MOSFET 1/f noise measurement under switched bias conditions

Abstract—A new measurement setup is presented that allows the observation of 1 noise spectra in MOSFET’s under switched bias conditions in a wide frequency band (10 Hz–100 kHz). When switching between inversion and accumulation, MOSFET’s of dif-ferent manufacturers invariably show reduced 1 noise power density for frequencies below the switching frequency. At low fre-quencies (10 Hz), a 5–8 dB reduction in intrinsic 1 noise power density is found for different devices, largely independent of the switching frequency (up to 1 MHz). The switched bias measure-ments render detailed wideband 1 noise spectra of switched MOSFET’s, which is useful for 1 noise model validation and analog circuit design. Index Terms—1 noise, MOSFET LF noise, noise reduction, switched bias. I