驅動發光二極管-模擬和數字拓撲之間的選擇

　　模擬或數字驅動器之間的選擇取決于應用程序的要求。無論您選擇哪條路線，您都只是通過了許多決策點的第一步。

　　LED不再是控制臺或圣誕裝飾品上簡單的指示燈，LED正在完全改變照明行業。效率高，成本低，使用壽命長，繼續取代現有的照明技術。此外，用于LED開發的硅和設計工具使得在所有行業的應用程序中充分利用這些設備成為可能。

　　對這項技術最新的工程師們的挑戰是LED是由相當復雜的模擬系統驅動的。系統可以基于電流或電壓，并且在負載、顏色變化和字符串長度之間保持高級一致性和效率。更復雜的設計是一個事實，即LED從不同的生產運行變化很大，足以要求校準一些應用程序。

　　There are also many approaches for implementing LED technology， varying from very simple analog driver circuitry for light bulb replacement， to advanced digital MCU-based systems for stage or street lighting， requiring adaptive compensation and remote control through a wired or wireless communications link. Which implementation is optimal， however， depends upon many factors. This article will look at some of the more important elements of an LED-based design and their impact on cost， power efficiency， and design simplicity.

　　Analog versus digital

　　A basic LED system takes an AC or DC input and converts it to an appropriate DC voltage or current to drive the LED （see Figure 1）。 One of the most common applications utilizing a pure analog topology is light bulb replacement， where the LED system needs to be as simple as the product it is replacing. For such an application， advanced features such as a communications link or internal intelligence are unnecessary， making an analog approach ideal.