LED driver is the power source for LED lights, which is used to provide and properly deliver the required output. LED drivers can be divided into two categories: Constant Current and Constant Voltage Driver. Both types are AC/DC converting, which means it converts AC voltage from main power supply (100-240V) to DC supply which is suitable for LED lights. But the delivery methods are different, so what’s the difference between constant current and constant voltage drivers?

Constant Current LED Driver

Constant current LED drivers are designed with a fixed current output but variable voltage output. The voltage output will be changed depending on the number of LED used, but ensure that the actual voltage output is within the rated voltage range.

Constant current LED driver is commonly used, as it can avoid the output current exceeding the maximum rating, while ensure the LED meets the expected brightness requirements and each LED brightness is consistent, which cannot be achieved by constant voltage driver.

Constant Current Example
Input Voltage Output Voltage Output Current (Amps)
100-240VAC 4-10VDC 700mA*
Note* The current is set to only one designated value.

Constant Voltage LED Driver

Similarly, constant voltage LED driver will have a fixed voltage output, depending on the rated voltage of LED. The output voltage is fixed, while the current output will have a maximum rating. If the actual current demand of the circuit does not exceed its rated current range, it can work normally. Constant voltage drivers are usually used in applications where all LED are in series.

Constant Voltage Example
Input Voltage Output Voltage Output Current (Amps)
120-240VAC 24VDC** 1 Amp Max
Note** The voltage is set to only one designated value.

Before choosing LED driver, it’s very important to understand the operational parameters of the LED first. Otherwise, LED can be damaged by too high a current or too high a voltage. It is necessary to abide by one basic principle that, the output current and output voltage of the power supply must meet the input voltage and input current operating range of the chip. If this range is exceeded, the life of the chip will be affected.