Research

Our group will focus on a range of perspectives dealing with different circuit topologies, devices, and architectures in order to break through the current technologies in the field of: 

• Power Management Integrated Circuits for mobile systems;

• High Voltage Power Electronics Circuits for automotive/industrial applications;

• Energy efficient integrated circuit designs;

• RF power amplifiers for next generation communications

– Power Management ICs for Battery Quick Charger and Mobile Applications

Advanced Battery Quick Charge technology becomes crucial for speed-up charging time as well as cooling down the system. Unlike conventional power conversion topology, our group is exploring a novel concept of charger IC design to implement a highly efficient charging system to fulfill the requirement of future charging technology.

Prof. Kunhee Cho was in charge of Qualcomm Quick Charger IC design from 2017 to 2020 at Qualcomm, Santa Clara, CA, USA, and now leads his group to investigate advanced charger ICs design.

• Highly efficient battery charger ICs to support quick charge technology;

• Smart charger to support both 1-cell and 2-cell batteries for universal applications;

• Hybrid DC-DC converters to system power supply.

• #Switching Charger #DC-DC converter #Hybrid power converter #Built-in-resistance (BIR) sensing #Battery cell balancing

– High-Voltage Power Electronics Circuits for Automotive/Industrial Applications

The market of HV ICs for industrial applications is growing fast because of demanding for smart homes, consumer electronics, and electric vehicles. In recent days, SiC and GaN show superior figure of merit (Rds.on x Qg) over MOSFET and IGBT which have a huge benefit on high-voltage high-speed switching operation. Our group is employing these devices in the power management circuits can have advantages for reducing size as well as improving thermal effect while output power remains consistent.

Prof. Kunhee Cho was in charge of 650V High Voltage Gate Driver IC design and 100-230Vac LED Driver IC design from 2009 to 2012 at Fairchild Semiconductor (Currently, ON Semiconductor), Korea, and now leads his group to investigate advanced high voltage power electronics system design.

• Highly voltage gate driver ICs with high switching frequency to drive wide-bandgap power semiconductor;

• LED drivers for universal LED lighting applications.

• #Galvanic Isolation Gate Driver #Junction Isolation Gate Driver #GaN #SiC #AC-DC Converter #DC-DC Converter

– Energy Efficient Integrated Circuit Designs

Recently, computing-in-memory (CIM) has been employed in low-power machine learning (ML) / artificial intelligence (AI) SOCs due to their ultra-high computing efficiency. The CIMs pose challenges for the trade-off between energy efficiency and overall system performance, and the advanced integrated circuit designs are highly desirable to break through this issue. Therefore, our group is discovering advanced analog/mixed integrated circuit designs to provide adequate power and clock requirements for AI systems.

• Advanced integrated circuits for the AI systems;

• Supporting the supply voltage and clock requirements of the system simultaneously to maximize their performance.

• #LDO #Dynamic Voltage Frequency Scaling (DVS) #Distributed Power Grid #PLL #XO Driver

– RF Power Amplifier (PA) Design for Next Generation Communications

RF PA is one of the most power-hungry devices in the communication system. Today, Since, advanced communication standard needs to support higher data rate, highly efficient RF PA is required to achieve high efficiency in large PAPR modulated signals. In addition, PA implementations are challenging due to the requirements for high breakdown voltage and high output power. Our group is exploring digitally intensive switching PAs because they have better efficiency compared to linear PAs and also allow for the utilization of deep submicron CMOS technologies.

• Switching PAs : RF-PWM PAs, RF-DAC PAs, switched capacitor PAs, Outphasing PAs.

• #RF PA #Class-D PA #Class-G PA #RF-FAC