AN2654

Board description

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Figure 4.

PCB bottom-side view

1.2

Schematic

This CCFL backlighting solution is designed for 17" LCD monitors. This development design

board is able to drive 4 tubes of CCFL. During normal conditions, the L6574 provides a

current loop that is controlled by varying the switching frequency. The input DC bus voltage

has been lifted to 110 V. This reference design provides an open lamp protection,

overvoltage protection, soft-start time setting, and analog and digital dimming functions.

Figure 5 shows the application schematic and Table 2 gives the bill of materials.