Analog T-switch scheme is introduced to suppress subthreshold-leakage problems in charge-based analog circuits such as switched capacitor and sample and hold circuits. A 0.5-V sigma-delta modulator is manufactured in a 0.15-/spl mu/m FD-SOI process with low V/sub TH/ of 0.1V using the concept. The scheme is compared with another leakage suppressed scheme based on super cut-off CMOS (SCCMOS) and the conventional circuit which are also fabricated. The sigma-delta modulator based on analog T-switch realizes 6-bit resolution through reducing nonlinear leakage effects while the conventional circuit and the scheme based on SCCMOS can achieve 4-bit and 5-bit resolution, respectively.