When MOS is turned on and off, it must not be completed in an instant. The voltage at both ends of the MOS has a falling process, and the current flowing through it has a rising process. During this period, the loss of the MOS tube is the product of the voltage and the current, which is called switching loss. Usually switching losses are much larger than conduction losses, and the faster the switching frequency, the greater the losses.

There are a number of pumps used in automotive applications, such as fuel, water and air pumps. Both brushed and brushless DC motors can be suitable for this application. For the former a simple half-bridge structure can be used ( Fig. 14). In some small current load applications, the recirculating FET can be replaced by a Schottky diode. For brushless motor a more comple structure of 3-phase bridge is required Fig. 13. In this case the difference in complexity and number of components can be quite stunning. Wide range of interesting constantly updated game mods, allowing users to reach as much additional functions as possible. Lastly, another important parameter was the viscous drag which was found to be approximately 0.0001 Nm/(rad/s). At this stage the motor was characterised and thus expected to behave as the real one presented in the technical note TN90002. newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\) MOSFET s are widely used in switching power supplies due to their low internal resistance and fast switching speed. The MOSFET often selects a appropriate driver circuit based on the parameters of the power-supply IC and MOSFET. Let's discuss the drive circuits of MOSFETs for switching power supplies.In modern automotive applications, an average of about 30 relays are used in a car. Driving a relay is simple, and the internal resistance of the connection can be very low. However, compared with relays, MOSFETs have obvious advantages in noise, service life, miniaturization and reliability. Therefore more and more manufacturers consider using MOSFETs to replace relays. Because of the high input impedance of the MOS transistor gate, a little static electricity or interference may cause the MOS transistor to be misconnected. Therefore, it is recommended to connect a 10K resistor in parallel between the MOS transistors G and S to reduce the input impedance. If you are worried about the interference coupling on the nearby power line, which will cause instantaneous high-voltage breakdown of the MOS tube, you can connect a TVS transient suppression diode of about 18V in parallel between GS. TVS can be considered as a voltage regulator tube with fast response speed. The power it can withstand instantaneously is as high as several hundred to kilowatts, which can be used to absorb instantaneous interference pulses. For this particular motor the rotor was measured to weigh 220 g and to have a radius of approximately 17 mm, thus yielding an approximately 3.15x10 -5 kg·m 2 moment of inertia. Additionally the plastic disc was found to have a moment of inertia of approximately 3.5x10 -6 kg·m 2. By adding the two, the total inertia was found to be 3.5x10 -5 kg·m 2.

The rotor dimensions were measured and by approximating its shape to a cylinder its moment of inertia was found using Eq. 4 where m = rotor mass and r = rotor radius: The semiconductor should be uniformly doped with donors or acceptors as p-type or n-type semiconductors. When the power-supply IC and MOS transistor are selected, it is especially important to select an appropriate driver circuit to connect the IC to the transistor. We also offer automotive qualified gate driver ICs. The trend towards greater efficiency in automotive applications also concerns electric motors. Applications such as power steering, HVAC compressors and engine cooling fans will be controlled by electronic motors in the future. The configurable, H-bridge and three-phase automotive gate driver IC's can be combined with automotive MOSFETs to provide the power and efficiency these systems demand.MOSFET is a type of FET, which can be made into enhancement mode or depletion mode, P-channel or N-channel, a total of 4 types, but only the enhancement-mode N-channel MOS tube and the enhancement-mode P-channel are actually used. MOS tube, so NMOS is usually mentioned, or PMOS refers to these two. For these two enhanced MOS tubes, NMOS is more commonly used. The reason is that the on-resistance is small and it is easy to manufacture. Therefore, in the application of switching power supply and motor drive, NMOS is generally used. In the following introduction, NMOS is mainly used.