A subthreshold-leakage suppressed switched capacitor (SC) circuit based on super cut-off CMOS (SCCMOS) scheme is introduced. This scheme realizes low-voltage SC circuits using low threshold voltage (VTH) transistors which are superior in drivability and are compatible with digital circuits. The SC circuit cannot be operated under 0.5V with high-VTH devices but on the other hand, SC circuits with low-VTH transistors suffer from charge loss even in analog operations. A 0.5-V sigma-delta modulator with the proposed scheme is successfully manufactured and measured by using 0.15-µm FD-SOI process with 0.1-V VTHN transistors.
K. Ishida, K. Kanda, A. Tamtrakarn, H. Kawaguchi,