1. Zhejiang University,Institute of VLSI Design,Hangzhou,China,310027
2. Zhejiang University,Department of Biomedical Engineering & Instrument Science,Hangzhou,China,310027
3. Zhejiang University,Micro-Nano Fabrication Center,Hangzhou,China,310027
4. University of Macau,State-Key Laboratory of Analog and Mixed-Signal VLSI and IME/ECE-FST,Macao,China