Toshiba Electronic Devices & Storage Corporation
The SoC realized the highest link budget with low power consumption
TOKYO--Toshiba Electronic Devices & Storage Corporation (“Toshiba”) today unveiled a Bluetooth® low energy System-on-Chip (SoC) for IoT devices compliant with Version 5.0 standard, that realizes a 113dB link budget, the highest yet achieved, and a high transmission power efficiency of 22%. These characteristics push the SoC’s long-distance communication to 600m, 4.6 times that of its predecessor  while cutting power consumption to about 70% that of standard products that support the same communication distance. Toshiba presented the technology at VLSI Circuits Symposium 2018, the international conference on semiconductor devices held in Honolulu, Hawaii on June 19.
Continued advances in IoT technology is bringing new capabilities to fields as diverse as wearable devices and medical equipment, and advanced functionality is taking more and more computing to the edge, particularly into industrial systems. Progress here is based on developing advanced functions. For instance wireless communication ICs must be able to deliver long-distance communications without consuming too much power. This is the need Toshiba addresses with its new SoC.
Bluetooth® low energy is the de facto standard for wireless communications. However, typical Bluetooth® low energy SoCs generate harmonic emission when output power increases, and can potentially violate Federal Communications Comission regulations. Additionally suppression of harmonic emission and efficiency is a trade-off that has made it difficult to achieve both long-distance communication and low power consumption.
Toshiba has developed two technologies for the power amplifiers of Bluetooth® low energy SoCs that minimizes the problem.
First, a new technology to enhance suppression of harmonic emission. This is usually done by symmetry feedback that extends to the drivers. However, this does not suppress harmonic emission generated in the final output from the power amplifiers. If symmetry feedback is applied, including in the final stage, it only results in further transient harmonic emission. Toshiba minimized this problem by adding a “presetter” that suppresses transient harmonic emission.
Secondly, Toshiba improved efficiency in the output stage of power amplifiers. This contains two switch transistors. When both are turned on, a large “through-current” flows, and power consumption increases. Toshiba developed a structure to separately control these switches, successfully suppressing through-current.
In combination, these technologies extend the communication range while suppressing harmonic emission and reducing power consumption.
Toshiba started to ship samples of Bluetooth® low energy SoCs compliance with Version 5.0 standard with the new technologies in January this year, and plans to start mass production in September. Toshiba continues to promote R&D in technologies for wireless communication ICs, and to contribute advances in IoT devices.
 Link budget refers to the difference between transmission power (in dBm) and the sensitivity of the receiver (in dBm). The larger the link budget means the further the communication.
 In Bluetooth® low energy SoCs compliant with version 5.0. As of January, 2018. Toshiba Electronic Devices & Storage Corporation
 TC35678, Toshiba Electronic Devices & Storage Corporation’s earlier product
 Symmetry feedback senses the asymmetry of waveform and then adjusts them to achieve symmetry.
 A presetter circuit in power amplifiers is set to a predicted convergence before symmetry feedback starts.
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