Constant Current Drivers vs. Constant Voltage Drivers

A Technical Comparison

Constant current drivers (CC drivers) and constant voltage drivers (CV drivers) are two fundamental types of power supply mechanisms used in various electrical and electronic applications. Understanding the differences between these drivers is essential for designing and operating devices efficiently. In this technical write-up, we will delve into the principles, applications, advantages, and disadvantages of constant current and constant voltage drivers.

Constant Current Drivers (CC Drivers)

Constant current drivers, as the name suggests, maintain a steady current output irrespective of the load's resistance. In other words, the current remains constant while the voltage may vary to accommodate changes in load impedance.


LED Lighting: CC drivers are commonly used to power LEDs. LEDs have a specific forward voltage and require a precise current to operate efficiently. CC drivers ensure that the LED operates at its optimal current, preventing overcurrent, which can damage the LED.

Laser Diodes: Laser diodes also require a stable current to maintain their desired output characteristics. CC drivers are employed to provide this stable current.

Advantages of CC Drivers:

- Precise control of current, ensuring consistent device performance.

- Ideal for devices with specific current requirements.

- Improved efficiency for devices with varying resistance.

Disadvantages of CC Drivers:

- Inflexible for devices that require a constant voltage.

- Voltage may drop as the load increases, affecting the brightness or performance of some components.

Constant Voltage Drivers (CV Drivers)

Constant voltage drivers maintain a stable voltage output, regardless of the changes in the load's impedance. The current supplied to the load varies as a result of Ohm's law (V = IR).


Powering Electronics: Most consumer electronics, including laptops, smartphones, and audio equipment, use CV drivers to provide a consistent voltage to their internal components.

Charging Devices: USB chargers and power adapters are CV drivers designed to deliver a constant voltage to charge various devices, including smartphones and laptops.

Electric Motors: Many electric motors, such as those in appliances and industrial machinery, operate on a constant voltage supply.

Advantages of CV Drivers:

Versatile, as they can power a wide range of devices with different current requirements.

Simplify power distribution by maintaining a consistent voltage level.

Disadvantages of CV Drivers:

Unsuitable for devices that require a constant current, like domestic LED downlights and laser diodes.

Load resistance fluctuations can also affect the device's performance.


Constant current drivers and constant voltage drivers serve distinct purposes in electrical and electronic systems. CC drivers are ideal for applications requiring precise current regulation, such as LED lighting and laser diodes. On the other hand, CV drivers are versatile and commonly used to power a wide range of electronics and appliances. Understanding the requirements of your specific application is crucial in choosing between these two types of drivers, as they significantly impact the performance and efficiency of your devices.

Series and Parallel Connections
Connecting Batteries in Series or Parallel. Changing their overall voltage or capacity