Ultra-low power transceiver suitable for Bluetooth 5

In the IoT, numerous tiny sensor nodes are embedded in our environment. Reducing the power consumption and enabling operation at low supply voltage of IoT radio transceivers is key to enable reliable multi-year battery life of the billions of IoT devices in our environment. Furthermore, new applications are empowered by reducing power consumption and supply voltage, such as leave-behind sensors or wearables.

imec, together with Renesas, developed a fully-integrated, highly energy efficient BT5 transceiver which supposedly showcases the best RX figure-of-merit (FoM) and the lowest supply voltage. A low supply voltage of 0.8V is beneficial because it extends battery life by up to 50%, reduces the complexity of the power management unit, and allows the use of a wider range of energy sources such as energy harvesters.

The transceiver consists of a novel phase-tracking RX, a digital TX based on an all-digital PLL (ADPLL) and a PHY-layer digital baseband. A hybrid loop filter enhances interference tolerance, in conjunction with precise frequency control enabled by the ADPLL. The receiver fronted achieves a sensitivity of -95dBm, while consuming only 2.3mW (non-duty-cycled) at 0.8V. The transceiver chip is implemented in 40nm CMOS, with a core area of only 0.8mm², including on-chip matching.

“This world-class BT5/BLE transceiver for IoT applications is the result of a successful collaboration with Renesas,” commented Kathleen Philips, Programme Director at imec/Holst Centre for IoT. “We are constantly looking for ways to improve battery lifetime of IoT sensors and radios and a low supply voltage is yet another key element in the roadmap towards successful IoT radio solutions.”

“Renesas has been producing high-performance devices leveraging low-power wireless communication technology, which will play a key role for expanding the upcoming wireless IoT business moving forward,” said Shin Saito, Senior Director, Industrial Analogue & Power Business Division, at Renesas. “Renesas believes that by jointly developing with Imec, we can achieve a more innovative system architecture, enabling a further leap for ultra-low power wireless technology and the wireless IoT market.”