The role of resistor in the circuit is very clear to us, but the noise of resistance is a problem that we can not ignore. In many high-end precision equipment, the noise of resistance becomes a bottleneck restricting the development of resistance. In many radar equipment and audio equipment, the noise requirement of precision resistor is very high, and the related instruments can not work properly if the noise is too big.
 

 

When there is a DC current passing through the non-wirewound resistor in the circuit, there is a so-called current-noise electromotive force which is different from the thermal noise. The current-noise EMF of the resistor is approximately proportional to the DC voltage at both ends of the resistor, while the power spectral density is inversely proportional to the frequency. In order to measure the electromotive force of the current noise, the system noise must be measured, as it is difficult to eliminate the thermal noise of the measured resistor and the interference of the internal noise of the amplifier to the current noise measurement.

The noise of resistance is related to many factors, such as current noise electromotive force, the material, technology, etc. Many R & D resistance companies have different design schemes to solve the problem of resistance noise. At present, the noise of high precision resistors will be reduced to a certain level by many big brand resistance manufacturers, and is developing different resistors for different industries.

 

 

At present, many resistive noise measuring devices can measure the resistance noise. By measuring the current noise and other data information of the active resistance, the measured data can accurately feedback the performance of the resistor. On the other hand, the size of the resistor noise also reflects the industrial level of the resistor. In contrast, the noise of the high-end precision resistor is very much smaller than that of the traditional resistor. They are well disposed in technology, material and structure.