Chip resistors for noise in power circuits

We often find various ripple currents when testing circuit boards. Most of these ripples are caused by the unstable components of the circuit itself. We call this phenomenon ‘noise’. Nowadays, the key role of people is the chip resistor. Yes, chip resistors can also cause "noise" after being plugged in.

So how can such a stable current-limiting device produce noise? Let's take a look at the source of the chip resistor noise.

There are two reasons for the noise caused by chip resistors. The first is that the amount of current caused by the heat generated by the chip resistor causes the metal powder particles coated on the surface of the chip resistor to cause an offset effect (that is, the energy is converted into mechanical energy), which causes a large change in the resistance value of some parts, which may cause the current to be unstable And ups and downs.

Second, due to the limitation of the chip resistor coating technology, the metal film on the surface of the chip resistor cannot achieve a complete and uniform distribution, and the resistance value of some parts is not completely the same. Therefore, when the current passes through the entire chip resistor, it suddenly increases and causes a certain The fluctuation of the noise will cause noise.

Although the current technical level cannot completely avoid the noise of chip resistors, the vacuum evaporation and sputtering technology of thin film resistors reduce the noise to a very small level, greatly improving the stability of chip resistors.