Internet of things (IoT) is a prevailing concept that enables the interconnection between the daily objects and the cloud server to provide quality lives. Two major IoT applications are the smart green building (SGB) and the implantable medical device (IMD). The former is powered by energy harvesting technique while the latter is powered by wireless power transferring technique. Both techniques require efficient power management circuits to prolong the battery life. This thesis targets at power delivery systems for the above two applications and is divided into three parts.

The first design is an inductor-shared multi-input and multi-output switched-mode DC-DC converter for SGB application. It can intake three energy harvesters as sources and generate three output rails for loading sen...[ Read more ]

Internet of things (IoT) is a prevailing concept that enables the interconnection between the daily objects and the cloud server to provide quality lives. Two major IoT applications are the smart green building (SGB) and the implantable medical device (IMD). The former is powered by energy harvesting technique while the latter is powered by wireless power transferring technique. Both techniques require efficient power management circuits to prolong the battery life. This thesis targets at power delivery systems for the above two applications and is divided into three parts.

The first design is an inductor-shared multi-input and multi-output switched-mode DC-DC converter for SGB application. It can intake three energy harvesters as sources and generate three output rails for loading sensors. It is designed to be a general-purposed power platform, which has wide power and voltage ranges. To enhance the efficiency over the power range, a burst-mode clock scheme is proposed. To enhance the efficiency over the voltage range, an optimal switch size tracking scheme is proposed.

The second design is a low power relaxation oscillator, which is an important submodule for the power supply system. A frequency-locked loop (FLL) is proposed to stabilize the frequency against PVT variations. Meanwhile, a current-injection compensation scheme is proposed to compensate the temperature shift of the on-chip resistors.

The third design is a full-bridge class-D power amplifier (PA) for IMD application. It converts DC power into AC power, which wirelessly supplies the implanted secondary chip via an inductive-coupled link. A fractional-capacitance auto-tuning loop (ATL) is proposed to tune the primary LC tank's resonant frequency to PA's driving frequency automatically. As a result, the link voltage gain is improved so as to increase the transfer distance. The PA's efficiency is also improved due to PA's zero-current switching. To improve the tuning accuracy, delay compensation and synchronizing schemes are also proposed.