BLE RF transceiver technology simplifies board design and increases power efficiency

Renesas Electronics Corporation develops two 2.4GHz RF transceiver technologies that support the Bluetooth LE low-power, near-field communication standard. The new technologies also fulfil a smaller mounting area and better power efficiency.

As well as being compact, low cost, and power-efficient, IoT devices must offer flexible support for Bluetooth LE regardless of their implementation format. The company has developed two new technologies to meet these demands: a matching circuit technology that covers a broad impedance range and allows the IC to match various antenna and board impedances without an external impedance-matching circuit; and a signal correction technology for locally generated reference signals that utilise a small circuit to self-correct inconsistencies in the circuit elements and variations in surrounding conditions without calibration.

The company has verified the effectiveness of these technologies on a Bluetooth LE RF transceiver circuit prototype built with a 22nm CMOS process. With these new technologies, it reduced the circuit area, including the power supply, to 0.84mm2, the world’s smallest for a device of this type. This was accomplished by modifying the receiver architecture to lower the number of inductors and enhancements, including a low-current baseband amplifier with a small mounting area and a highly efficient Class-D amplifier. They offer best-in-class power efficiency, with power consumption of 3.6mW and 4.1mW during reception and transmission, respectively. These advances enable smaller size, reduced board cost, and lower power consumption while simplifying the board design process.

These technologies apply to different RF transceivers and Bluetooth LE, and Renesas is currently working on practical applications for these technologies.