Constant Current and Constant Voltage – What’s the difference?

Constant current (CC) and constant voltage (CV) are common are two common terms that distinguish between the two available types of LED drivers used in electronics, particularly in LED lighting. The main difference between the two lies in how they regulate and deliver electrical power to the connected load. This difference is paramount. The LED application will determine what type of driver is needed, as it will depend on the specific requirements of the electronic device or lighting system being powered.

Constant current (CC) drivers are suited to applications where the load requires a fixed current. They use a variable voltage in order to maintain a constant electrical current output. This works by the driver ensuring that the current flowing through the load remains steady, even if the load’s resistance changes. In this way, CC LED drivers typically offer better control and a more efficient circuit, in comparison to constant voltage drivers.

Constant current LED drivers are a popular choice for LED applications and are suitable for use with LED chains or single LEDs operating in series. They are commonly used in applications where the load requires a consistent current for optimal performance and longevity.

Whereas constant voltage (CV) drivers supply a fixed set voltage output to the electronic circuit. The current drawn by the load varies based on its resistance. Constant voltage drivers are useful when a steady voltage level is essential, as they allow the current to vary based on the load’s requirements.

Devices that require a fixed voltage input, such as some electronic gadgets and components, use constant voltage drivers to maintain a consistent voltage level across the load. So constant voltage LED drivers are ideal for a parallel circuit made up of multiple LEDs. They are best suited for LED modules with either an on-board or a current limiting resistor, such as an LED strip.