Part # Application Notes Mobile STLD40D AN2333 datasheet

Part Manufacturer: ST Microelectronics

ST Microelectronics

Part Description: White LED power supply for large display backlight


Part Details:

AN2333 Application Note White LED power supply for large display backlight Introduction This application note is dedicated to the STLD40D, it s a boost converter that operates from 3.0V to 5.5Vdc and can provide an output voltage as high as 37Vdc and can drive up to 10 white leds in series. Package Pin configuration May 2006 Rev 2 1/11 www.st.com Contents AN2333 Contents 1 Schematic description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1 Application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Selection of external components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1 Input and output capacitor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 LED selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 PCB design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 PCB design rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2/11 AN2333 List of figures List of figures Figure 1. Typical application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 2. ILED vs RLED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 3. ILIMT-ADJ vs RSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 4. vs VI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 5. ILED vs Duty cycle EN pin (Dimming) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 6. PCB layout - Top overlay view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3/11 Document Outline


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Application Notes Mobile STLD40D AN2333.pdf Datasheet