Mosfet Load Switch Circuit

The pass transistor and the on off control block as shown in figure 1.

Mosfet load switch circuit. Load switches are placed in series with the voltage source and the load. The circuit to turn off elements is referred to as a load switch. This also allows for the mosfet s gate drive or switching signal to be referenced to ground low side switching. Now that we have hooked up sufficient voltage to the gate to turn on the transistor then we must supply voltage to our load on the source terminal of the transistor.

When the load is connected at the source side the vgs will needs to be higher in order to switch the mosfet. The mosfet switch circuit load in this case is a 12v 36watt automotive headlamp bulb and the input to the mosfet switch will be a pulse width modulated logic level signal. This may be supplied by any 5v compatible logic circuit producing a pwm signal at a frequency in the high audio frequency range. A basic load switch such as the nx3p190 from nxp figure 3 resembles the circuit in figure 1 it has the p channel mosfet controlled by a level shifting and slew rate control circuit.

Mosfet works in three regions cut off region triode region and saturation region. Hi this information is helpful for me. Mosfet passes the voltage supply to a specific load when the transistor is on. A load switch is comprised of two main elements.

When the mosfet turns on inrush current irush flows to charge this capacitor. How much voltage do i need to turn on the mosfet. But when using mosfet as a switch either with inductive load or capacitive load then protection is required for the mosfet device. I want to ask.

In most of the cases n channel mosfets are preferred. Thus far we have looked at the n channel mosfet as a switch were the mosfet is placed between the load and the ground. When mosfet is in cut off triode region it can work as switch. Power amplifier display asic logic load switch load switch load switch load switch voltage source power management fig.

The application is shown in fig. In example i have 12v dc with irf n channel type logic level mosfet and the load connected on the source side. This inrush current is reduced by increasing the series gate resistor rgate. In the above circuit it is a very simple circuit for switching a resistive load such as a lamp or led.

Load switch options the many possible applications for load switches let the load switch manufacturers offer multiple load switch configurations. The typical load switch shows in fig. Mosfet switching circuits consists of two main part mosfet works as per transistor and the on off control block. The following figure is a circuit diagram showing the use of a mosfet as a load switch.