Figure 3-7 Turning on procedure ........................................................................................................... 13
Figure 3-8 Turning off procedure .......................................................................................................... 14
Figure 3-9 Reference circuit for ON/OFF controlled by low level ........................................................ 14
Figure 3-10 Reference circuit for power-on controlled by high level .................................................... 15
Figure 3-11 Reset circuit with triode separating .................................................................................... 15
Figure 3-12 Signal connection between DCE and DTE ........................................................................ 16
Figure 3-13 Recommended communication circuit between 3.3V MCU and UART ........................... 17
Figure 3-14 Recommended communication circuit between 5V MCU and UART .............................. 17
Figure 3-15 USB circuit ........................................................................................................................ 18
Figure 3-16 RING indicator for incoming call ...................................................................................... 20
Figure 3-17 RING indicator for SMS .................................................................................................... 20
Figure 3-18 Reference design of SIM card interface ............................................................................. 21
Figure 3-19 Reference of SIM card socket ............................................................................................ 21
Figure 3-20 LED indicator directly driven by high level ....................................................................... 22
Figure 3-21 LED indicator driven by transistor ..................................................................................... 22
Figure 3-22 Reference design of MIC differential connections ............................................................. 23
Figure 3-23 Reference design for common audio input ........................................................................ 24
Figure 3-24 Reference design for receiver output ................................................................................. 24
Figure 3-25 Coupling capacitor interfacing ........................................................................................... 25
Figure 3-26 Reference design for antenna interface .............................................................................. 25
Figure 3-27 RF layout reference ............................................................................................................ 26
Figure 3-28 Encapsulation specifications of Murata RF connector ....................................................... 26
Figure 3-29 RF connections................................................................................................................... 26