Sinrace Power Supply Technology (Shenzhen) Co., Ltd.

There is no such thing as a universal power LED driver circuit.

In reality, different power LED applications can have very different technical requirements. And there is a wide choice of components available, at a wide range of prices, to meet these requirements.

In other words, the decision over the choice of a driver circuit for a lighting application is complex, and has reference to many variables. To help the design engineer avoid the waste of time and effort involved in evaluating different power topologies through trial and error, this article elaborates a systematic method for choosing the right topology in the light of a clear and simple set of application parameters.

The key considerations that have to be borne in mind in order to reach the right decision are:

* What is the power source (AC mains, low-voltage DC, battery or other)?

* What is the relationship between the input and output voltages?

* What is the range of voltages required in the system?

* What is the power requirement?

* Is isolation required?

* Is dimming required?

* Does the supply have to power multiple channels (for instance in RGB colour-mixing applications)?

* What are the EMC constraints?

* What is the bill of materials budget?

A decision tree leading from the particular conditions of a circuit to a topology and component type that best meets the demands of the application provides a valuable first level of discrimination between the various methods for powering LEDs . The design engineer will still have choices, between topologies (in some cases) and between components (in all cases). Then, secondary features, such as an IC’s ability to provide pulse width modulation (PWM) control, can make one device preferable to another.
But it is essential to productive design that the first high-level choice – that of topology – is right.