The meaning of parasitic is that there is no capacitance designed in that place, but because there is always mutual capacitance between wiring, mutual capacitance is like parasitic between wiring, so it is called parasitic capacitance, also called stray capacitance.
1. On the other hand, in addition to the capacitance between the plates of the sensor, the plate and the surrounding body (various components and even the human body) also have a capacitive connection. This kind of capacitance is called parasitic capacitance. It not only changes the capacitance of the capacitive sensor, but also because the capacitance of the sensor itself is very small, the parasitic capacitance is extremely unstable, which also leads to unstable sensor characteristics and serious interference to the sensor.
2. Distributed capacitance between the wires, between the coil and the casing, and between some components. These capacitances are called parasitic capacitances. Although their values are small, they are an important cause of interference.
Due to the continuous increase of frequency, the influence of lead parasitic inductance and parasitic capacitance has become more serious, causing greater electrical stress (in the form of overvoltage and overcurrent burrs). In order to improve the reliability of the system, some manufacturers have developed a “user-specific” power module (ASPM), which installs almost all the hardware of a complete machine into a module in the form of a chip, so that the components are no longer With traditional lead connections, such modules have undergone strict and reasonable thermal, electrical, and mechanical design to achieve a perfect state of optimization. It is similar to the user-specific integrated circuit (ASIC) in microelectronics. As long as the control software is written into the microprocessor chip in the module, and then the whole module is fixed on the corresponding radiator, a new switching power supply device is formed. It can be seen that the purpose of modularization is not only to facilitate use and reduce the size of the whole machine, but more importantly, to cancel the traditional connection and minimize the parasitic parameters, thereby minimizing the electrical stress on the device and improving the reliability of the system.