New Industry Products

MCUs Extend Battery Life and Simplify Antenna Circuit Design

July 16, 2015 by Jeff Shepard

Renesas Electronics today announced a new wireless solution that supports the Bluetooth® Smart near field wireless communication standard. The new RL78/G1D Group of microcontrollers (MCUs) has been developed by combining the low-power RF Transceiver Technology for Bluetooth® Low Energy (BLE), which the company presented at the International Solid-State Circuits Conference (ISSCC) held in February, 2015, with Renesas' expertise on consumer and industrial MCUs, and on-chip peripheral devices necessary for wireless communication.

By employing an evaluation kit and Bluetooth-SIG qualified protocol stack, the new MCUs enable system designers to conduct evaluation of wireless characteristics and initial evaluation of communication behaviors. The new MCUs are also provided with PC GUI tool for easy manipulation of these components. These will enable customers to easily develop Bluetooth Smart applications and reduce the time required for development while making effective use of development environment and software resources.

The current consumption of the RL78/G1D is among the lowest in the industry (3.5mA during reception and 4.3 mA during transmission), delivering substantially reduced power consumption that is a key consideration for wireless devices. A newly added adaptable RF technology adjusts the power consumption during wireless operation to the optimal level to match the communication distance. This dramatically lowers the power consumption of near field wireless communication, and it is complemented by the on-chip integration of most elements required for the antenna connection, contributing to reduced external component costs.

Key features of the new RL78/G1D MCUs: On-chip balun elements required for antenna connection simplify antenna connection circuit design; The new RL78/G1D integrates on-chip the balun elements that otherwise would have to be provided in an external antenna connection circuit. This makes it possible simply to connect the RF transceiver signal terminals to the external antenna terminals without the need for discrete balun elements. This eliminates the need to perform repeated matching adjustment and evaluation on a balun circuit, thereby saving on development costs. In addition, the components of the balun circuit do not have to be provided externally, lowering both the product cost and component management costs. Thus, production costs are reduced as well.

Industry-leading low current consumption for extended battery life; The newly developed low-current-consumption on-chip RF transceiver supports version 4.1 of the Bluetooth Core Specification and enables wireless operation at among the lowest power consumption levels in the industry (3.5 mA during reception and 4.3 mA during transmission, at 0 dBm). This, combined with the excellent power efficiency of the RL78 family of ultra-low-power MCUs, makes for extended battery life. For example, when wireless communication takes place at one-second intervals while maintaining a connected state with another wireless device, the BLE functionality can be added with the industry-leading low average current of 10 µA.

Function that automatically optimizes power consumption during wireless operation to match communication conditions; Built-in adaptable RF functionality optimizes the power consumption during wireless operation to match the communication distance. This prevents more power than necessary from being used, especially during near field communication. By using this functionality, under communication conditions where the wireless devices are located approximately 1 meter apart (varies according to the connection status) and when the frequency of wireless operation are raised in order to prioritize data transfer, it is possible to boost power efficiency.

The new RL78/G1D Group comprises of six product versions - 256, 192 & 128 KB on-chip flash memory options and industrial or consumer grade for each memory option. Samples are available now. Mass production is scheduled to begin in October 2015 and is expected to reach a combined volume of 1,000,000 units per month in 2016.