The D5026A is a driver IC designed by Shanghai Becker Electronics for energy-saving LED displays . Its design concept is energy-saving and compatible with existing solutions, which means it can be used for energy saving or compatibility with tradition. After calculation and testing, the display made with D5026A can save up to 30%. Here is a brief introduction to the energy saving principle of the D5026A.
Figure 1 Traditional 5026 drive output structure
Figure 2 5026 constant current schematic of each unit
As we all know, the LED driver usually adopts the constant current source driving mode. Figure 1 is the traditional 5026 driving output structure, and Figure 2 is the constant current principle of each unit. Its constant current output current Io = Vr / Rf. In this output mode, the output voltage Vo is composed of a voltage drop Vr across Rf and a voltage drop Vds1 on the output transistor A1, that is, V.=Vr+Vds1. In the constant current state, Vds1 changes with load. When the output current is constant, we always have a point to make Io exit the constant current state when we reduce Vo. At this point we call it the lowest output voltage Vomin. We can combine Io=Vr/Rf with V.=Vr+Vds1. It is easy to see that the output will not be constant when V.-Vds1 is lower than Vr. At this time, Vds1 is about 0.1V, and the lowest output voltage is Vomin=Vr+0.1(V).
Figure 3 D5026A drive output structure diagram
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