LiDAR

LiDAR(Light Detection And Ranging) is attracting a lot of attention as it’s installed in the latest high-end smartphones and cars. The LiDAR sensors, which can detect both short and medium distances, are large-scale in aviation, space, and other applications, as well as smartphones and automobiles. A LiDAR sensor, such as a ToF(Time-of-Flight) sensor, comprises a transmitter equipped with optics and a receiver, measuring the time-phase difference from the reflected return signal after illuminating the target with an optical pulse emitted by the Vertical Cavity Surface Emitting Laser (VCSEL). In our lab, we focus on both the transmitter (TX) and receiver (RX) aspects of LiDAR sensors. For the TX component, we are studying a high-output precision VCSEL driver. This driver includes pre-emphasis to manage driving significant current at high speed. Regarding the RX, our research involves a high-performance APD/SPAD read-out circuit, such as the TDC(time-to-digital converter)/TAC(time-to-amplitude converter) IC. Furthermore, we are developing mutual interference rejection technology among different LiDAR systems to ensure stability. Additionally, a multi-event detection technology is being designed to further enhance the reliability of the LiDAR system.

Power Management ICs

Power management IC(PMIC) has emerged as a very important part of the efficient management of restricted battery resources to meet multi-functional, high-performance systems and different service requirements. Input-to-output voltage regulators, such as low dropout regulators (LDO) and DC-DC converters an essential circuits of PMIC. With the increase in the mobile application markets, recent technology is toward minimizing or eliminating discrete elements such as inductors or capacitors that are used in the regulator. The DC-DC converter is required to not only maximize the power transfer efficiency but also minimize the switching loss because the switching frequency increases to minimize discrete elements. In the case of LDO, it is required to improve the power supply rejection ratio(PSRR) and transient response to minimize the output capacitor, so that it can be implemented in the chip. In our lab, we focus on researching analog and digital LDO regulators, as well as DC/DC converters. These are designed for high PSR, rapid transient response, and an Active DVS (Dynamic Voltage Scaling) system, enabling precise control over local hot spots to achieve optimal efficiency.

Sensors

Adaptive front lighting system (AFS) driver IC optimizes the driving experience under harsh environmental and traffic conditions. The driver IC uses regulators with temperature-independent current control for constant brightness. The maximum current error of 4.11% at 100 °C is reduced to 0.23% with the temperature compensation. The proposed driver utilizes PWM to calibrate the power of the heater for constant power and heat. The temperature in each heater is well under control within 1.31% even though 16.07% mismatch of heater resistance. In our laboratory, we conduct research on various drivers for μAFS, as well as temperature and several sensors with temperature calibration or optimization to address cell uniformity and error correction relative to ideal values.

Automotive Applications

Limited driving range, high costs, and battery safety issues are the main challenges for battery electric vehicles (BEVs). In addition, there are issues with various power semiconductors and other devices. So, there are some high hurdles to overcome in terms of reliability, qualification, and functional safety. and there are some relatively high-cost pressures In our lab, we research an EIS(Electrochemical Impedance Spectroscopy) system for BMS(Battery Management System) and DC-DC converter, an On-road Dynamic pattern projection system designed to enhance the efficiencies in Automotive Applications.