Implemented in 40nm CMOS, the radio achieves a reduced supply voltage (20 percent), power consumption (25 percent), and chip area (35 percent), as compared to the previous 90nm RF front-end design.
“From healthcare to smart buildings, ubiquitous wireless sensors connected through cellular devices are becoming widely used in everyday life,” said Harmke De Groot, Department Director at imec. “The radio consumes the majority of the power of the total system and is one of the most critical components to enable these emerging applications. Moreover, a low-cost area-efficient radio design is an important catalyst for developing small sensor applications, seamlessly integrated into the environment. Implementing an ultralow power radio will increase the autonomy of the sensor device, increase its quality, functionality and performance and enable the reduction of the battery size, resulting in a smaller device, which in case of wearable systems, adds to user’s comfort.”
Imec, Holst Centre and Renesas’ new 2.4GHz radio achieves world-class energy efficiency by employing a digital-intensive RF architecture tightly integrated with the digital baseband (DBB) and a microcontroller (MCU). Additionally, several low-voltage techniques are adopted to ensure sub-1V operation, achieving best-in-class 3.7mW RX and 4.4mW TX power consumption. Furthermore, the digital-intensive RF design reduces the analog core area to 1.3mm2, and the DBB/MCU/SRAM occupies an area of 1.1mm2.
Fabricated in a 40nm CMOS process, the radio supports the most common standards for mobile sensor networks (BLE, IEEE802.15.4). A mixed-mode fast Carrier Frequency Offset (CFO) compensation through a 2-point injection All-Digital Phase-Locked Loop (AD-PLL) expands the receiver’s tolerance to Carrier Frequency Offset (CFO) from ±20ppm to ±60ppm. An All-Digital PLL is used because of its small area and extensive self-calibration. An excellent receiver (RX) sensitivity of -93.5dBm (BLE spec.: <-70dBm) for BLE was measured, with a packet error rate (PER) of 30.8 percent. The RX with fast Automatic Gain Control (AGC) has a dynamic range from the sensitivity level up to -5dBm (BLE spec.: >-10dBm), and fulfills BLE requirement on adjacent channel rejection with sufficient margin.
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Imec (imec.be) performs world-leading research in nanoelectronics and photovoltaics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in the Netherlands, Taiwan, US, China, India and Japan. Its staff of over 2,080 people includes more than 670 industrial residents and guest researchers. In 2013, imec's revenue (P&L) totaled 332 million euro.
Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a "stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.)and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited).
About Holst Centre
Holst Centre (holstcentre.com) is an independent open-innovation R&D centre that develops generic technologies for Wireless Autonomous Transducer Solutions and for Systems-in-Foil. A key feature of Holst Centre is its partnership model with industry and academia around shared roadmaps and programs. It is this kind of cross-fertilization that enables Holst Centre to tune its scientific strategy to industrial needs.
Holst Centre was set up in 2005 by imec (Flanders, Belgium) and TNO (The Netherlands) with support from the Dutch Ministry of Economic Affairs and the Government of Flanders. It is named after Gilles Holst, a Dutch pioneer in Research and Development and first director of Philips Research.
Located on High Tech Campus Eindhoven, Holst Centre benefits from the state-of-the-art on-site facilities. Holst Centre has over 180 employees from around 28 nationalities and a commitment from more than 45 industrial partners.
About Renesas Electronics Corporation
Renesas Electronics Corporation (renesas.com), the world's number one supplier of microcontrollers, is a premier supplier of advanced semiconductor solutions including microcontrollers, SoC solutions and a broad range of analog and power devices. Business operations began as Renesas Electronics in April 2010 through the integration of NEC Electronics Corporation (TSE:6723) and Renesas Technology Corp., with operations spanning research, development, design and manufacturing for a wide range of applications. Headquartered in Japan, Renesas Electronics has subsidiaries in approximately 20 countries worldwide.