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White LED Step-Up Converter
PT6937
BOARD LAYOUT CONSIDERATION
As with all switching regulators, careful attention must be paid to the PCB board layout and component
placement. To maximize efficiency, switch rise and fall times are made as short as possible. To prevent
electromagnetic interference (EMI) problems, proper layout of the high frequency switching path is
essential. The voltage signal of the SW pin has sharp rise and fall edges. Minimize the length and area
of all traces connected to the SW pin and always use a ground plane under the switching regulator to
minimize inter-plane coupling. In addition, the ground connection for the feedback resistor R1 should
be tied directly to the GND pin and not shared with any other component, ensuring a clean, noise-free
connection. Recommended component placement is shown in Figure 5
(SOT-23 Package)
Figure 5. Recommended Component Placements
PT6937 V1.1
-7-
March, 2006
PTC [ PRINCETON TECHNOLOGY CORP ]
