Operational description

FCC ID: S9NSPSGRFC

Operational Description

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FCCID_3259782

SPSGRFC-915 module: some technical note about the Radio device embedded in the module, displayed in the Module Block Diagram as “SPIRIT1”. Description The SPIRIT1 is a very low-power RF transceiver, intended for RF wireless applications in the sub-1 GHz band. It is designed to operate both in the license-free ISM and SRD frequency bands at 169, 315, 433, 868, and 915 MHz, but can also be programmed to operate at other additional frequencies in the 300-348 MHz, 387-470 MHz, and 779-956 MHz bands. The air data rate is programmable from 1 to 500 kbps, and the SPIRIT1 can be used in systems with channel spacing of 12.5/25 kHz, complying with the EN 300 220 standard. It uses a very small number of discrete external components and integrates a configurable baseband modem, which supports data management, modulation, and demodulation. The data management handles the data in the proprietary fully programmable packet format also allows the M-Bus standard compliance format (all performance classes). However, the SPIRIT1 can perform cyclic redundancy checks on the data as well as FEC encoding/decoding on the packets. The SPIRIT1 provides an optional automatic acknowledgement, retransmission, and timeout protocol engine in order to reduce overall system costs by handling all the high-speed link layer operations. Moreover, the SPIRIT1 supports an embedded CSMA/CA engine. An AES 128-bit encryption co-processor is available for secure data transfer. The SPIRIT1 fully supports antenna diversity with an integrated antenna switching control algorithm. The SPIRIT1 supports different modulation schemes: 2-FSK, GFSK, OOK, ASK, and MSK. Transmitted/received data bytes are buffered in two different three-level FIFOs (TX FIFO and RX FIFO), accessible via the SPI interface for host processing.

A simplified block diagram of the SPIRIT1 is shown in Figure 1. The receiver architecture is low-IF conversion. The received RF signal is amplified by a twostage low-noise amplifier (LNA) and down-converted in quadrature (I and Q) to the intermediate frequency (IF). LNA and IF amplifiers make up the RX front-end (RXFE) and have programmable gain. At IF, I/Q signals are digitized by ADCs. The demodulated data is then provided to an external MCU either through the 96-byte RX FIFO, readable via SPI, or directly using a programmable GPIO pin. A 128-bit AES co-processor is available to perform (offline) data encryption/decryption to secure data transfer. The transmitter part of the SPIRIT1 is based on direct synthesis of the RF frequency. The power amplifier (PA) input is the LO generated by the RF synthesizer, while the output level can be configured between -30 dBm and +11 dBm in 0.5 dB steps. The data to be transmitted can be provided by an external MCU either through the 96-byte TX FIFO writable via SPI, or directly using a programmable GPIO pin. The SPIRIT1 supports frequency hopping, TX/RX and antenna diversity switch control, extending the link range and improving performance. The SPIRIT1 has a very efficient power management (PM) system. An integrated switched mode power supply (SMPS) regulator allows operation from a battery voltage ranging from +1.8 V to +3.6 V, and with power conversion efficiency of at least 80%. A crystal must be connected between XIN and XOUT. It is digitally configurable to operate with different crystals. As an alternative, an external clock signal can be used to feed XIN for proper operation. The SPIRIT1 also has an integrated low-power RC oscillator, generating the 34.7 kHz signal used as a clock for the slowest timeouts (i.e. sleeping and backoff). A standard 4-pin SPI bus is used to communicate with the external MCU. Four configurable general purpose I/Os are available.

Typical application diagram This section describes different application diagram of SPIRIT1 that can be used according to customer needs. In particular Figure 2 shows the default configuration, Figure 3 shows the TX boost mode configuration and Figure 4 shows the SMPS off configuration. The default configuration is giving the best power consumption figures. The TX boost mode configuration is used to increase TX output power and the SMPS off configuration is used to enhance sensitivity at the expense of power consumption. When using SMPS off configuration, SMPS should disabled by setting to1 bit DISABLE_SMPS in PM_CONFIG register. It is important the SDN pin to be driven by an external microcontroller. It should be set low when the supply voltage of the device is steady to VDD. A short circuit connection of the SDN pin to ground should be avoided.

RF receiver Characteristics measured over recommended operating conditions unless otherwise specified. All typical values are referred to T A = 25 °C, VBAT = 3.0 V, no frequency offset in the RX signal. All performance is referred to a 50 Ohm antenna connector, via the reference design.


life.augmented Table 13. RF receiver characteristics — sensitivity Symbol Parameter Test condition sMrs on smes OFF| Unit 169 MHz 2—FSK 1.2kbps (4 kHz dev. CH Filter=10 kHz) 17 123 dBm 169 MHz 2—GFSK (BT=0.5) 2.4kbps (2.4 kHz dev. CH 14 —121 dBm Sensitivity, 1% BER Fiter=? kHiz) (according to W—MBUS N mode specification) 169 MHz 2—FSK 38.4kbps (20 kz _ L dev. CH Filter=100 kHz) 104 109 dBm RX sens 169 MHz 2—GFSK (BT=0.5) 50 kbps (25 kHz dev. CH —104 —108 dBm Filter=100 kHz) 315 MHz 2—FSK 1.2 kbps (4.8 kHz Sensitivity, 1% PER (packet gev. CH Filter=58 KH2) ~108 —110 dBm length = 20 bytes) FEC pisaBLeD 315 MHz MSK 500 kbps (CH css css dBm Filter=800 kz)


RF transmitter Characteristics measured over recommended operating conditions unless otherwise specified. All typical values are referred to T A = 25 °C, VBAT = 3.0 V. All performance is referred to a 50 Ohm antenna connector, via the reference design.

'I life.augmented Table 14. RF transmitter characteristics (continued) Symbol Parameter Test conditions Min. Typ. Max. Unit RF = 310—320 MHz, harmonics measured d with with max output tout — — ar aBi m power) RF =310—320 MHz, 1.705 MHz <i< 30 MHz ~ <60 cBm RF = 310—320 MHz, . 30 MHz <t< Sn 1 — 60 dBm RF = 310—320 MHz, 88 MHz <t< preune — <60 dBm RF =310—320 MHz, 216 MHz <r< _ <eo cam Unwanted emissions |SOO Mz according to FCC part e = 310—320 MHz, 960 MHz <f — <60 dBm Pspurrce 15tharmonic included, using reference design) |RF = 902—928 MHz, 1.705 MHz <f< 30 MHz (@ max output power) . <70 cBm memmeswenr O |on| en 216NHMZ(@masouputpawen _ «70 cam mremer RF = 902923 MHz, 960 MHz <f — _ w1 cem (@ max output power) 2°" and 7‘" harmonics — 25 dBe

'l life.augmented Table 14. RF transmitter characteristics (continued) Symbol Parameter Test conditions Min. Typ. Mex. Unit RF =312—315 MHz,frequency below 1 GHz (@ max output — 41 dBm power, according to ARIB STD— Tos) RF =312—315 MHz,frequency above 1 GHz (@ max output — 48 dBm power, according to ARIB STD— Tos) RF =426—470 MFHz (@ max output power, according to ARIB STD— — <40 dBm Ter) RF =915—917 MHz and RF =920—930 MHz, f< 710 MHz — <55 dBm (@ max output power, accordina to ARIB STD—T108) RF =915—917 MHz and RF 20—930 MFHz, 710 MHz STS — «55 dBm 915 MHz (@ max output power, according to ARIB STD—T108) RF =915—917 MHz and RF =924—930 MHz, 915 MHz <f< — 36 dBm 930 MHz (@ max output power, P Unwanted emissions according to ARIB STD—T108) SPURARE according to ARIB RF =920—024 MHz, 915 MHz <f< 920.3 MHz (@ max output power, — <30 dbm according to ARIB STD—T108) RF =920—024 MHz, 920.3 MHz <f< 924.3 MFHz (@ max output — «55 dBm power, according to ARIB STD— T108) K =920—024 MHz, 924.3 MHz <f< 930 MHz (@ max output — 36 dBm power, according to ARIB STD— T108) RF =915—917 MHz and RF =920—930 MHz, 930 MHz <f< — «55 dBm 1000 MHz (@ max output power, according to ARIB STD—T108) RF =915—917 MHz and RF =920—030 MHz, 1000 MHz <i< — <60 dBm 1215 MHz (@ max output power, according to ARIB STD—T108) RF =915—917 MHz and RF =920—030 MHz, 1215 MHz <f — —38 dBm (@ max output power, according to ARIB STD—T108)

(For more information, please refer to the STM SPIRIT1 Datasheet).

SPSGRFC module: some technical note about the Antenna device used during the “FCC” and “IC” certifications as “EXTERNAL RF antenna”. (Data reported from the TAOGLAS Antenna Datasheet)

TI.19 is a high performance 915MHz ISM band dipole omni-directional antenna. The hinged design enables the antenna to be positioned at its most suitable angle. This antenna features a SMA(M) Plug Connector. For a lot of antenna applications, such as Wi-Fi Hotspot or cellular Pico-cell, the antenna of the operator’s device and the antenna of the user’s remote device are not on the same horizontal level. The TI.19 has been designed with a butterfly shape radiation pattern, to help counteract this effect. Antenna General Data Specifications:

Antenna return loss Antenna VSWR

Radiation Efficiency Peak Gain

Average Gain Radiation Pattern (Typical)


Document Created: 2016-10-03 17:30:50
Document Modified: 2016-10-03 17:30:50
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