How to select LED drive mode for LED lighting design

Linear regulator structure is relatively simple, easy to design, to provide constant current and over-current protection, and no electromagnetic compatibility (EMC) problem. In the low current LED application, although the driver resistance type is of low cost and simple structure, but the driver under the condition of low voltage, low current, LED will lead to insufficient brightness, and the load dump transient conditions, LED may be damaged; and resistance is energy dissipation components, the whole scheme of energy efficiency is low.

Today, the typical LED drives in the market include two categories, namely linear drives and switch drivers.

As the current application current is greater than 500mA by switching regulator, because linear actuators limited to their structure, unable to provide such a large current; while in the low current application current is less than 200mA, usually using a linear regulator or separation regulator; and in the middle of 200 to 500mA in the current application, not only can use a linear regulator, also can be used for switching regulator.

The switching regulator has high energy efficiency and provides excellent brightness control. Linear regulator structure is relatively simple, easy to design, to provide constant current and over-current protection, and no electromagnetic compatibility (EMC) problem.

In the low current LED application, although the driver resistance type is of low cost and simple structure, but the driver under the condition of low voltage, low current, LED will lead to insufficient brightness, and the load dump transient conditions, LED may be damaged; and resistance is energy dissipation components, the whole scheme of energy efficiency is low. See below.