What Is a High-Side Driver?
A high-side driver is a circuit configuration used on electronic circuits to drive a switch element between a power supply and a load.
The switch element to be driven is called a high-side switch, and the high-side switch is controlled to turn the power supply on and off and to supply or disconnect current to the load. In contrast, a driver that drives the switch element placed between the load and ground is called a low-side driver.
To supply current to various loads, high-side drivers and low-side drivers have unique characteristics in their respective circuits.
Uses of High-Side Drivers
High-side drivers are widely used in electronic circuits. Typically, they are used in inverters, power on/off circuits, LED drive drivers, and to drive inductance loads such as motors and solenoids.
High-side drivers are often used to supply large currents to loads, and must be designed with inrush current countermeasures and reverse current prevention circuits in mind. Since a switch element is inserted between the load and the power supply, it is possible to design the driver with consideration for operation in the event of a ground short circuit or other failure.
Types of High-Side Drivers
High Side Drivers
High-side drivers monitor the current flowing through the switch because the switch element to be driven is placed between the power supply and the load. A ground short can be detected, and the overcurrent caused by the short can be stopped by turning off the switch.
Low-Side Drivers
Low-side drivers can easily use N-channel MOSFETs because the voltage between the gate and source is ground referenced. Even if the voltage applied to the load is high, the voltage on the driver side does not depend on the voltage on the load side, and a low supply voltage is sufficient. The selection of elements can be aggressive even with low withstand voltage elements, and the configuration can be advantageous in terms of size and cost.
The disadvantage of high-side drivers and low-side drivers is that they cannot match the advantages of each other. High-side driver configurations are often larger and more expensive than low-side drivers. Low-side drivers are not as protected against short circuits, which is possible with high-side drivers.