Noise Measurement System Based on Cross-Correlation Method

High precision electronic applications require low noise devices in order to increase the resolution and stability of measurement equipment. All resistors generate thermal noise and low frequency noise that is highly dependent on the technology used to manufacture these components and the current flowing through them. This paper presents a low noise measurement system, based on cross-correlation method. The noise measurement system was applied for metal film resistors. Using cross-correlation, the noise introduced by the amplifiers is reduced significantly. The noise spectra were measured at room temperature in a frequency range from 0.5 Hz to 10 kHz. The results show that the equivalent input voltage noise of the system is 2 nV/vHz at 1 Hz and 0.53 nV/vHz for frequencies above 100 Hz. The resistor noise components, thermal and low frequency noise were identified by measuring the voltage spectral density for different bias voltages. The obtained data validated the system's effectiveness.