MOSFET driver is a high-frequency and high-voltage gate driver that can drive two N-channel MOSFETs using a synchronous DC/DC converter and a power supply voltage of up to 100V. The powerful driving capability reduces the switching losses in MOSFETs with high gate capacitance. Configure for two inputs that are not related to the power supply. The input logic signal on the high-voltage side is internally shifted to a bootstrap power supply, which can operate under voltage conditions up to 114V above ground.
MOSFET, also known as field-effect transistor, has a high input resistance and is easy to drive in the megaohm range. It is widely used in switching power supplies due to its low internal resistance and fast switching speed. When using MOSFET to design switch mode power supplies, most people consider conduction resistance, maximum voltage, and maximum current, and often choose the appropriate circuit based on the parameters of the power supply IC and MOSFET. But often, only considering these factors is not a good design solution, and one should also consider the parasitic parameters themselves. The MOSFET switching performance is affected by the peak current output from the MOSFET driver circuit, the rate of rise, and other factors.
Five requirements for MOSFET driver circuits:
1. When the switch is turned on, the driving circuit should be able to provide sufficient charging current to rapidly increase the MOSFET gate source voltage to the desired value, ensuring that the switch can be quickly turned on without high-frequency oscillations on the rising edge.
2. During the switch conduction period, the driving circuit can ensure stable and reliable conduction of the MOSFET gate source voltage.
3. The turn-off moment driving circuit can provide a path with the lowest possible impedance for the rapid discharge of the capacitance voltage between the MOSFET gate source electrodes, ensuring that the switching transistor can be quickly turned off.
The 314 series optocouplers are very suitable for driving power inverters, inverters for motor control, and MOSFETs. It includes an LED optically coupled to an integrated circuit with a power output stage. The optocoupler ensures its operating parameters within the temperature range of -40 ° C to+110 ° C.
Optocoupler is one of the rings in optoelectronic devices, which is a combination of light-emitting and light-receiving components. It achieves the requirement of conductivity through the transmission of light and is an ideal insulator. Therefore, in many electronic and electrical products, this device is used for high-voltage isolation. Light emitting devices are usually light-emitting diodes, while light-receiving devices are typically photodiodes/transistors/thyristors in lower order products, and optocouplers in higher-order products.
Characteristics of optocoupler TD314:
Maximum peak output current of 1.0A
Rail to rail output voltage
110ns maximum propagation delay
Low voltage lockout protection with hysteresis phenomenon (UVLO)
Wide working range: 10 to 30 volts (VCC)
Ensure performance exceeds temperature range of -40 ° C to+110 ° C