1. School of Integrated Circuits, Guangdong University of Technology, Guangzhou, China
2. School of Information Engineering, Guangdong University of Technology, Guangzhou, China
3. Department of Electrical and Computer Engineering (ECE), Institute of Microelectronics, State Key Laboratory of Analog and Mixed-Signal VLSI, Faculty of Science and Technology (FST), University of Macau, Macao, China