M660 GPRS Module User Manual Shenzhen Neoway Technology Co.,Ltd.
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Contents 1. Introduction ................................................................................................................................ 6 2. General Description ................................................................................................................... 6 3. Simplified Block Diagram ......................................................................................................... 6 4. Key Features ........................................................
9. Terms and Abbreviations......................................................................................................... 29 Shenzhen Neoway Technology Co., Ltd.
Document History Revision History Version Remarks Date Issue V3.0 Modified Version 2013-9 V3.1 Change receive sensitivity index 2013-10 V3.2 Change 24pin definition 2013-11 Shenzhen Neoway Technology Co., Ltd.
1. Introduction This document describes the hardware features of M660, and guides for the relevant application design. 2. General Description With the ultra-compact design, M660 is intended to be used in a wide range of applications, including industrial and consumer devices. M660 is a GSM/GPRS module with EDGE of downlink. It features with voice, SMS, and data services. 3. Simplified Block Diagram Figure 1 M660 Block Diagram Shenzhen Neoway Technology Co., Ltd.
4. Key Features Table1 M660 Key Features Feature Frequency Bands Implementation 850/900/1800/1900 MHz Quad-band Compliant with GSM/GPRS Phase2/2+ Sensitivity Transmit Power < -107dBm 850/900 Class4(2W) 1800/1900 Class1(1W) AT GSM07.
5. Product Specifications 5.1 Variants Variants M660-QUAD-AA0/A00 Frequencies 850/900/1800/1900MHz Quad-band Packages 28 Pin LCC 5.2 Dimension & Package Physical Characteristics Dimensions 22mm*18.4mm*2.7mm (Length*Width*Thickness) Weight 2.2 g Package 28 Pin LCC Figure 2 M660 Sketch Shenzhen Neoway Technology Co., Ltd.
5.3 Pin Description Table2 M660 pin definition Pin Signal I/O 2 VSIM SIM_CLK PWR 3 SIM_DATA 4 5 1 M660 Function Note 1.8/3.0V compatible. DO SIM supply voltage SIM clock DIO SIM data 5KΩ internal pull-up GND PWR GND DO AI SIM reset MIC+ Prompted by module 6 SIM_RST MICP 7 MICN AI MIC- Vi ≤ 200mVpp 8 EAR-L AO Earpiece output L Signal Ended Output. Can drive a 16Ω/32Ω earpiece directly. 9 EAR-R AO Earpiece output R Signal Ended Output.
5.4 PCB foot print Recommended foot print: Figure 3 Recommended foot print of M660 (all dimensions in millimeters) Note： Every other pitch not specified is 2.0mm. The circle on the top-right with a 1.3mm radius, defines a keep-out region, under which any copper or wire is inhibited, due to the RF test point here needs to be surrounded by restricted area filled with air.
6. Application Interface 6.1 Power Supply Requirements Table3 Power Supply and ON/OFF Control Signal I/O Function Note VCCIO PWR 2.8V power output Can be used to power the level translators. Imax=5mA RESET DI Reset input Active low > 60mS. ON/OFF VBAT DI Switch the module on/off Main Power Supply Low level pulse triggered. PWR 3.5V~4.3V(typical 3.9V) 6.1.1 Power Supply Basic Design Rules VBAT is the main power supply for internal base band and radio PA of the module, in a range of 3.5V-4.
Figure 4 Burst Caused Current Peaks and Voltage Drops Figure 5 Test Circuit and Peak Current Results may vary depending on the ESR of capacitors, and the impedance of power source. A low ESR 1000uF aluminum capacitor for C1 can be selected. As an alternative, a 470uF tantalum capacitor is also suited. In case of Li-Ion cell battery used, 220uF or even 100uF tantalum capacitor may be applicable because of the battery’s low internal impedance and the ability to provide high transient current.
The power source should be able to output an average current greater than 1A. Some small capacitors, with values of 0.1uF, 100pF, 33pF, placed close to the module’s power pin, are very helpful to suppress high frequency disturbances. The voltage range of power supply must never be exceeded. Over-voltage can even destroy the module permanently. Ensure the trace for VBAT to be wide enough, in order to pass the current peaks without significant voltage drops. The width of 2mm is preferable. 6.
Figure 7 Using PMOS for power control Q2 is for eliminating the need for a high enough voltage level of the host GPIO. In case that the GPIO can output a high voltage greater than VDD3V9 - |VGS(th)|, where VGS(th) is the Gate Threshold Voltage, Q2 is not needed. Reference components: Q1: IRML6401 Q2: MMBT3904 C4: 470uF tantalum capacitor rated at 6.3V; or 1000uF aluminum capacitor. It’s strongly recommended to place a TVS diode on VBAT to ground, in order to absorb the power surges subjected. The SMAJ5.
resistance. The value of 10uH, with average current ability>1.2A and low DC resistance, is recommended. Figure 8 Using separated power supply for module Never use a diode to make the drop voltage between a higher input and module power. It will obviously decrease the module performances, or result in unexpected restarts, due to the forward voltage of diode will vary greatly in different temperature and current. 6.1.2.
Figure 9 Turning on /off the module using ON/OFF 6.2.1 Turning on the module While the module is off, drive the ON/OFF pin to ground for at least 600mS (800mS is recommended) and then release, the module will start. An unsolicited message will be sent to host through AT port (“+EIND: 1”), indicating the powering up of the module and the AT commands can respond. It’s recommended to drive the ON/OFF to low before applying the VBAT to module.
Figure 10 Reference circuit for ON/OFF control Reference Components: Q1: MMBT3904, or to use digital transistor with bias resistors built in, like DTC123/114 The combination of R3 and R4, should limit the high voltage of ON/OFF less than 3.0V. Note: If the host itself is not initialized before turning on the module, some abnormal conditions on IO or UART may affect the power on procedure.
6.3 UART 6.3.1 Basic Descriptions of UART Table4 UART Signal I/O Function URXD1 UTXD1 DI DO Serial input of module Serial output of module DTR DI Signal for controlling sleep mode RING DO Ringing output Note UART1 is for AT commands, data sending/receiving, firmware updating, etc. As a DCE device, the module is connected to DTE as shown in Figure 11. Supported baud rates are 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400bps, and the default is 115200.
Figure 12 Interfacing with 3.3V logic levels of MCU If the UART is interfacing with a MCU that has 5V logic levels, general level translators are required, for both inputs and outputs. As shown in Figure 13. Figure 13 Interfacing with 5V logic levels of MCU Reference components: R2: 2K-10K. The higher rate the UART works at, the smaller value used R3: 4.7K-10K. The higher rate the UART works at, the smaller value used Q1: MMBT3904 or MMBT2222. High-speed transistors preferred. Used for 5V logic -> 2.
Note: Avoid sparks and glitches on UART signals while the module is in a turning on procedure. Avoid sending any data to UART during the beginning of 2 seconds after the module being turned on. 6.4 Sleep mode 6.4.1 DTR Generally DTR is used for sleep mode control. For details, see AT commands manual. Based on the setting of the selected mode, pulling DTR low will bring the module into relevant power saving mode.
5) Pull DTR high, the module will exit from sleep mode actively, and furthermore enable the UART. Thus the voice call, received data, or SMS can be processed through UART. After processing finished pull it low again, to take the module back to sleep mode. 6.4.2 RING 1) Once the incoming voice call, the module sends out “ring” message through UART and meanwhile outputs 250mS low pulses at 4S period on RING signal. See Figure 14.
Figure 16a Reference design of SIM interface Pin1=VCC, Pin2=RST, Pin3=CLK, Pin4=GND, Pin5=VPP, Pin6=DATA Figure 16b a sample of SIM card socket Figure 16c the recommended ESD diode array M660 SIM interface is 3V/1.8V compatible. VSIM is for SIM power and can supply a 30mA current. SIM_DATA is internally pulled up with a 5KΩ resistor. External pull-up resistor is not needed. SIM_CLK can work at several frequencies, but at 3.25MHz typically.
The antenna should be installed a long distance away from the SIM card and SIM card traces, especially to the build-in antenna. The PCB traces of SIM should be as short as possible and shielded with GND copper. The ESD diodes or small capacitors should be closed to SIM card. Note: Small capacitors and the junction capacitance of the ESD diode are to avoid the interference from/to antenna, ensuring the correct SIM access and good RF performance. 6.
6.7 Audio Interface Table7 Audio Interface Signal MICP I/O AI Function MIC+ input Note Vpp ≤ 200mV MICN AI MIC- input Vpp ≤ 200mV EAR-L AO Earpiece output L Can drive a 16Ω/32Ω earpiece directly EAR-R AO Earpiece output R Can drive a 16Ω/32Ω earpiece directly For reference audio interface see Figure 18. The peak-peak voltage routed to MIC+/MIC- should not exceed 200mV. AGC circuit is integrated inside the module. Electret microphone is suited.
Figure 19 Reference design for MIC interface Figure 20 Reference design for Ear interface Figure 20 shows a reference design for earpiece interface. A 16Ω/32Ω earpiece can be directly driven by the module. To pass the low frequency audio, use large capacitors for C1 and C2. If an external amplifier is used for driving the speakers, 1uF~4.7uF coupling capacitors should be used to block the DC voltage, as shown in Figure 21. Shenzhen Neoway Technology Co., Ltd.
Figure 21 Using capacitors to couple audio outputs As the description of TDD noise before, the GSM radio frequency is modulated at 217Hz. The 217Hz and its derivative frequency is well within audio band, therefore a TDD noise often affect the audio performance through power and air. Some small capacitors between 27pF-100pF and ferrite beads, placed on the audio path can attenuate TDD noise. For Suppressing the TDD noise, differential audio interface is preferable.
If the trace between the module and connector has to be longer, or built-in antenna is used, a π-type matching circuit should be needed, as shown in Figure 22. The types and values of C1, L1, and L2 should be verified by testing using network analyzer instrument. If the characteristic impedance is well matched, and VSWR requirement is met, just use a 0Ω resistor for C1 and leave L1, L2 un-installed. Avoid any other traces crossing the antenna trace on neighboring layer.
This GND Pad should be well routed to ground Antenna pad should be surrounded by ground Antenna trace should be surrounded by ground which is connected to main ground plane with plenty of via holes. The trace width and the space to ground should be decided by calculating of 50Ω impedance match. Figure 24 Reference layout for antenna interface 7. Mounting the Module onto the Application Board M660 is compatible with industrial standard reflow profile for lead-free SMT process.
8. Package M660 modules are packaged in sealed bags on delivery to guarantee a long shelf life. Package the modules again in case of opening for any reasons. If exposed in air for more than 48 hours at conditions not worse than 30°C/60% RH, a baking procedure should be done before SMT. Or, if the indication card shows humidity greater than 20%, the baking procedure is also required. The baking should last for at least 24 hours at 90℃. 9.
TDMA Time Division Multiple Access UART Universal asynchronous receiver-transmitter Varistor Voltage Dependent Resistor VSWR Voltage Standing Wave Ratio Shenzhen Neoway Technology Co., Ltd.
Warning Statement This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
20cm minimum distance has to be able to be maintained between the antenna and the users for the host this module is integrated into. Under such configuration, the FCC radiation exposure limits set forth for an population/uncontrolled environment can be satisfied. Any changes or modifications not expressly approved by the manufacturer could void the user's authority to operate this equipment.
