1. Politecnico di Torino,Dept. of Electronics and Telecommunications (DET),Torino,Italy
2. Fed. Univ. of Rio Grande do SuI,Electr. Eng. Dept., Graduate Program in Microelectronics,Porto Alegre,Brazil
3. State-Key Laboratory of Analog and Mixed-Signal VLSI and IME/ECE-FST, University of Macau,Macao,China
4. University of Brescia,Department of Information Engineering,Brescia,Italy