What is low side switching?

What is low side switching?

Low-side switching has one ground connection for both the load and its controller, thus avoiding ground potential differences (ground shifts) between the two when currents are high. Low-side switching therefore is more robust to ground noise than high-side switching.

What is a low side fet?

A low-side switch is a MOSFET or an IGBT that is connected to the ground-referenced and is not floating. In a boost converter, the source terminal of the MOSFET is connected to the circuit ground, which is referred to a low-side MOSFET.

What is low side Vs high-side?

High-Side vs. A low-side driver is placed between the load and ground, whereas a high-side driver, shown in 2(b), is placed between the load and the supply voltage. The low-side driver is often used for powertrain-related loads such as motors, solenoids, and heaters.

What does a low side transistor switch mean?

Low-side transistor configuration When the transistor is connected to ground, that means the load is between +V and the transistor. Since the transistor is switching the path to ground or is sitting on the low side of the load, it is called a low side switch. Typically these use an NPN BJT or an N-Channel MOSFET.

When to use high side or low side switch?

So when you have a load that requires ground, you NEED to use a high-side switch. As a quick rule of thumb, if you are turning a device on and off, a low-side switch is a simple solution. However, if you are delivering power to an entire circuit or a voltage sensitive device, then you want to use a high-side switch.

Can a p channel be used on a low side transistor?

For a P-Channel MOSFET, the source connects to the voltage source, and the drain connects to the load’s positive side. Like with the low-side, you probably want to use an enhancement mode MOSFET. Keep in mind that you may never find a depletion mode P-Channel.

When to use a high side transistor driver?

Until the FET is saturated, its Rds-ON can be relatively high, limiting the maximum current it can handle. It is very common to use an NPN driver with a PNP BJT or P-Channel MOSFET, when the load voltage is higher than the signal voltage. Without a driver, the transistor may never turn-off.