SARA-R4 series Multi-band LTE-M / NB-IoT / EGPRS modules System integration manual SARA-R4 Abstract This document describes the features and the integration of the size-optimized SARA-R4 series cellular modules. These modules are a complete, cost efficient, performance optimized, multi-mode and multi band LTE-M / NB-IoT / EGPRS solution in the compact SARA form factor. UBX-16029218 - R20 C1-Public www.u-blox.
SARA-R4 series - System integration manual Document information Title SARA-R4 series Subtitle Multi-band LTE-M / NB-IoT / EGPRS modules Document type System integration manual Document number UBX-16029218 Revision and date R20 Disclosure restriction C1-Public 11-Mar-2021 Product status Corresponding content status Functional sample Draft For functional testing. Revised and supplementary data will be published later. In development / Prototype Objective specification Target values.
SARA-R4 series - System integration manual This document applies to the following products: Product name Type number Modem version SARA-R410M SARA-R410M-01B-00 L0.0.00.00.02.03 SARA-R410M-02B-00 L0.0.00.00.05.06 A02.00 UBX-18010263 Obsolete L0.0.00.00.05.06 A02.01 UBX-18070443 Obsolete SARA-R410M-02B-01 L0.0.00.00.05.08 A02.04 UBX-19041392 Mass production SARA-R410M-02B-02 L0.0.00.00.05.11 A.02.16 UBX-20033274 Mass production SARA-R410M-02B-03 L0.0.00.00.05.12 A.02.
SARA-R4 series - System integration manual Contents Document information ................................................................................................................................ 2 Contents .......................................................................................................................................................... 4 1 System description .......................................................................................................................
SARA-R4 series - System integration manual 2.4.1 General guidelines for antenna interfaces ..................................................................................62 2.4.2 Cellular antenna RF interface (ANT) .............................................................................................66 2.4.3 GNSS antenna RF interface (ANT_GNSS) ...................................................................................69 2.4.4 Cellular and GNSS RF coexistence .......................
SARA-R4 series - System integration manual 3.3.8 Rework ............................................................................................................................................. 106 3.3.9 Conformal coating ......................................................................................................................... 106 3.3.10 Casting .............................................................................................................................................
SARA-R4 series - System integration manual 1 System description 1.1 Overview The SARA-R4 series modules are a multi-band LTE-M / NB-IoT / EGPRS multi-mode solution in the miniature SARA LGA form factor (26.0 x 16.0 mm, 96-pin). They allow an easy integration into compact designs and a seamless drop-in migration from other u-blox cellular module families.
SARA-R4 series - System integration manual SARA-R410M-02B 13 M1 Multi region 13 M1 NB1 Automotive Professional Standard Antenna and SIM detection Grade Jamming detection Last gasp MQTT / MQTT-SN u-blox Firmware update Over the Air (uFOTA) device management LwM2M FW update via serial DTLS Embedded HTTPS, FTPS, TLS Embedded TCP/UDP stack Ultra-low power consumption in PSM Features Root of trust: secure element Security services I2S audio interface DDC (I2C) GPIOs SDIO Interfaces SPI
SARA-R4 series - System integration manual SARA-R4 series modules include the following variants / product versions: • • • • • • SARA-R410M-01B LTE Cat M1 module, mainly designed for operation in LTE bands 2, 4, 5, 12 SARA-R410M-02B LTE Cat M1 / NB1 module, mainly designed for operation in LTE bands 2, 3, 4, 5, 8, 12, 13, 20, 25, 28 SARA-R410M-52B LTE Cat M1 module, mainly designed for operation in LTE bands 2, 4, 5, 12, 13 Secure Cloud SARA-R410M-63B LTE Cat M1 module, mainly designed for operation in LTE
SARA-R4 series - System integration manual Item SARA-R410M SARA-R412M SARA-R422 /-R422S /-R422M8S Protocol stack 3GPP Release 13 3GPP Release 13 3GPP Release 14 RAT LTE Cat M1 LTE Cat NB1 1, 3, 4, 6 LTE Cat M1 LTE Cat NB1 2G GPRS / EGPRS LTE Cat M1 LTE Cat NB1 2G GPRS / EGPRS LTE FDD bands Band 1 (2100 MHz) 1, 4, 7 Band 2 (1900 MHz) 6, 7 Band 3 (1800 MHz) 1, 4 Band 4 (1700 MHz) 6, 7 Band 5 (850 MHz) Band 8 (900 MHz) 1, 4 Band 12 (700 MHz) 6, 7 Band 13 (750 MHz) 1, 6, 7 Band 18 (850 MHz) 1, 3, 4
SARA-R4 series - System integration manual 1.2 Architecture Figure 1 summarizes the internal architecture of SARA-R410M and SARA-R412M modules. Filters ANT PAs RF transceiver Switch Filters SIM SIM card detection UART USB Cellular BaseBand Processor Memory 19.2 MHz Reset SDIO SPI / Digital audio GPIOs VCC (Supply) V_INT DDC (I2C) Antenna detection Power Management Power-on Figure 1: SARA-R410M and SARA-R412M modules simplified block diagram ☞ The SARA-R410M-01B modules, i.e.
SARA-R4 series - System integration manual Figure 2 summarizes the internal architecture of SARA-R422 and SARA-R422S modules. Filters ANT PAs RF transceiver Switch Filters SIM SIM card detection UARTs Cellular BaseBand Processor USB DDC (I2C) Digital audio Memory 19.2 MHz GPIOs Antenna detection VCC (Supply) V_INT Power Management Power-control Figure 2: SARA-R422 and SARA-R422S modules simplified block diagram Figure 3 summarizes the internal architecture of SARA-R422M8S modules.
SARA-R4 series - System integration manual SARA-R4 series modules internally consist of the following sections described herein with more details than the simplified block diagrams of Figure 1, Figure 2 and Figure 3.
SARA-R4 series - System integration manual 1.3 Pin-out Table 3 lists the pin-out of the SARA-R4 series modules, with pins grouped by function. Function Pin Name Pin No Power VCC System Antenna I/O Description Remarks 51,52,53 I Module supply input VCC supply circuit affects the RF performance and compliance of the device integrating the module with applicable required certification schemes. See section 1.5.1 for functional description / requirements. See section 2.2.
SARA-R4 series - System integration manual Function Pin Name Pin No I/O Description SIM VSIM 41 O SIM supply output Supply output for external SIM / UICC. See section 1.8 for functional description. See section 2.5 for external circuit design-in. SIM_IO 39 I/O SIM data Data input/output for external SIM / UICC. Internal 4.7 k pull-up to VSIM. See section 1.8 for functional description. See section 2.5 for external circuit design-in.
SARA-R4 series - System integration manual Function Pin Name USB SPI 15 16 Pin No I/O Description Remarks VUSB_DET 17 I USB detect input VBUS (5 V typ.) sense input pin to enable the USB interface. Test-Point for diagnostic / FW update strongly recommended. See section 1.9.2 for functional description. See section 2.6.2 for external circuit design-in. USB_5V016 17 I USB detect input VBUS (5 V typ.) sense input pin to enable the USB interface.
SARA-R4 series - System integration manual Function Pin Name SDIO DDC Audio 17 18 Pin No I/O Description Remarks 17 SDIO_D0 47 I/O SDIO serial data [0] SDIO interface is not supported by current product versions. See section 1.9.4 for functional description. See section 2.6.4 for external circuit design-in. SDIO_D117 49 I/O SDIO serial data [1] SDIO interface is not supported by current product versions. See section 1.9.4 for functional description. See section 2.6.
SARA-R4 series - System integration manual Function Pin Name Pin No I/O Description Remarks GPIO GPIO1 16 I/O GPIO 1.8 V GPIO with alternatively configurable functions. See section 1.11 for functional description. See section 2.8 for external circuit design-in. GPIO2 23 I/O GPIO 1.8 V GPIO with alternatively configurable functions. See section 1.11 for functional description. See section 2.8 for external circuit design-in. GPIO3 24 I/O GPIO 1.
SARA-R4 series - System integration manual 1.4 Operating modes SARA-R4 series modules have several operating modes. The operating modes are defined in Table 4 and described in detail in Table 5, providing general guidelines for operation. General status Operating mode Power-down Not-powered mode VCC supply not present or below operating range: module is switched off. Power-off mode Normal Operation Deep-sleep mode Definition VCC supply within operating range and module is switched off.
SARA-R4 series - System integration manual Mode Description Transition between operating modes Idle Module is switched on with application interfaces temporarily disabled: the module is temporarily not ready to communicate with an external device by means of the application interfaces as configured to reduce the current consumption (see section 1.5.1.5).
SARA-R4 series - System integration manual The initial operating mode of SARA-R4 series modules is the one with VCC supply not present or below the operating range: the modules are switched off in not-powered mode. Once a valid VCC supply is applied to the SARA-R4 series modules, they remain switched off in the power-off mode. Then the proper toggling of the PWR_ON / PWR_CTRL input line is necessary to trigger the switch-on routine of the modules that subsequently enter the active mode.
SARA-R4 series - System integration manual 1.5 Supply interfaces 1.5.1 Module supply input (VCC) The modules must be supplied via the three VCC pins that represent the module power supply input. Voltage must be stable, because during operation, the current drawn by the SARA-R4 series modules through the VCC pins can vary by several orders of magnitude, depending on the operating mode and state (as described in sections 1.5.1.2, 1.5.1.3, 1.5.1.4 and 1.5.1.6).
SARA-R4 series - System integration manual 1.5.1.1 VCC supply requirements Table 6 summarizes the requirements for the VCC modules supply. See section 2.2.1 for suggestions to correctly design a VCC supply circuit compliant with the requirements listed in Table 6. ⚠ The supply circuit affects the RF compliance of the device integrating SARA-R4 series modules with applicable required certification schemes as well as antenna circuit design.
SARA-R4 series - System integration manual 1.5.1.2 VCC current consumption in LTE connected mode During an LTE connection, the SARA-R4 series modules transmit and receive in half duplex mode. The current consumption depends on output RF power, which is always regulated by the network (the current base station) sending power control commands to the module. These power control commands are logically divided into a slot of 0.
SARA-R4 series - System integration manual Figure 8 shows an example of the module current consumption profile versus time in 2G single-slot. Current [A] 2.0 1900 mA 1.5 Peak current depends on TX power and actual antenna load 1.0 0.5 60-120 mA 0.0 RX slot 200 mA 60-120 mA 10-40 mA unused unused slot slot TX slot unused unused MON unused slot slot slot slot RX slot unused unused slot slot GSM frame 4.
SARA-R4 series - System integration manual Figure 10 illustrates the current consumption profiles in GPRS connected mode, in 850 or 900 MHz bands, with 4 slots used to transmit and 1 slot used to receive, as for the GPRS multi-slot class 12. Current [A] 1600 mA 1.5 Peak current depends on TX power and actual antenna load 1.0 0.5 200mA 60-120mA 0.0 60-120mA 10-40mA RX slot unused slot TX slot TX slot TX slot TX slot GSM frame 4.
SARA-R4 series - System integration manual 1.5.1.5 VCC current consumption in low power idle mode The low power idle mode configuration is by default disabled, but it can be enabled using the +UPSV AT command (see the SARA-R4 series AT commands manual [2]).
SARA-R4 series - System integration manual Figure 13 illustrates a typical example of the module current consumption profile when the module is in active mode. In such case, the module is registered with the network and, while active mode is maintained, the receiver is periodically activated to monitor the paging channel for paging block reception. Detailed current consumption values can be found in the SARA-R4 series data sheet [1].
SARA-R4 series - System integration manual 1.6 System function interfaces 1.6.1 Module power-on When the SARA-R4 series modules are in the not-powered mode (i.e. the VCC module supply is not applied), they can be switched on as follows: • Rising edge on the VCC input pins to a valid voltage level, and then a low logic level needs to be set at the PWR_ON / PWR_CTRL input pin for a valid time. When the SARA-R4 series modules are in the power-off mode (i.e.
SARA-R4 series - System integration manual 1.6.2 Module power-off SARA-R4 series modules can be gracefully switched off by: • • AT+CPWROFF command (see SARA-R4 series AT commands manual [2]). Low pulse on the PWR_ON / PWR_CTRL pin for a valid time period (for detailed characteristics see the SARA-R4 series data sheet [1]). These events listed above trigger the storage of the current parameter settings in the non-volatile memory of the module, and a clean network detach procedure.
SARA-R4 series - System integration manual Figure 15 and Figure 16 describe the SARA-R4 series modules switch-off sequence started by means of the AT+CPWROFF command and by means of the PWR_ON / PWR_CTRL input pin respectively, allowing storage of current parameter settings in the module’s non-volatile memory and a clean network detach, with the following phases: • • • • When the +CPWROFF AT command is sent, or when a low pulse with appropriate time duration (see the SARA-R4 series data sheet [1]) is appl
SARA-R4 series - System integration manual 1.6.3 Module reset SARA-R4 series modules can be cleanly reset (rebooted) by: • +CFUN AT command (see the SARA-R4 series AT commands manual [2]). In the case above an “internal” or “software” reset of the module is executed: the current parameter settings are saved in the module’s non-volatile memory and a clean network detach is performed.
SARA-R4 series - System integration manual 1.7 Antenna interfaces 1.7.1 Cellular antenna RF interface (ANT) SARA-R4 series modules provide an RF interface for connecting the external cellular antenna. The ANT pin represents the primary RF input/output for transmission and reception of cellular RF signals. The ANT pin has a nominal characteristic impedance of 50 and must be connected to the cellular Tx / Rx antenna system through a 50 transmission line to allow clear RF transmission and reception. 1.
SARA-R4 series - System integration manual 1.7.2 GNSS antenna RF interface (ANT_GNSS) ☞ ☞ The GNSS antenna RF interface is supported by SARA-R422M8S modules only. For additional information and guidelines regarding the GNSS system, see the u-blox SARA-R4 / SARA-R5 positioning implementation application note [20]. SARA-R422M8S modules provide an RF interface for connecting the external GNSS antenna. The ANT_GNSS pin represents the RF input reception of GNSS RF signals.
SARA-R4 series - System integration manual 1.7.3 Antenna detection interface (ANT_DET) The antenna detection is based on ADC measurement. The ANT_DET pin is an Analog to Digital Converter (ADC) provided to sense the antenna presence. The antenna detection function provided by ANT_DET pin is an optional feature that can be implemented if the application requires it. The antenna detection is forced by the +UANTR AT command. See the SARA-R4 series AT commands manual [2] for more details on this feature.
SARA-R4 series - System integration manual 1.9 Data communication interfaces SARA-R4 series modules provide the following serial communication interfaces: • • • • • UART interfaces: asynchronous serial interface supporting AT commands, data communication, GNSS tunneling, FW update by means of FOAT. See section 1.9.1. USB interface: High-Speed USB 2.
SARA-R4 series - System integration manual SARA-R422, SARA-R422S, SARA-R422M8S modules include a secondary auxiliary UART interface (UART AUX) for communication with an application host processor, supporting AT commands, data communication, GNSS tunneling 29, FW update by means of FOAT, with settings configurable by dedicated AT commands (for more details, see the SARA-R4 series AT commands manual [2]): • • • 4-wire serial port with RS-232 functionality conforming to ITU-T V.
SARA-R4 series - System integration manual 1.9.1.3 UART multiplexer protocol SARA-R4 series modules include multiplexer functionality as per 3GPP TS 27.010 [9], on the primary main UART physical link. This is a data link protocol which uses HDLC-like framing and operates between the module (DCE) and the application processor (DTE) and allows a number of simultaneous sessions over the primary main UART physical link.
SARA-R4 series - System integration manual The SARA-R4 series module itself acts as a USB device and can be connected to a USB host such as a Personal Computer or an embedded application microprocessor equipped with compatible drivers. The USB_D+/USB_D- lines carry USB serial bus data and signaling according to the Universal Serial Bus revision 2.
SARA-R4 series - System integration manual the SARA-R4 series module acts as an I2C host which can communicate with I2C devices in accordance with the I2C bus specifications [10]. The SDA and SCL pins have internal pull-up to V_INT, so there is no need of additional pull-up resistors on the external application board. 1.10 Audio ☞ Audio is not supported by current product versions: I2S pins should not be driven from external.
SARA-R4 series - System integration manual 1.12 GNSS peripheral input output ☞ The GNSS peripheral input output pins are not supported by the SARA-R410M, SARA-R412M, SARA-R422 and SARA-R422S modules. SARA-R422M8S modules provides the following 1.8 V peripheral input output pins directly connected to the internal u-blox M8 GNSS chipset, as illustrated in Figure 3: • • • • The TXD_GNSS pin consisting in the UART data output of the internal u-blox M8 GNSS chipset.
SARA-R4 series - System integration manual 2 Design-in 2.1 Overview For an optimal integration of the SARA-R4 series modules in the final application board, follow the design guidelines stated in this section. Every application circuit must be suitably designed to guarantee the correct functionality of the relative interface, but a number of points require particular attention during the design of the application device.
SARA-R4 series - System integration manual 2.2 Supply interfaces 2.2.1 Module supply (VCC) 2.2.1.1 General guidelines for VCC supply circuit selection and design All the available VCC pins have to be connected to the external supply minimizing the power loss due to series resistance. GND pins are internally connected.
SARA-R4 series - System integration manual voltage on VCC pins, and it should be selected according to the application requirements. A DC/DC switching charger is the typical choice when the charging source has a high nominal voltage (e.g. ~12 V), whereas a linear charger is the typical choice when the charging source has a relatively low nominal voltage (~5 V). If both a permanent primary supply / charging source (e.g. ~12 V) and a rechargeable back-up battery (e.g. 3.
SARA-R4 series - System integration manual Figure 20 and the components listed in Table 10 show an example of a high reliability power supply circuit for the SARA-R4 series modules that support 2G radio access technology.
SARA-R4 series - System integration manual Figure 21 and the components listed in Table 11 show an example of a high reliability power supply circuit for SARA-R410M modules, which do not support the 2G radio access technology. In this example, the module VCC is supplied by a step-down switching regulator capable of delivering the maximum peak / pulse current specified for the LTE use-case, with low output ripple and with fixed switching frequency in PWM mode operation greater than 1 MHz.
SARA-R4 series - System integration manual Figure 22 and the components listed in Table 12 show an example of a low cost power supply circuit suitable for all the SARA-R4 series modules, where the module VCC is supplied by a step-down switching regulator capable of delivering the highest peak / pulse current specified for the 2G use-case, transforming a 12 V supply input.
SARA-R4 series - System integration manual 2.2.1.3 Guidelines for VCC supply circuit design using LDO linear regulator The use of a linear regulator is suggested when the difference from the available supply rail source and the VCC value is low. The linear regulators provide high efficiency when transforming a 5 VDC supply to a voltage value within the module VCC normal operating range.
SARA-R4 series - System integration manual Figure 24 and the components listed in Table 14 show an example of a high reliability power supply circuit for SARA-R410M modules, which do not support the 2G radio access technology, where the module VCC is supplied by an LDO linear regulator capable of delivering maximum peak / pulse current specified for LTE use-case, with suitable power handling capability.
SARA-R4 series - System integration manual Figure 25 and the components listed in Table 15 show an example of a low cost power supply circuit, where the VCC module supply is provided by an LDO linear regulator capable of delivering the specified highest peak / pulse current, with an appropriate power handling capability. The regulator described in this example supports a limited input voltage range and it includes internal circuitry for current and thermal protection.
SARA-R4 series - System integration manual 2.2.1.
SARA-R4 series - System integration manual The Battery Charger IC, as linear charger, is more suitable for applications where the charging source has a relatively low nominal voltage (~5 V), so that a switching charger is suggested for applications where the charging source has a relatively high nominal voltage (e.g. ~12 V, see section 2.2.1.7 for the specific design-in).
SARA-R4 series - System integration manual A power management IC should meet the following prerequisites to comply with the module VCC requirements summarized in Table 6: • • • High efficiency internal step down converter, with characteristics as indicated in section 2.2.1.
SARA-R4 series - System integration manual Using a battery pack with an internal NTC resistor, the MP2617H can monitor the battery temperature to protect the battery from operating under unsafe thermal conditions.
SARA-R4 series - System integration manual 2.2.1.
SARA-R4 series - System integration manual 2.2.1.9 Guidelines for removing VCC supply Removing the VCC power can be useful to minimize the current consumption when the SARA-R4 series modules are switched off or when the modules are in deep sleep Power Saving Mode.
SARA-R4 series - System integration manual 2.2.1.10 Additional guidelines for VCC supply circuit design To reduce voltage drops, use a low impedance power source. The series resistance of the supply lines (connected to the modules’ VCC and GND pins) on the application board and battery pack should also be considered and minimized: cabling and routing must be as short as possible to minimize losses. Three pins are allocated to VCC supply connection. Several pins are designated for GND connection.
SARA-R4 series - System integration manual ☞ ESD sensitivity rating of the VCC supply pins is 1 kV (HBM according to JESD22-A114). Higher protection level can be required if the line is externally accessible on the application board, e.g. if accessible battery connector is directly connected to the supply pins. Higher protection level can be achieved by mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor) close to accessible point. 2.2.1.
SARA-R4 series - System integration manual 2.2.1.12 Guidelines for grounding layout design Good connection of the module GND pins with application board solid ground layer is required for correct RF performance. It significantly reduces EMC issues and provides a thermal heat sink for the module. • • • • • • • Connect each GND pin with application board solid GND layer.
SARA-R4 series - System integration manual 2.3 System functions interfaces 2.3.1 2.3.1.1 Module PWR_ON / PWR_CTRL input Guidelines for PWR_ON / PWR_CTRL circuit design SARA-R4 series PWR_ON / PWR_CTRL input is equipped with an internal active pull-up resistor; an external pull-up resistor is not required and should not be provided. If connecting the PWR_ON / PWR_CTRL input to a push button, the pin will be externally accessible on the application device.
SARA-R4 series - System integration manual 2.3.2 2.3.2.1 Module RESET_N input Guidelines for RESET_N circuit design The RESET_N input line of the SARA-R410M and SARA-R412M modules is equipped with an internal pull-up; an external pull-up resistor is not required. If connecting the RESET_N input to a push button, the pin will be externally accessible on the application device. According to EMC/ESD requirements of the application, an additional ESD protection device (e.g.
SARA-R4 series - System integration manual 2.4 Antenna interfaces SARA-R4 series modules provide an RF interface for connecting the external antenna: the ANT pin represents the RF input/output for RF signals transmission and reception. SARA-R422M8S modules provide also a GNSS RF interface for connecting the external GNSS antenna: the ANT_GNSS pin represents the GNSS RF input for GNSS signals reception.
SARA-R4 series - System integration manual 2.4.1.2 ☞ Guidelines for RF transmission lines design The GNSS antenna RF interface is supported by SARA-R422M8S modules only. Any RF transmission line, such as the ones from the ANT and ANT_GNSS pads up to the related antenna connector or up to the related internal antenna pad, must be designed so that the characteristic impedance is as close as possible to 50 .
SARA-R4 series - System integration manual If the distance between the transmission line and the adjacent GND area (on the same layer) does not exceed 5 times the width of the line, use the “Coplanar Waveguide” model for the 50 calculation.
SARA-R4 series - System integration manual 2.4.1.3 ☞ Guidelines for RF termination design The GNSS antenna RF interface is supported by SARA-R422M8S modules only. The RF termination must provide a characteristic impedance of 50 as well as the RF transmission line up to the RF termination, to match the characteristic impedance of ANT and ANT_GNSS ports. However, real antennas do not have a perfect 50 load on all the supported frequency bands.
SARA-R4 series - System integration manual • • Place the antenna far from sensitive analog systems or employ countermeasures to reduce EMC or EMI issues. Be aware of interaction between co-located RF systems since the LTE transmitted power may interact or affect the performance of companion systems as a GNSS receiver (see section 2.4.4 for further details and design-in guidelines regarding Cellular / GNSS RF coexistence). 2.4.2 2.4.2.
SARA-R4 series - System integration manual In both of cases, selecting external or internal antennas, these recommendations should be observed: • • • Select an antenna providing optimal return loss / VSWR / efficiency figure over all the operating cellular frequencies. Select an antenna providing the worst possible return loss / VSWR / efficiency figure in the GNSS frequency band, to optimize the RF coexistence between the cellular and the GNSS systems (see section 2.4.
SARA-R4 series - System integration manual Table 24 lists some examples of possible internal off-board PCB-type antennas with cable and connector. Manufacturer Part number Product name Description PulseLarsen Antennas W3929B0100 Taoglas FXUB64.18.0150A Taoglas FXUB63.07.0150C Laird Tech. EFF692SA3S Revie Flex Flexible LTE antenna 689..875 MHz, 1710..2500 MHz 90.0 x 20.0 mm Antenova SRFL026 Mitis GSM / WCDMA / LTE antenna on flexible PCB with cable and U.FL 689..960 MHz, 1710..
SARA-R4 series - System integration manual 2.4.3 GNSS antenna RF interface (ANT_GNSS) ☞ ☞ The GNSS antenna RF interface is supported by SARA-R422M8S modules only. For additional information and guidelines regarding the GNSS design, see the u-blox SARA-R4 / SARA-R5 positioning implementation application note [20]. The antenna and its placement are critical system factors for accurate GNSS reception. Use of a ground plane will minimize the effects of ground reflections and enhance the antenna efficiency.
SARA-R4 series - System integration manual SAW LNA SARA-R422M8S 31 ANT_GNSS 44 ANT_ON GND Figure 41: Typical circuit for best performance and improved jamming immunity with GNSS passive antenna The external LNA can be selected to deliver the performance needed by the application in terms of: • Noise figure (sensitivity) • Selectivity and linearity (robustness against jamming) • Robustness against RF power Depending on the characteristics of the supply source (DC/DC regulator, linear LDO regulator or o
SARA-R4 series - System integration manual Table 27 lists examples of LNA suitable for the GNSS RF input of SARA-R422M8S modules.
SARA-R4 series - System integration manual To avoid damaging the bias-T series inductor in the case of a short circuit at the antenna connector, it is recommended to implement a proper over-current protection circuit, which may consist in a series resistor as in the example illustrated in Figure 42.
SARA-R4 series - System integration manual Table 32 lists examples of active antennas to be used with SARA-R422M8S modules. Manufacturer Part number Product name Tallysman TW3400 Active antenna– 2.5 - 16 V GPS / SBAS / QZSS / GLONASS Tallysman TW3710 Active antenna, 2.5 – 16 V GPS / SBAS / QZSS / GLONASS / Galileo / BeiDou Taoglas AA.162.301111 Taoglas MA310.A.LB.001 Magnet mount antenna, 1.8 – 5.5 V GPS / SBAS / QZSS / GLONASS Inpaq B3G02G-S3-01-A SMA plug active antenna, 3.
SARA-R4 series - System integration manual In-band interference In-band interference signals are typically caused by harmonics from displays, switching converters, micro-controllers and bus systems. Moreover, considering for example the LTE band 13 high channel transmission frequency (787 MHz) and the GPS operating band (1575.42 MHz ± 1.023 MHz), the second harmonic of the cellular signal is exactly within the GPS operating band.
SARA-R4 series - System integration manual • • ensuring at least 15 – 20 dB isolation between antennas in the GNSS band by implementing the most suitable placement for the antennas, considering in particular the related radiation diagrams of the antennas: better isolation results from antenna patterns with radiation lobes in different directions considering the GNSS frequency band.
SARA-R4 series - System integration manual 2.4.5 2.4.5.1 Antenna detection interface (ANT_DET) Guidelines for ANT_DET circuit design Figure 46 and Table 34 describe the recommended schematic / components for the antenna detection circuit that must be provided on the application board and for the diagnostic circuit that must be provided on the antenna’s assembly to achieve antenna detection functionality.
SARA-R4 series - System integration manual The DC impedance at RF port for some antennas may be a DC open (e.g. linear monopole) or a DC short to reference GND (e.g. PIFA antenna).
SARA-R4 series - System integration manual 2.4.5.2 Guidelines for ANT_DET layout design Figure 47 describes the recommended layout for the antenna detection circuit to be provided on the application board to achieve antenna detection functionality, implementing the recommended schematic described in the previous Figure 46 and Table 34: • • • • • • The ANT pin must be connected to the antenna connector by means of a 50 transmission line, implementing the design guidelines described in section 2.4.
SARA-R4 series - System integration manual 2.5 SIM interface 2.5.1 2.5.1.
SARA-R4 series - System integration manual 2.5.1.2 Guidelines for single SIM card connection without detection A removable SIM card placed in a SIM card holder must be connected to the SIM card interface of SARA-R4 series modules as described in Figure 48, where the optional SIM detection feature is not implemented. Follow these guidelines to connect the module to a SIM connector without SIM presence detection: • • • • • • Connect the UICC / SIM contacts C1 (VCC) to the VSIM pin of the module.
SARA-R4 series - System integration manual 2.5.1.3 Guidelines for single SIM chip connection A Surface-Mounted SIM chip (M2M UICC Form Factor) must be connected the SIM card interface of the SARA-R4 series modules as described in Figure 49. Follow these guidelines to connect the module to a Surface-Mounted SIM chip without SIM presence detection: • • • • • • Connect the UICC / SIM contacts C1 (VCC) to the VSIM pin of the module. Connect the UICC / SIM contact C7 (I/O) to the SIM_IO pin of the module.
SARA-R4 series - System integration manual • Connect one pin of the normally-open mechanical switch integrated in the SIM connector (as the SW2 pin in Figure 50) to the GPIO5 input pin, providing a weak pull-down resistor (e.g. 470 k, as R2 in Figure 50). Connect the other pin of the normally-open mechanical switch integrated in the SIM connector (SW1 pin in Figure 50) to V_INT 1.8 V supply output by means of a strong pull-up resistor (e.g. 1 k, as R1 in Figure 50) Provide a 100 nF bypass capacitor (e.g.
SARA-R4 series - System integration manual 2.5.2 Guidelines for SIM layout design The layout of the SIM card interface lines (VSIM, SIM_CLK, SIM_IO, SIM_RST may be critical if the SIM card is placed far away from the SARA-R4 series modules or in close proximity to the RF antenna: these two cases should be avoided or at least mitigated as described below. In the first case, the long connection can cause the radiation of some harmonics of the digital data frequency as any other digital interface.
SARA-R4 series - System integration manual 2.6 Data communication interfaces 2.6.1 2.6.1.1 UART interface Guidelines for UART circuit design Providing the full RS-232 functionality (using the complete V.24 link)36 If RS-232 compatible signal levels are needed, two different external voltage translators can be used to provide full RS-232 (9 lines) functionality: e.g. using the Texas Instruments SN74AVC8T245PW for the translation from 1.8 V to 3.3 V, and the Maxim MAX3237E for the translation from 3.
SARA-R4 series - System integration manual Providing the TXD, RXD, RTS, CTS and DTR lines only 38 If the functionality of the DSR, DCD and RI lines is not required, or the lines are not available: • Leave DSR, DCD and RI lines of the module floating If RS-232 compatible signal levels are needed, two different external voltage translators (e.g. Maxim MAX3237E and Texas Instruments SN74AVC4T774) can be used. The Texas Instruments chips provide the translation from 1.8 V to 3.
SARA-R4 series - System integration manual Table 39: UART application circuit components with partial V.24 link (6-wire) in DTE/DCE serial communication (3.
SARA-R4 series - System integration manual Providing the TXD and RXD lines only 42 ☞ Providing the TXD and RXD lines only is not recommended if the multiplexer functionality is used in the application: providing also at least the HW flow control (RTS and CTS lines) is recommended, and it is in paricular necessary if the low power mode is enabled by +UPSV AT command.
SARA-R4 series - System integration manual Additional considerations If a 3.0 V Application Processor (DTE) is used, the voltage scaling from any 3.0 V output of the DTE to the corresponding 1.8 V input of the module (DCE) can be implemented as an alternative low-cost solution, by means of an appropriate voltage divider. Consider the value of the pull-down / pull-up integrated at the input of the module (DCE) for the correct selection of the voltage divider resistance values.
SARA-R4 series - System integration manual 2.6.2 USB interface 2.6.2.1 Guidelines for USB circuit design The USB_D+ and USB_D- lines carry the USB serial data and signaling. The lines are used in singleended mode for full speed signaling handshake, as well as in differential mode for high speed signaling and data transfer. USB pull-up or pull-down resistors and external series resistors on USB_D+ and USB_D- lines as required by the USB 2.
SARA-R4 series - System integration manual The SARA-R422-00B, SARA-R422S-00B and SARA-R422M8S-00B modules product versions do not support AT command / data communication over USB interface: the USB interface is available on these modules product versions for FW upgrade by means of the dedicated u-blox EasyFlash tool and for diagnostic purposes only. Therefore, the USB interface of these modules product versions is not designed to be connected to an external host processor mounted on the application board.
SARA-R4 series - System integration manual Table 43: Components for USB application circuits for SARA-R422, SARA-R422S and SARA-R422M8S modules 2.6.2.2 Guidelines for USB layout design The USB_D+ / USB_D- lines require accurate layout design to achieve reliable signaling at the high speed data rate (up to 480 Mb/s) supported by the USB serial interface. The characteristic impedance of USB_D+ / USB_D- lines is specified by the USB 2.0 specification [5].
SARA-R4 series - System integration manual 2.6.3 2.6.3.1 ☞ 2.6.4.1 SDIO interface Guidelines for SDIO circuit design The SDIO interface is not available on SARA-R422, SARA-R422S and SARA-R422M8S modules, and it is not supported by current product versions of SARA-R410M and SARA-R412M modules: the SDIO interface pins should not be driven by any external device. 2.6.5 2.6.5.
SARA-R4 series - System integration manual Connection with u-blox 1.8 V GNSS receivers ☞ Dedicated AT commands for external u-blox GNSS receiver communication and control are not supported by SARA-R422 and SARA-R422M8S product versions. Figure 63 shows an application circuit for connecting the cellular module to an external u-blox 1.8 V GNSS receiver: • • • The SDA and SCL pins of the cellular module are directly connected to the related pins of the ublox 1.8 V GNSS receiver.
SARA-R4 series - System integration manual Connection with u-blox 3.0 V GNSS receivers ☞ Dedicated AT commands for external u-blox GNSS receiver communication and control are not supported by SARA-R422 and SARA-R422M8S product versions. Figure 64 shows an application circuit for connecting the cellular module to an external u-blox 3.0 V GNSS receiver: • • • As the SDA and SCL pins of the cellular module are not tolerant up to 3.0 V, the connection to the related I2C pins of the u-blox 3.
SARA-R4 series - System integration manual 2.6.5.2 Guidelines for DDC (I2C) layout design The DDC (I2C) serial interface requires the same consideration regarding electro-magnetic interference as any other digital interface. Keep the traces short and avoid coupling with RF line or sensitive analog inputs, since the signals can cause the radiation of some harmonics of the digital data frequency. 2.7 Audio 2.7.
SARA-R4 series - System integration manual ☞ ESD sensitivity rating of the GPIO pins is 1 kV (HBM according to JESD22-A114). Higher protection level could be required if the lines are externally accessible and it can be achieved by mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor) close to accessible points. ☞ If the GPIO pins are not used, they can be left unconnected on the application board. 2.8.
SARA-R4 series - System integration manual 2.10 Reserved pins (RSVD) SARA-R4 series modules have pins reserved for future use, marked as RSVD. All the RSVD pins are to be left unconnected on the application board, except for the RSVD pin number 33 that can be externally connected to ground by 0 series jumper. ☞ It is highly recommended to provide accessible test point directly connected to the RSVD #33 pin for diagnostic purpose (see Figure 60). 2.
SARA-R4 series - System integration manual 2.12 Module footprint and paste mask Figure 67 and Table 47 describe the suggested footprint (i.e. copper mask) and paste mask layout for SARA modules: the proposed land pattern layout reflects the modules’ pins layout, while the proposed stencil apertures layout is slightly different (see the F’’, H’’, I’’, J’’, O’’ parameters compared to the F’, H’, I’, J’, O’ ones).
SARA-R4 series - System integration manual 2.13 Thermal guidelines ☞ The module operating temperature range is specified in the SARA-R4 series data sheet [1]. The most critical condition concerning module thermal performance is the uplink transmission at maximum power (data upload in connected mode), when the baseband processor runs at full speed, radio circuits are all active and the RF power amplifier is driven to higher output RF power.
SARA-R4 series - System integration manual 2.14 Schematic for SARA-R4 series module integration 2.14.1 Schematic for SARA-R4 series modules Figure 68 is an example of a schematic diagram where a SARA-R4 series module is integrated into an application board using almost all available interfaces and functions. SARA-R4 series 3V8 Ferrite Bead 68pF 100uF 100nF 10nF VCC 52 VCC 53 VCC 15pF ANT 56 39nH GND ANT_DET 27pF TP TP Open drain output TP USB 2.
SARA-R4 series - System integration manual 2.15 Design-in checklist This section provides a design-in checklist. 2.15.1 Schematic checklist The following are the most important points for a simple schematic check: DC supply must provide a nominal voltage at VCC pin within the operating range limits. VCC voltage supply should be clean, with very low ripple/noise: provide the suggested bypass capacitors, in particular if the application device integrates an internal antenna.
SARA-R4 series - System integration manual The VCC bypass capacitors in the picoFarad range should be placed as close as possible to the VCC pins, in particular if the application device integrates an internal antenna. Ensure an optimal grounding connecting each GND pin with application board solid ground layer.
SARA-R4 series - System integration manual 3 ☞ Handling and soldering No natural rubbers, no hygroscopic materials or materials containing asbestos are employed. 3.1 Packaging, shipping, storage and moisture preconditioning For information pertaining to SARA-R4 series reels / tapes, Moisture Sensitivity levels (MSD), shipment and storage information, as well as drying for preconditioning, see the SARA-R4 series data sheet [1] and the u-blox package information user guide [18]. 3.
SARA-R4 series - System integration manual 3.3 Soldering 3.3.1 Soldering paste "No Clean" soldering paste is strongly recommended for SARA-R4 series modules, as it does not require cleaning after the soldering process has taken place. The paste listed in the example below meets these criteria. Soldering Paste: OM338 SAC405 / Nr.143714 (Cookson Electronics) Alloy specification: 95.5% Sn / 3.9% Ag / 0.6% Cu (95.5% Tin / 3.9% Silver / 0.6% Copper) 95.5% Sn / 4.0% Ag / 0.5% Cu (95.5% Tin / 4.
SARA-R4 series - System integration manual Cooling phase A controlled cooling avoids negative metallurgical effects (solder becomes more brittle) of the solder and possible mechanical tensions in the products. Controlled cooling helps to achieve bright solder fillets with a good shape and low contact angle. • Temperature fall rate: max 4 °C/s ☞ To avoid falling off, modules should be placed on the topside of the motherboard during soldering.
SARA-R4 series - System integration manual 3.3.5 Repeated reflow soldering Repeated reflow soldering processes and soldering the module upside-down are not recommended. Boards with components on both sides may require two reflow cycles. In this case, the module should always be placed on the side of the board that is submitted into the last reflow cycle. The reason for this (besides others) is the risk of the module falling off due to the significantly higher weight in relation to other components.
SARA-R4 series - System integration manual 3.3.11 Grounding metal covers Attempts to improve grounding by soldering ground cables, wick or other forms of metal strips directly onto the EMI covers is done at the customer's own risk. The numerous ground pins should be sufficient to provide optimum immunity to interference and noise. ☞ u-blox gives no warranty for damages to the cellular modules caused by soldering metal cables or any other forms of metal strips directly onto the EMI covers. 3.3.
SARA-R4 series - System integration manual 4 Approvals 4.
SARA-R4 series - System integration manual Table 48 summarizes the main approvals achieved or planned for SARA-R410M and SARA-R412M modules (LTE-M = LTE Cat M1).
SARA-R4 series - System integration manual Table 49 summarizes the main approvals planned for SARA-R422, SARA-R422S and SARA-R422M8S modules.
SARA-R4 series - System integration manual Table 50 summarizes how some of the SARA-R410M and SARA-R412M modules are identified by various bodies.
SARA-R4 series - System integration manual The SARA-R4 series modules include the capability to configure the device by selecting the operating mobile network operator profile, radio access technology, and bands. In the SARA-R4 series AT commands manual [2], see the +UMNOPROF, +URAT, and +UBANDMASK AT commands.
SARA-R4 series - System integration manual 4.2.2 Declaration of Conformity This device complies with Part 15 of FCC rules.
SARA-R4 series - System integration manual 4.2.3 Modifications The FCC requires the user to be notified that any changes or modifications made to this device that are not expressly approved by u-blox could void the user's authority to operate the equipment. ⚠ Manufacturers of mobile or fixed devices incorporating the SARA-R4 series modules are authorized to use the FCC Grants of the SARA-R4 series modules for their own final products according to the conditions referenced in the certificates.
SARA-R4 series - System integration manual 4.3 Innovation, Science, Economic Development Canada notice ISED Canada (formerly known as IC - Industry Canada) Certification Numbers: • • • u-blox SARA-R410M cellular modules: u-blox SARA-R412M cellular modules: u-blox SARA-R422, SARA-R422S, SARA-R422M8S cellular modules: 4.3.1 8595A-2AGQN4NNN 8595A-UBX18ZO01 8595A-UBX20VA01 Declaration of Conformity This device complies with the ISED Canada license-exempt RSS standard(s).
SARA-R4 series - System integration manual 4.3.2 Modifications ISED Canada requires the user to be notified that any changes or modifications made to this device that are not expressly approved by u-blox could void the user's authority to operate the equipment.
SARA-R4 series - System integration manual ⚠ Avis d'Innovation, Sciences et Développement économique Canada (ISDE) Cet appareil numérique de classe B est conforme aux normes canadiennes CAN ICES-3(B) / NMB-3(B).
SARA-R4 series - System integration manual ⚠ Radiofrequency radiation exposure Information: this equipment complies with radiation exposure limits prescribed for an uncontrolled environment for fixed and mobile use conditions. This equipment should be installed and operated with a minimum distance of 20 cm between the radiator and the body of the user or nearby persons.
SARA-R4 series - System integration manual 4.6 ANATEL Brazil • SARA-R410M-02B modules ANATEL Homologation No. 07889-19-05903 07889-19-05903 • SARA-R412M-02B modules ANATEL Homologation No. 07927-19-05903 07927-19-05903 4.7 Australian Conformance The u-blox SARA-R410M-02B, SARA-R410M-83B and SARA-R412M-02B modules are compliant with the applicable standards made by the Australian Communications and Media Authority (ACMA).
SARA-R4 series - System integration manual 5 Product testing 5.1 u-blox in-series production test u-blox focuses on high quality for its products. All units produced are fully tested automatically on the production line. Stringent quality control processes have been implemented in the production line. Defective units are analyzed in detail to improve production quality. This is achieved with automatic test equipment (ATE) in the production line, which logs all production and measurement data.
SARA-R4 series - System integration manual 5.2 Test parameters for OEM manufacturers Because of the testing done by u-blox (with 100% coverage), an OEM manufacturer does not need to repeat the firmware tests or measurements of the module RF performance or tests over analog and digital interfaces in their production test.
SARA-R4 series - System integration manual The minimum recommended RF verification in production consists in forcing the module to transmit in a supported frequency the +UTEST AT command, and then checking that some power is emitted from the antenna system using any suitable power detector, power meter or equivalent equipment. ☞ See the SARA-R4 series AT commands manual [2] for the +UTEST AT command syntax description and detail guide of usage.
SARA-R4 series - System integration manual Appendix A ☞ Migration between SARA modules Detailed and updated guidelines to migrate between the u-blox SARA-G3, SARA-G4, SARA-U2, SARA-N2, SARA-N3, SARA-R4 and SARA-R5 series modules are available in the u-blox SARA modules migration guidelines application note [19].
SARA-R4 series - System integration manual Abbreviation Definition GITEKI Gijutsu kijun tekigō shōmei - technical standard conformity certification (Japan) GLONASS GLObal NAvigation Satellite System (Russian satellite navigation system) GMSK Gaussian Minimum-Shift Keying modulation GND Ground GNSS Global Navigation Satellite System GPIO General Purpose Input Output GPRS General Packet Radio Service GPS Global Positioning System HBM Human Body Model HTTP HyperText Transfer Protocol HW
SARA-R4 series - System integration manual Abbreviation Definition SMA Sub-Miniature version A SMD Surface Mounting Device SMS Short Message Service SPI Serial Peripheral Interface SRF Self-Resonant Frequency SSL Secure Socket Layer TBD To Be Defined TCP Transmission Control Protocol TDD Time Division Duplex TDMA Time Division Multiple Access TIS Total Isotropic Sensitivity TP Test-Point TRP Total Radiated Power UART Universal Asynchronous Receiver-Transmitter UDP User Datagr
SARA-R4 series - System integration manual Related documentation [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] ☞ u-blox SARA-R4 series data sheet, UBX-16024152 u-blox SARA-R4 series AT commands Manual, UBX-17003787 u-blox SARA-R42 series application development guide application note, UBX-20050829 u-blox EVK-R4 user guide, UBX-16029216 Universal Serial Bus revision 2.0 specification, https://www.usb.org/ ITU-T Recommendation V.
SARA-R4 series - System integration manual Revision history Revision Date Name Comments R01 31-Jan-2017 sfal Initial release R02 05-May-2017 sfal / sses Updated supported features and characteristics Extended document applicability to SARA-R410M-01B product version R03 24-May-2017 sses Updated supported features and electrical characteristics R04 19-Jul-2017 sses Updated supported features and electrical characteristics Added FCC and ISED info for SARA-R410M-01B modules Extended document
SARA-R4 series - System integration manual Revision Date Name Comments R18 09-Dec-2020 sses Extended document applicability to SARA-R410M-63B-01 R19 23-Feb-2021 sses Extended document applicability to product versions SARA-R410M-02B-03, SARA-R412M-02B-03 R20 11-Mar-2021 sses Extended document applicability to product versions SARA-R422-00B, SARA-R422M8S-00B, SARA-R422S-00B Minor other corrections and clarifications.
SARA-R4 series - System integration manual Contact For complete contact information, visit us at www.u-blox.com. u-blox Offices North, Central and South America u-blox America, Inc. Phone: E-mail: +1 703 483 3180 info_us@u-blox.com Regional Office West Coast: Phone: E-mail: +1 408 573 3640 info_us@u-blox.com Headquarters Europe, Middle East, Africa Asia, Australia, Pacific u-blox AG Phone: +65 6734 3811 E-mail: info_ap@u-blox.com Support: support_ap@u-blox.
