Sensor nodes used in Internet of Things (IoT) are required to work extremely long time without replacing battery. Natural renewable energy such as a solar battery is a hopeful candidate for such nodes. Here, an energy model for operating an SOI (Silicon on Insulator) device with a solar battery including a large inner resistance is proposed, and applied to a micro-controller V850E-star and an accelerator CMA-SOTB2. Unlike the ideal case, the maximum operational frequency was achieved with a relatively strong reverse bias (from -1.2V to -0.6V), since the increasing leakage current degrades Vdd . It appears that under the room light with a large inner resistance, the strong reverse bias is effective. With the bright light, a relatively weak reverse bias is advantageous. The proposed model is appeared to be useful to estimate the appropriate body bias voltage both for V850E-star and CMA-SOTB2. In the V850E-star the absolute values were different from the real chip, while they were well matched when CMA-SOTB2 was used under the low illuminance.
|ジャーナル||IEEE Transactions on Multi-Scale Computing Systems|
|出版物ステータス||Accepted/In press - 2018 4 16|
ASJC Scopus subject areas
- Control and Systems Engineering
- Information Systems
- Hardware and Architecture