A novel ultra low-leakage switch for switched capacitor circuits

The voltage drop rate in switched capacitor circuits is typically limited by OFF state of switch. Past low-leakage switch designs have assumed that subthreshold conduction and drain-to-bulk diode leakage dominate over other leakage sources. However, recent researches revealed a third important mechanism, accumulation-mode source-drain coupling, which can contribute significant leakage. This paper presents a novel switch, which minimizes the overall effect of these three leakage sources. Therefore, it is proper for high-accuracy switched-capacitor circuit applications. This switch has been simulated in 0.35-μm CMOS technology. At 3.3-V power supply, 22.07-pW total power consumption and 337-aA maximum leakage current were obtained.