Mosfet High Side Switch Circuit

That s creating a low side switch.

Mosfet high side switch circuit.

While designing the ups circuits mosfet were used in the inverter circuits. N channel p channel 15. Firsly in fig 4 6 13 the resistor r4 whose purpose is to discharge any remaining potential on the gate at switch off is now connected to the positive supply rail instead of to ground. For driving the mosfet in high side configuration ir2110 gate driver ic was used.

While you can use a jfet for this circuit an enhancement mode mosfet works better. My logic is that since it is a series circuit the mosfet should handle the current whether the load was in the source or in the drain. One fault common to such circuits has been the excessive crossover current during switching that may occur if the gate drive allows both mosfets to be on simultaneously. The opposite of the low side switch is the high side switch.

Notice the similarities and differences between figs. This transistor connects between v and the load. In a p channel device the conventional flow of drain current is in the negative direction so a negative gate source voltage is applied to switch the transistor on. I ve written a detailed tutorial regarding the use of ir2110.

A high side p channel mosfet and a low side n channel mosfet tied with common drains figure 5 make a superb high current ªcmos equivalentº switch. The mosfets were used as high side switches in the circuit. Ir2110 which is arguably the most popular high low side mosfet driver features a high side driver and a low side driver in a single device. However it just comes down to the voltage difference between gate and source.

Ir2117 for example is one driver that contains a single driver that can be used to drive a high side mosfet driver. Usually a p channel will be configured as a high side switch as i show here. In this instance the mosfet switch is connected between the load and the positive supply rail high side switching as we do with pnp transistors. A circuit for a typical high side switch using a p channel mosfet is shown in fig.