(Topics)
Energy harvesting technology
Semiconductor memory system
Analog circuit system
Power conversion system
The shipment volume of integrated circuits, such as IoT devices, AI-specific LSIs, and driver ICs for power semiconductors, continues to expand every year. As a result, the overall power consumption of integrated circuits is also consistently increasing. Low power consumption at both the circuit and system levels, in other words, greening, is becoming increasingly important. In our research laboratory, we are conducting research and development on technologies to green the circuit systems of digital, analog, memory, and power converter used in these LSIs.
Each lab member will have the opportunity to gain experience in circuit design (creating circuit diagrams, verifying operation with a circuit simulator, and designing layouts) as well as in the measurement and evaluation of prototype circuits and paper writing, as shown in Figs. 1, 2.
Let’s enjoy imagining circuit operation in a physical sense, quantifying characteristics with mathematical sense, and contemplating the greening of the system through overall optimization. If you are confident that you can continue what you are working on, you can do well enough in this laboratory.
Key Achievements
Power Converters for Energy Harvesting
| Energy transducer | Voltage up- or down | Nominal frequency | Contribution of Lab | ||
| DC | Photovoltaic | Up | DC | SC MPPT design | |
| Thermoelectric | SC MPPT design, mV boost converter SI Battery-assisted battery charger | ||||
| AC | Electromagnetic | 6M/13M for bio, 920M for WPT | SC Rectenna design for high sensitivity X-coupled CMOS charge pump model | ||
| Vibra-tion | Electromagnetic Magnetostrictive | 1-100Hz for EH | Clocked AC-DC charge pump | ||
| Piezoelectric | Up or down | Going to start | |||
| Electrostatic Triboelectric | Down | Shunt regulator with LV CMOS SC AC-DC converter | |||
Memory Design
| Word-line driver Pre-emphasis pulse generator 1, 2, 3 Charge pump High– / Low– level shifters | Memory cell array 3D NAND Temperature compensation Divided BL scheme |
| Controller Oscillator Error Correction Cap structure | Sense amplifier Low voltage differential amp Power reduction read scheme Pre-emphasis sensing |
