Low-frequency noise properties of dynamic-threshold (DT) MOSFET's

This paper shows that MOSFET operated in dynamic-threshold (DT) mode (V/sub body/=V/sub gate/) is more suitable for low-noise RF/analog applications than those operated in conventional mode (V/sub body/=V/sub source/). Detailed low-frequency noise properties of these two modes of device operation were compared for 0.31-μm gate MOSFET's, in which NMOS's are surface-channel devices (S.C.) and PMOS's are buried-channel (B.C.) devices. Experimental data show that when the devices are biased at same transconductance, the low-frequency noise in DT mode is 30 times lower (at g/sub m/=2.2×10/sup -3/ S) than that in the conventional mode for the B.C. devices and ten times (at g/sub m/=2.0×10/sup -3/ S) lower for the S.C. devices.