Sub GHz makes IoT applications cover a longer distance and a wider scope

On the one hand, wireless communication is moving toward high frequency bandwidths to obtain faster transmission speeds, and on the other hand, it is moving toward low frequency bandwidths in order to pursue longer distances and a wider scope. Generally, low frequency bandwidth refers to the frequency band below 1 GHz, which is called Sub GHz in English. This article will introduce you to the characteristics of Sub GHz applications and the four Sub GHz transceivers and SoC from ON Semiconductor.

Low frequency transmission is more suitable for IoT applications

In respect of high frequency transmission, although a faster transmission speed can be obtained, the signal is easily blocked by obstacles and the transmission distance is short. By contrast, low frequency transmission is characterized by long transmission distance, wide scope, and good signal penetrability. Although the transmission speed is slow, it is quite suitable for Internet of Things (IoT) applications with less data transmission, so it has attracted more and more attention.

The so-called Sub GHz literally refers to wireless communication with a frequency band below 1 GHz, but many frequency bands that have been used in TV, radio, and mobile networks still need to be deducted. The frequency bands that are really used for IoT applications are mostly 315 MHz, 433 MHz, 868MHz, 915MHz, etc. The 169MHz frequency band can also be used in some countries, or the 779MHz frequency band is available in China.

The advantage of low frequency is that a longer transmission distance can be realized under the same transmission power. If 315MHz is used, the gap is about 8 times compared to WiFi's 2.4GHz. If WiFi covers a distance of up to 100 meters, 315MHz may realize a distance of up to 800 meters (64 times greater in terms of coverage area). In addition, Sub GHz does not require a high transmission rate, or complex modulation such as 16QAM, 64QAM, etc. Simple modulation (such as ASK, FSK, etc) can be implemented and the transmission distance is longer, up to several kilometers at the maximum.

Although Sub GHz has advantages, the disadvantage is that the available frequency bands have not been unified in countries, such as 310MHz available in Japan and 470MHz available in China. Therefore, in designing chips, chip makers try to make a single chip supporting multiple frequency bands. Here are four Sub GHz transceivers and SoC from ON Semiconductor.

AX5043: Ultra-low-power and narrow-band Sub GHz (27 - 1050 MHz) RF transceiver


The AX5043 is a true single-chip, narrow-band, ultra-low-power ASK and FSK RF transceiver for the 27 MHz to 1050 MHz frequency bands. It provides a unique ultra-low-power consumption combination for transmission and receiving operations, has the highest sensitivity and high selectivity, and can realize a link budget of 143 dB at a data rate of 1 kbps. If built-in forward error correction (FEC) is used, it can be extended to 146 dB without additional external components. The AX5043 has a minimum operating rate of 1 kbps in a 6.25 kHz channel.

The integrated voltage regulation system allows direct battery use and quick start-up, saving time and energy. In the power supply voltage range of 1.8 -3.6 V, the transmission power and receiving characteristics will not change. AX5043 supports FSK, MSK, 4-FSK, GFSK, GMSK, AFSK, and ASK modulation. In the transmission mode, all modulations are shaped.  It can meet the most stringent regulatory requirements for FSK modulation by adopting Gaussian filters with BT=0.3 or BT=0.5. The power ramping can be configured without restrictions. The maximum output power level is 16 dBm.

AX5043 has a carrier frequency range of 27 - 1050 MHz, ultra-low power consumption, constant TX output power over the entire VDD range of 1.8 - 3.6 V, fully autonomous minimum power consumption wake-on-radio mode (500 nA), and RX/TX packet requiring no intervention from a microcontroller.

AX5043 can be used over a wide frequency range and can realize low power consumption without sacrificing link budget or selectivity. The transmission power and receiving characteristics remain unchanged within the power supply voltage range. It has the ability to autonomously handle wake-on-radio cycles and support various packet formats that can be processed without microcontroller intervention. AX5043 can be applied to the IoT, automatic meter reading (AMR), security applications, building automation, wireless networks, and battery-powered portable applications.

AX5243: Ultra-low-power and narrow-band Sub GHz (27 - 1050 MHz) RF transceiver

AX5243 is a true single-chip, ultra-low-power, and narrow-band CMOS transceiver that can be used in licensed and unlicensed frequency bands from 27 MHz and 1050 MHz. The on-chip transceiver consists of a fully integrated RF front-end with modulator and demodulator. The baseband data processing can be implemented in an advanced, flexible communication controller, which can implement user-friendly communication through an SPI interface. It performs FSK, 4-FSK, GFSK, GMSK, MSK, ASK, and PSK modulation and supports any data rate from 0.1 kbps to 125 kbps.

The AX5243 can use a 1.8 V to 3.6 V power supply to operate at the temperature range of -40°C to 85°C. Depending on the output power, it consumes 7 - 48 mA at a carrier frequency of 868 MHz and 4 - 51 mA at a transmission frequency of 169 MHz. In receiving operation, it consumes 9-11 mA at a carrier frequency of 868 MHz and 6.5-8.5 mA at 169 MHz. It also has a fully integrated oscillator with the lowest power consumption internally. The oscillation frequency is 640 Hz +/- 1.5% in the default mode and 10.2 kHz +/- 1.5% in the fast mode. These accuracies can be achieved after calibrating the low-power oscillator and RF reference clock using internal hardware.

The capabilities of the AX5243 make it an ideal interface for integration into various battery-powered solutions, such as ticketing or as a transceiver for telemetric applications, e.g. used in sensors. The AX5243 has a carrier frequency range of 27 - 1050 MHz, has a highly sensitive and highly selective receiver, supports a low-power oscillator and wake-on-radio (WOR) mode, and automatic frequency control (AFC).

The AX5243 operates over a wide frequency range, supports data rates from 0.1 kbps to 125 kbps and 45 dB adjacent channel rejection, allows extremely low average receiver power, and is able to track the transmitter frequency within the RX filter bandwidth. AX5243 can be applied to the IoT, automatic meter reading, security applications, building automation, and wireless networks.

AXM0F243: Ultra-low-power and narrow-band Sub GHz (27 - 1050 MHz) ARM® Cortex®-M0+ wireless microcontroller


AXM0F243 is a system-on-chip (SoC) for true single chip wireless applications. The SoC includes a field proven narrow-band AX5043 RF transceiver core and a high-performance ARM® Cortex®-M0+ microcontroller (MCU) core. The AX5043 core is very powerful and can be programmed by software to take advantage of the widest array of modulation schemes available and data rates from 100 bps to 125 kbps to implement almost any proprietary or standard Sub GHz protocol.

With software programmability of the radio core, it also allows sharing of common hardware design for products loaded with different software, to enable customers to more easily manage multiple SKUs, or this device can also be used to implement multi-protocol solutions to implement a powerful gateway.

The integrated frequency synthesizer can generate any carrier frequency between 27 MHz to 1050 MHz. For frequencies lower than 400 MHz, VCO-integrated external inductors can be used, but for frequencies higher than 400 MHz, then integrated inductors can be used.

The AX5043 receiver is very robust and can achieve sensitivity as low as -137 dBm while consuming less than 10 mA. For applications that require antenna diversity, an integrated diversity controller is included, which can automatically control external antenna switches via a GPIO pin. The receiver also has a wake-on-radio function that can further reduce power consumption by allowing the MCU to sleep as long and as frequently as possible between radio events. The AX5043 transmitter includes a differential power amplifier that can produce up to 16 dBm or a single-ended option that can produce up to 13 dBm.

The high-performance ARM® Cortex®-M0+ operates at a frequency of up to 48 MHz and features 64 kB flash memory and 8 kB RAM. The MCU contains two independent serial communication blocks (SCB), which can be configured to perform I2C, SPI, UART, etc. The MCU has five 16-bit timers that can be used as counters, PWM modulators or pulse generators, and has 19 programmable GPIO pins.

In addition to the extremely powerful MCU core, the AXM0F243 MCU also has a powerful and unique analog function. The integrated 12-bit SAR ADC is capable of 1 Msps conversion and has single-ended and fully differential modes. The MCU also contains two current DACs, two ultra-low-power comparators, and two ultra-low-power operational amplifiers.

AXM0F243 is available in a 5mm x 7mm QFN40 package with a power supply range of 1.8V - 3.6V. It has the largest frequency range available on a single device. It has a built-in industry-standard MCU that enables software portability and supports the widest range of shaped modulation arrays (FSK, MSK, 4-FSK, GFSK, GMSK, AFSK, ASK, FM). With an excellent receiver and efficient transmitter, it has a high link budget and can carry out long-distance communication. It is an ultra-low-power and high performance device in a small package, suitable for a variety of battery-powered applications, and higher-level system integration is possible. With flexible digital I/O, it can be connected to sensors and other devices.

AXM0F243 can be used in automatic meter reading, security applications, home and building automation, industrial IoT and sensor networks, lighting and remote control, wireless applications, smart retail, and asset management. Common terminal products include electricity meters, remote controllers, sensor nodes, water meters, sensor gateways, gas meters, data loggers, street light controllers, security systems, thermostats, weather stations, etc.

AX8052F143: Ultra-low-power and narrow-band Sub GHz (27 - 1050 MHz) 8052 wireless microcontroller

The AX8052F143 is a single chip solution compatible with many standard applications in the IoTs. At 868MHz and 1.2 kbps, the sensitivity is -126 dBm and the power consumption is only 9.5 mA, which makes the AX8052F143 an outstanding device in this field. Low phase noise and a high-efficiency 16 dBm transmitter are notable features, with data rates ranging from 0.1 to 125 kbps. The frequency range from 27 MHz to 1050 MHz makes this RF microcontroller an ideal device for many applications, including automatic meter reading and security applications. The receiving current with an average duty-cycle of 4.5 µA is just one of many excellent parameters.

The AX8052F143 microcontroller core executes the industry-standard 8052 instruction set and can freely program the system clock between DC and 20 MHz. Since the instructions are executed in one cycle, the core can provide 20 MIPS. A 64 KB flash memory is provided to allow the application to be programmed in C language. The fully associative cache and pre-fetch controller hide the latency of the flash memory.

The AX8052F143 has a dual-channel DMA engine that can transfer data to XRAM and transfer data from XRAM to any peripheral on the chip. It provides a dedicated AES engine and uses its own DMA engine for encryption. Additional peripherals include three general purpose timers with optional sigma-delta output modes. The timers can be used as baud rate generators for the two UARTs and provide a master/slave SPI interface. In addition, there is a 10-bit, 500 k Sample/s ADC with flexible input mode, and a comparator that allows interfacing with analog data streams.

The AX8052F143 can operate over the frequency range from 27 MHz to 1050 MHz. It has a built-in ultra-low-power AX8052 MCU and a high-performance narrow-band RF transceiver in a 5mm x 7mm QFN40 package. Available in a wide frequency range, it consumes only 950 nA current in sleep mode, and has a wake-up timer during operation, and 256-byte SRAM retention. Supporting various types of modulation (FSK, MSK, 4-FSK, GFSK, GMSK, AFSK, ASK, FM), it is an ultra-low-power and high performance device in a small package, suitable for a variety of applications, including security applications, building automation, wireless applications, and automatic meter reading (AMR).


Featured Product

ON Semiconductor AX5043-1-TW30 RF Transceivers


Related news articles

Latest News

Sorry, your filter selection returned no results.

We've updated our privacy policy. Please take a moment to review these changes. By clicking I Agree to Arrow Electronics Terms Of Use  and have read and understand the Privacy Policy and Cookie Policy.

Our website places cookies on your device to improve your experience and to improve our site. Read more about the cookies we use and how to disable them here. Cookies and tracking technologies may be used for marketing purposes.
By clicking “Accept”, you are consenting to placement of cookies on your device and to our use of tracking technologies. Click “Read More” below for more information and instructions on how to disable cookies and tracking technologies. While acceptance of cookies and tracking technologies is voluntary, disabling them may result in the website not working properly, and certain advertisements may be less relevant to you.
We respect your privacy. Read our privacy policy here