Quectel EC21 Series Скачать руководство пользователя страница 31

Страница: 31 / 95

LTE Module Series

EC21 Hardware Design

EC21_Hardware_Design Confidential / Released 30 / 94

The following figure shows the connection between the module and the host.

USB_VBUS

USB_DP

USB_DM

AP_READY

VDD

USB_DP

USB_DM

GPIO

Module

Host

GND

Figure 4: Sleep Mode Application with USB Remote Wakeup



Sending data to EC21 through USB will wake up the module.



When EC21 has URC to report, the module will send remote wake-up signals via USB bus so as to

wake up the host.

3.5.1.3. USB Application with USB Suspend/Resume and RI Function

If the host supports USB suspend/resume, but does not support remote wake-up function, the RI signal is

needed to wake up the host.

There are three preconditions to let the module enter into the sleep mode.



Execute

AT+QSCLK=1

command to enable sleep mode.



Ensure the DTR is held in high level or keep it open.



The host’s USB bus, which is connected with the module’s USB interface, enters into suspended

state.

Quectel

Confidential

Содержание EC21 Series

Страница 1: ...EC21 Hardware Design LTE Module Series Rev EC21_Hardware_Design_V1 4 Date 2017 03 01 www quectel com...

Страница 2: ...ION PROVIDED IS BASED UPON CUSTOMERS REQUIREMENTS QUECTEL MAKES EVERY EFFORT TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAI...

Страница 3: ...d main UART supports baud rate in Chapter 3 11 7 Added notes for ADC interface in Chapter 3 13 8 Updated GNSS Performance in Table 21 9 Updated operating frequencies of module in Table 23 10 Added cur...

Страница 4: ...4 Added BT interface in Chapter 3 18 2 5 Updated reference circuit of wireless connectivity interfaces with FC20 module in Figure 29 6 Updated GNSS performance in Table 24 7 Updated module operating f...

Страница 5: ...n with USB Remote Wakeup Function 29 3 5 1 3 USB Application with USB Suspend Resume and RI Function 30 3 5 1 4 USB Application without USB Suspend Function 31 3 5 2 Airplane Mode 32 3 6 Power Supply...

Страница 6: ...5 3 Antenna Installation 65 5 3 1 Antenna Requirement 65 5 3 2 Recommended RF Connector for Antenna Installation 66 6 Electrical Reliability and Radio Characteristics 68 6 1 Absolute Maximum Ratings...

Страница 7: ...49 TABLE 18 WORKING STATE OF NETWORK CONNECTION STATUS ACTIVITY INDICATOR 49 TABLE 19 PIN DEFINITION OF STATUS 50 TABLE 20 BEHAVIOR OF THE RI 51 TABLE 21 PIN DEFINITION OF THE SGMII INTERFACE 52 TABL...

Страница 8: ...ITY 78 TABLE 46 EC21 KL CONDUCTED RF RECEIVING SENSITIVITY 78 TABLE 47 EC21 CT CONDUCTED RF RECEIVING SENSITIVITY 78 TABLE 48 EC21 J CONDUCTED RF RECEIVING SENSITIVITY 79 TABLE 49 EC21 AUV CONDUCTED R...

Страница 9: ...RE 18 REFERENCE CIRCUIT OF USIM CARD INTERFACE WITH A 6 PIN USIM CARD CONNECTOR 40 FIGURE 19 REFERENCE CIRCUIT OF USB APPLICATION 42 FIGURE 20 REFERENCE CIRCUIT WITH TRANSLATOR CHIP 44 FIGURE 21 REFER...

Страница 10: ...ECTORS 66 FIGURE 39 SPACE FACTOR OF MATED CONNECTOR UNIT MM 67 FIGURE 40 MODULE TOP AND SIDE DIMENSIONS 81 FIGURE 41 MODULE BOTTOM DIMENSIONS BOTTOM VIEW 82 FIGURE 42 RECOMMENDED FOOTPRINT TOP VIEW 83...

Страница 11: ...e and hardware interface which are connected with your application This document can help you quickly understand module interface specifications electrical and mechanical details as well as other rela...

Страница 12: ...rding the aircraft if your device offers an Airplane Mode which must be enabled prior to boarding an aircraft Switch off your wireless device when in hospitals clinics or other health care facilities...

Страница 13: ...L You can choose a dedicated type based on the region or operator The following table shows the frequency bands of EC21 series module Table 1 Frequency Bands of EC21 Series Module Modules2 LTE Bands 3...

Страница 14: ...EC21 is an SMD type module which can be embedded into applications through its 144 pin pads including 80 LCC signal pads and 64 other pads 2 2 Key Features The following table describes the detailed...

Страница 15: ...and CHAP Challenge Handshake Authentication Protocol protocols which are usually used for PPP connections SMS Text and PDU mode Point to point MO and MT SMS cell broadcast SMS storage ME by default U...

Страница 16: ...etwork connectivity status Antenna Interface Including main antenna interface ANT_MAIN Rx diversity antenna interface ANT_DIV and GNSS antenna interface ANT_GNSS Physical Characteristics Size 32 0 0 1...

Страница 17: ...aseband PMIC Transceiver NAND DDR2 SDRAM PA Switch LNA Switch ANT_MAIN ANT_DIV ANT_GNSS VBAT_BB VBAT_RF APT PWRKEY ADCs VDD_EXT USB USIM PCM UART I2C RESET_N 19 2M XO STATUS GPIOs SAW Control IQ Contr...

Страница 18: ...lus 64 pin ground pads and reserved pads that can be connected to cellular application platform Sub interfaces included in these pads are described in detail in the following chapters Power supply USI...

Страница 19: ...C_SDA I2C_SCL BT_CTS ADC0 GND GND GND 73 74 75 76 77 78 79 80 81 82 83 84 100 101 102 106 107 111 112 103 104 109 105 110 89 94 98 88 93 97 86 91 96 85 90 95 99 87 92 108 113 RESERVED RESERVED 117 126...

Страница 20: ...ion of EC21 module Table 3 I O Parameters Definition Type Description IO Bidirectional DI Digital input DO Digital output PI Power input PO Power output AI Analog input AO Analog output OD Open drain...

Страница 21: ...STATUS 61 OD Indicate the module operating status The drive current should be less than 0 9mA Require external pull up If unused keep it open NET_MODE 5 DO Indicate the module network registration mo...

Страница 22: ...tically USIM_DATA 15 IO Data signal of USIM card For 1 8V USIM VILmax 0 6V VIHmin 1 2V VOLmax 0 45V VOHmin 1 35V For 3 0V USIM VILmax 1 0V VIHmin 1 95V VOLmax 0 45V VOHmin 2 55V USIM_CLK 16 DO Clock s...

Страница 23: ...ull up by default Low level wakes up the module If unused keep it open TXD 67 DO Transmit data VOLmax 0 45V VOHmin 1 35V 1 8V power domain If unused keep it open RXD 68 DI Receive data VILmin 0 3V VIL...

Страница 24: ...d keep it open PCM_CLK 27 IO PCM clock VOLmax 0 45V VOHmin 1 35V VILmin 0 3V VILmax 0 6V VIHmin 1 2V VIHmax 2 0V 1 8V power domain In master mode it is an output signal In slave mode it is an input si...

Страница 25: ...ax 0 45V VOHmin 1 4V For 2 85V VOLmax 0 35V VOHmin 2 14V 1 8V 2 85V power domain If unused keep it open USIM2_VDD 128 PO SGMII MDIO pull up power source Configurable power source 1 8V 2 85V power doma...

Страница 26: ...nused keep it open SDC1_CLK 133 DO SDIO clock VOLmax 0 45V VOHmin 1 35V 1 8V power domain If unused keep it open SDC1_CMD 134 DO SDIO command VOLmax 0 45V VOHmin 1 35V 1 8V power domain If unused keep...

Страница 27: ...TS 40 DO BT UART clear to send VOLmax 0 45V VOHmin 1 35V 1 8V power domain If unused keep it open BT_EN 139 DO BT function control via FC20 module VOLmax 0 45V VOHmin 1 35V 1 8V power domain If unused...

Страница 28: ...d keep it open Other Interface Pins Pin Name Pin No I O Description DC Characteristics Comment USB_BOOT 115 DI Force the module to boot from USB port VILmin 0 3V VILmax 0 6V VIHmin 1 2V VIHmax 2 0V 1...

Страница 29: ...n can set the module to airplane mode In this case RF function will be invalid Sleep Mode In this mode the current consumption of the module will be reduced to the minimal level During this mode the m...

Страница 30: ...r AP_READY will detect the sleep state of the host can be configured to high level or low level detection Please refer to AT QCFG apready command for details AT QCFG apready command is under developme...

Страница 31: ...ort the module will send remote wake up signals via USB bus so as to wake up the host 3 5 1 3 USB Application with USB Suspend Resume and RI Function If the host supports USB suspend resume but does n...

Страница 32: ...p the host 3 5 1 4 USB Application without USB Suspend Function If the host does not support USB suspend function you should disconnect USB_VBUS with additional control circuit to let the module enter...

Страница 33: ...module enter into airplane mode Software AT CFUN command provides the choice of the functionality level AT CFUN 0 Minimum functionality mode both USIM and RF functions are disabled AT CFUN 1 Full func...

Страница 34: ...urst Transmission To decrease voltage drop a bypass capacitor of about 100 F with low ESR should be used and a multi layer ceramic chip MLCC capacitor array should also be used to provide the low ESR...

Страница 35: ...t you should use an LDO to supply power for the module If there is a big voltage difference between the input source and the desired output VBAT a buck converter is preferred to be used as the power s...

Страница 36: ...Qualcomm chipset When EC21 is in power down mode it can be turned on to normal mode by driving the PWRKEY pin to a low level for at least 100ms It is recommended to use an open drain collector driver...

Страница 37: ...troke The turn on scenario is illustrated in the following figure VIL 0 5V VIH 1 3V VBAT PWRKEY 100ms RESET_N STATUS OD Inactive Active UART NOTE Inactive Active USB 2 5s 12s 13s Figure 12 Timing of T...

Страница 38: ...r the PWRKEY is released The power down scenario is illustrated in the following figure VBAT PWRKEY 29 5s 650ms RUNNING Power down procedure OFF Module Status STATUS OD Figure 13 Timing of Turning off...

Страница 39: ...n Description Pin Name Pin No Description DC Characteristics Comment RESET_N 20 Reset the module VIHmax 2 1V VIHmin 1 3V VILmax 0 5V The recommended circuit is similar to the PWRKEY control circuit An...

Страница 40: ...and RESET_N pins 3 9 USIM Card Interface The USIM card interface circuitry meets ETSI and IMT 2000 SIM interface requirements Both 1 8V and 3 0V USIM cards are supported Table 9 Pin Definition of the...

Страница 41: ...ESENCE 22R 22R 22R VDD_EXT 51K 100nF USIM Card Connector GND GND 33pF 33pF 33pF VCC RST CLK IO VPP GND GND USIM_VDD 15K Figure 17 Reference Circuit of USIM Card Interface with an 8 Pin USIM Card Conne...

Страница 42: ...e 33pF capacitors are used for filtering interference of GSM900 Please note that the USIM peripheral circuit should be close to the USIM card connector The pull up resistor on USIM_DATA line can impro...

Страница 43: ...sible In order to ensure the USB interface design corresponding with the USB 2 0 specification please comply with the following principles It is important to route the USB signal traces as differentia...

Страница 44: ...on The debug UART interface supports 115200bps baud rate It is used for Linux console and log output The following tables show the pin definition of the main UART interface Table 11 Pin Definition of...

Страница 45: ...nt is recommended The following figure shows a reference design VCCA VCCB OE A1 A2 A3 A4 A5 A6 A7 A8 GND B1 B2 B3 B4 B5 B6 B7 B8 VDD_EXT RI DCD RTS RXD DTR CTS TXD 51K 51K 0 1uF 0 1uF RI_MCU DCD_MCU R...

Страница 46: ...chronization works as master only In primary mode the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising edge The PCM_SYNC falling edge represents the MSB In this mode PC...

Страница 47: ...25us MSB 1 2 16 15 LSB Figure 23 Auxiliary Mode Timing The following table shows the pin definition of PCM and I2C interfaces which can be applied on audio codec design Table 14 Pin Definition of PCM...

Страница 48: ...t with 2048kHz PCM_CLK and 8kHz PCM_SYNC Please refer to document 2 about AT QDAI command for details The following figure shows a reference design of PCM interface with external codec IC PCM_IN PCM_O...

Страница 49: ...d be surrounded by ground Table 15 Pin Definition of the ADC Pin Name Pin No Description ADC0 45 General purpose analog to digital converter ADC1 44 General purpose analog to digital converter The fol...

Страница 50: ...Comment NET_MODE1 5 DO Indicate the module s network registration status 1 8V power domain NET_STATUS 6 DO Indicate the module s network activity status 1 means that this pin cannot be pulled up befo...

Страница 51: ...cation circuit shown below When the module is turned on normally the STATUS will present the low state Otherwise the STATUS will present high impedance state Table 19 Pin Definition of STATUS Pin Name...

Страница 52: ...e Idle RI keeps in high level URC RI outputs 120ms low pulse when new URC returns The RI behavior can be changed by AT QCFG urc ri ring command Please refer to document 2 for details 3 17 SGMII Interf...

Страница 53: ...85V power domain External pull up power source for SGMII MDIO pins SGMII Signal Part SGMII_TX_M 123 AO SGMII transmission minus Connect with a 0 1uF capacitor close to the PHY side SGMII_TX_P 124 AO...

Страница 54: ...3 Application In order to enhance the reliability and availability in your application please follow the criteria below in the Ethernet PHY circuit design Keep SGMII data and control signals away from...

Страница 55: ...C1_DATA0 132 IO SDIO data bus D0 1 8V power domain SDC1_CLK 133 DO SDIO clock 1 8V power domain SDC1_CMD 134 IO SDIO command 1 8V power domain WLAN_EN 136 DO WLAN function control via FC20 module Acti...

Страница 56: ...on EC21 module and BT function on FC20 module The following figure shows a reference design of wireless connectivity interfaces with Quectel FC20 module Module SDC1_DATA3 SDC1_DATA2 SDC1_DATA1 SDC1_DA...

Страница 57: ...ng principles It is important to route the SDIO signal traces with total grounding The impedance of SDIO signal trace is 50 ohm 10 Protect other sensitive signals circuits RF analog signals etc from S...

Страница 58: ...USB port for firmware upgrade Table 23 Pin Definition of USB_BOOT Interface Pin Name Pin No I O Description Comment USB_BOOT 115 DI Force the module to boot from USB port 1 8V power domain Active hig...

Страница 59: ...face by default By default EC21 GNSS engine is switched off It has to be switched on via AT command For more details about GNSS engine technology and configurations please refer to document 3 4 2 GNSS...

Страница 60: ...nal value at the antenna port on which the module fixes position within 3 minutes after executing cold start command 4 3 Layout Guidelines The following layout guidelines should be taken into account...

Страница 61: ...5 1 1 Pin Definition The pin definition of main antenna and Rx diversity antenna interfaces is shown below Table 25 Pin Definition of the RF Antenna Pin Name Pin No I O Description Comment ANT_MAIN 49...

Страница 62: ...ANT_DIV antenna pads is shown as below It should reserve a type matching circuit for better RF performance The capacitors are not mounted by default ANT_MAIN R1 0R C1 Module Main antenna NM C2 NM R2 0...

Страница 63: ...the materials dielectric constant the distance between signal layer and reference ground H and the clearance between RF trace and ground S Microstrip line or coplanar waveguide line is typically used...

Страница 64: ...acent to RF pins should not be hot welded and should be fully connected to ground The distance between the RF pins and the RF connector should be as short as possible and all the right angle traces sh...

Страница 65: ...S antenna 50 ohm impedance Table 28 GNSS Frequency Type Frequency Unit GPS Galileo QZSS 1575 42 1 023 MHz GLONASS 1597 5 1605 8 MHz BeiDou 1561 098 2 046 MHz A reference design of GNSS antenna is show...

Страница 66: ...arization RHCP or linear VSWR 2 Typ Passive antenna gain 0dBi Active antenna noise figure 1 5dB Active antenna gain 2dBi Active antenna embedded LNA gain 20dB Typ Active antenna total gain 18dBi Typ G...

Страница 67: ...allation If RF connector is used for antenna connection it is recommended to use UF L R SMT connector provided by HIROSE Figure 37 Dimensions of the UF L R SMT Connector Unit mm U FL LP serial connect...

Страница 68: ...EC21_Hardware_Design Confidential Released 67 94 The following figure describes the space factor of mated connector Figure 39 Space Factor of Mated Connector Unit mm For more details please visit htt...

Страница 69: ...sted in the following table Table 30 Absolute Maximum Ratings Parameter Min Max Unit VBAT_RF VBAT_BB 0 3 4 7 V USB_VBUS 0 3 5 5 V Peak Current of VBAT_BB 0 0 8 A Peak Current of VBAT_RF 0 1 8 A Voltag...

Страница 70: ...erature Parameter Min Typ Max Unit Operation Temperature Range1 35 25 75 C Extended Temperature Range2 40 85 C 1 1 Within operation temperature range the module is 3GPP compliant 2 2 Within extended t...

Страница 71: ...d 2 2 mA LTE FDD PF 128 USB disconnected 2 2 mA Idle state GNSS OFF WCDMA PF 64 USB disconnected 21 6 mA WCDMA PF 64 USB connected 31 6 mA LTE FDD PF 64 USB disconnected 23 7 mA LTE FDD PF 64 USB conn...

Страница 72: ...LTE FDD PF 128 USB disconnected 2 4 mA Idle state WCDMA PF 64 USB disconnected 22 0 mA WCDMA PF 64 USB connected 32 0 mA LTE FDD PF 64 USB disconnected 23 6 mA LTE FDD PF 64 USB connected 33 6 mA WCDM...

Страница 73: ...ected TBD mA WCDMA PF 64 USB connected TBD mA LTE FDD PF 64 USB disconnected TBD mA LTE FDD PF 64 USB connected TBD mA GPRS data transfer GNSS OFF GSM900 4DL 1UL 32 3dBm 220 mA GSM900 3DL 2UL 32 18dBm...

Страница 74: ...B5 23 4dBm 786 mA LTE FDD B7 23 86dBm 887 mA LTE FDD B8 23 5dBm 675 mA LTE FDD B20 23 57dBm 770 mA GSM voice call GSM900 PCL 5 32 8dBm 336 mA PCS1800 PCL 0 29 3dBm 291 mA WCDMA voice call WCDMA B1 23...

Страница 75: ...5 mA LTE FDD PF 128 USB disconnected 2 0 mA Idle state GNSS OFF LTE FDD PF 64 USB disconnected 22 0 mA LTE FDD PF 64 USB connected 32 0 mA LTE data transfer GNSS OFF LTE FDD B4 22 79dBm 752 0 mA LTE F...

Страница 76: ...data transfer GNSS OFF LTE FDD B1 23 12dBm 721 0 mA LTE FDD B3 23 04dBm 734 0 mA LTE FDD B5 23 16dBm 669 0 mA LTE FDD B8 23 21dBm 698 0 mA LTE FDD B28 23 57dBm 790 0 mA WCDMA voice call WCDMA B1 22 7...

Страница 77: ...B 50dBm LTE FDD bands 23dBm 2dB 44dBm LTE TDD bands 23dBm 2dB 44dBm In GPRS 4 slots TX mode the maximum output power is reduced by 3 0dB The design conforms to the GSM specification as described in Ch...

Страница 78: ...d RF Receiving Sensitivity Frequency Primary Diversity SIMO 3GPP SIMO WCDMA B2 110 0dBm 104 7dBm WCDMA B4 110 0dBm 106 7dBm WCDMA B5 110 5dBm 104 7dBm LTE FDD B2 10M 98 0dBm 98 0dBm 101 0dBm 94 3dBm L...

Страница 79: ...0dBm 96 0dBm 100 0dBm 93 3dBm LTE FDD B7 10M 97 0dBm 95 0dBm 98 5dBm 94 3dBm LTE FDD B28 10M 97 0dBm 99 0dBm 102 0dBm 94 8dBm Table 46 EC21 KL Conducted RF Receiving Sensitivity Frequency Primary Dive...

Страница 80: ...97 5dBm 98 7dBm 100 2dBm 96 3dBm LTE FDD B3 10M 96 5dBm 97 1dBm 100 5dBm 93 3dBm LTE FDD B8 10M 98 4dBm 99 0dBm 101 2dBm 93 3dBm LTE FDD B18 10M 99 5dBm 99 0dBm 101 7dBm 96 3dBm LTE FDD B19 10M 99 2dB...

Страница 81: ...ply to ESD sensitive components Proper ESD handling and packaging procedures must be applied throughout the processing handling and operation of any application that incorporates the module The follow...

Страница 82: ...ial Released 81 94 7 Mechanical Dimensions This chapter describes the mechanical dimensions of the module All dimensions are measured in mm 7 1 Mechanical Dimensions of the Module 32 0 15 29 0 15 0 8...

Страница 83: ...dential Released 82 94 1 30 1 30 1 10 1 10 3 85 2 0 3 0 3 5 0 8 1 5 3 2 3 4 3 2 3 4 3 2 6 75 3 45 1 6 2 49 2 4 2 15 4 4 1 7 4 88 1 8 1 8 1 15 1 05 29 0 1 90 3 5 1 9 32 0 3 35 2 8 4 8 0 82 5 96 2 0 Fig...

Страница 84: ...0 1 80 1 90 1 30 3 20 3 40 3 20 3 40 3 20 3 00 0 80 32 0 3 40 2 50 1 00 1 80 0 50 0 50 2 80 0 50 0 50 3 40 3 45 3 00 2 00 1 10 1 10 2 00 2 00 3 50 Figure 42 Recommended Footprint Top View 1 The keepou...

Страница 85: ...eased 84 94 7 3 Design Effect Drawings of the Module Figure 43 Top View of the Module Figure 44 Bottom View of the Module These are design effect drawings of EC21 module For more accurate pictures ple...

Страница 86: ...vironment of 30 C 60 RH Stored at 10 RH 3 Devices require baking before mounting if any circumstances below occurs When the ambient temperature is 23 C 5 C and the humidity indicator card shows the hu...

Страница 87: ...ture is from 235 to 245 C for SnAg3 0Cu0 5 alloy The absolute maximum reflow temperature is 260 C To avoid damage to the module caused by repeated heating it is suggested that the module should be mou...

Страница 88: ...and contains 250pcs modules The figure below shows the packaging details measured in mm 30 3 0 15 29 3 0 15 30 3 0 15 32 5 0 15 33 5 0 15 0 35 0 05 4 2 0 15 3 1 0 15 32 5 0 15 33 5 0 15 4 00 0 1 2 00...

Страница 89: ...nds Manual 4 Quectel_Module_Secondary_SMT_User_Guide Module Secondary SMT User Guide 5 Quectel_EC21_Reference_Design EC21 Reference Design 6 Quectel_RF_Layout_Application_Note RF Layout Application No...

Страница 90: ...tion Satellite System GMSK Gaussian Minimum Shift Keying GNSS Global Navigation Satellite System GPS Global Positioning System GSM Global System for Mobile Communications HR Half Rate HSPA High Speed...

Страница 91: ...it Media Independent Interface SIM Subscriber Identification Module SIMO Single Input Multiple Output SMS Short Message Service TDD Time Division Duplexing TDMA Time Division Multiple Access TD SCDMA...

Страница 92: ...age Value VImax Absolute Maximum Input Voltage Value VImin Absolute Minimum Input Voltage Value VOHmax Maximum Output High Level Voltage Value VOHmin Minimum Output High Level Voltage Value VOLmax Max...

Страница 93: ...mes Table 53 Description of Different Coding Schemes Scheme CS 1 CS 2 CS 3 CS 4 Code Rate 1 2 2 3 3 4 1 USF 3 3 3 3 Pre coded USF 3 6 6 12 Radio Block excl USF and BCS 181 268 312 428 BCS 40 16 16 16...

Страница 94: ...or 2 2 the first number indicates the amount of downlink timeslots while the second number indicates the amount of uplink timeslots The active slots determine the total number of slots the GPRS devic...

Страница 95: ...K 13 4kbps 26 8kbps 53 6kbps CS 3 GMSK 15 6kbps 31 2kbps 62 4kbps CS 4 GMSK 21 4kbps 42 8kbps 85 6kbps MCS 1 GMSK C 8 80kbps 17 60kbps 35 20kbps MCS 2 GMSK B 11 2kbps 22 4kbps 44 8kbps MCS 3 GMSK A 14...

Результаты поиска

Содержание EC21 Series

Отзывы:

Бренды по названию

Популярные бренды

Quectel EC21 Series, Проектирование аппаратного обеспечения

Результаты поиска

Содержание EC21 Series

Отзывы:

Бренды по названию

Популярные бренды