Advantage
- Reduced power consumption to the world’s lowest level
- Noise rejection characteristics (PSRR) equal to or better than conventional technology
Background and Technology
Associate Professor Daisuke Kanemoto at the Graduate School of Engineering, Osaka University, have been researching low-power, high-performance wireless communications based on compressed sensing and developing wearable devices that use this communication technology. In this presentation, Kanemoto et al. will introduce their low dropout (LDO) regulator technology that achieves both extremely low power consumption and high performance.
An LDO regulator is a part of DC power supply system, such as a battery, and has the function of removing noise and other elements from the power supply signal processed by the DC/DC converter. The performance of noise rejection is called PSRR (Power Supply Rejection Ratio), and there is generally a trade-off between PSRR improvement and low power consumption. The fields of IoT and wearable devices and medical equipment require that LDO regulators have very low power consumption. On the other hand, LDO regulators are also required to have low noise when used as power supplies for sensor modules that acquire weak signals and RF modules that control wireless communication functions.
Dr. Kanemoto of the Graduate School of Engineering, Osaka University, has independently developed an LDO regulator circuit that operates with extremely low power consumption. It is important to increase the gain of the open-loop transfer function in the LDO regulator circuit to improve PSRR. General PSRR improvement measures use high-bandwidth differential amplifiers to achieve high gain over a wide range of frequencies to improve PSRR, which tends to increase power consumption. On the other hand, the technology proposed here is an original technology that utilizes a Flipped Voltage Follower (FVF) and a source ground amplifier circuit. Since this circuit has no extra amplifier, it can suppress power consumption to the utmost limit. In addition, it can achieve high PSRR in frequency bands where noise is likely to be introduced. Even if the PSRR of the LDO regulator of this technology is the same level as existing products, its power consumption is equal to or lower than the smallest case of commercially available LDO regulator products, and is less than microamperes (verified by computer simulation).
This technology is expected to be applicable to high-performance power supplies for IoT sensors and wearable devices in a wide variety of applications, as well as in terms of energy harvesting.
Expectation
Osaka University proposes to commercialize low drop-out regulator products based on this technology, as well as joint development and development assistance for IoT sensors and wearable devices.
We can provide the technology to companies interested in commercializing this technology as discrete products through patent licenses and other means.
We can also provide joint device development assistance to companies developing IoT sensors and wearable devices if they are having trouble achieving both PSRR and low power consumption.
We can help promote unprecedented cost reduction in wearable devices such as wireless earphones, cameras, and smart glasses, medical devices for healthcare monitoring, and IoT edge devices used in industry, agriculture, and infrastructure.
Patent
Applied in Japan. Osaka University plans to file a PCT application for this technology.
Researcher
Associate Professor Daisuke Kanemoto, the Graduate School of Engineering, Osaka University
Project No: DA-04138