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.Ī good MOSFET driver circuit has the following requirements:ġ.
How MOSFETs and Field-Effect Transistors Work! will all affect the switching performance of MOSFET. For a certain MOSFET, its drive circuit, the peak output drive current, the rising rate and etc. We should take a closer look at its own parasitic parameters. Such a circuit designed in this way is far from being a good circuit. We always only taking these factors into consideration. When using a MOSFET to design a switching power supply, most people will consider the parameters of on-resistance, maximum voltage and maximum current of the MOSFET. Let's discuss the drive circuits of MOSFETs for switching power supplies. The MOSFET often selects a appropriate driver circuit based on the parameters of the power-supply IC and MOSFET. MOSFET s are widely used in switching power supplies due to their low internal resistance and fast switching speed. Topics covered in the book include the state-of-the-art of power MOSFET drive techniques, the switching loss model, current source gate drivers (CSDs), resonant gate drivers, adaptive gate drivers and GaN HEMT gate drivers. If the parasitic capacitance of the selected MOS transistor is large and the driving capacity of the power-supply IC is insufficient, the totem pole circuit is often used to enhance the drive capability of the power supply IC, which is shown in the dotted box of figure 2. When the switching transistor is turned on, the drive circuit should be able to provide a large enough charging current to rapidly increase the voltage between the gate and source terminals of the MOSFET to the required value, ensuring that not only the switching transistor can be quickly turned on but also there is no high-frequency oscillation on the rising edge. The author perfected the content of this article on December 26th
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