P Channel Mosfet High Side Switch

Because of how transistors work these can be a little more difficult to use in an arduino or raspberry pi circuit.

P channel mosfet high side switch. In this configuration when the high side switch is realized with a p channel mosfet the driver design will be simplified enormously. No charge pump is required for driving the high side switch. To switch v with a p channel mosfet use a p channel mosfet with source connected to v either directly or via a current limiting resistor and the load connected to drain. Typically these use a pnp bjt or p channel mosfet.

The opposite of the low side switch is the high side switch. Usually the source pin must be more positive than the drain however this isn t true when using a p mosfet to provide reverse polarity protection for instance. However this cure can also have some side effects. P channel mosfets generally have a higher r dson compared to n type mosfets having a similar internal chip size.

Then the p channel mosfet is used to switch the positive supply to the motor for forward direction high side switching while the n channel mosfet is used to switch the negative supply to the motor for reverse direction low side switching. It s a simple circuit that has a input for positive and negative and an output for positive and negative connections. The current necessary for the relay coil is too high for an i o pin but the coil needs 5v to work. If your load voltage is higher like 12 or 24v then you might want to use an n channel mosfet in a low side configuration.

P channel mosfet high side switch here s my schematic and board design for a simple high side switch using a p channel mosfet. There are a variety of configurations for driving the two mosfets with many different applications. The p channel high side switch therefore solves the problem of using an n channel mosfet for high side switching. This transistor connects between v and the load.