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The design uses a LM2743 synchronous controller utilizing external high side and low side N-channel MOSFETs operating at frequency from 100khz - 500kHz nominal based upon the frequency set resistor value (R8). Careful PC board layout is critical to achieve low switching losses and clean, stable operation. The switching power stage requires particular attention. Few points to note for this design are:
1) Decoupling capacitors are close to IC pins as possible. Keep separate power ground plane.
2) Input and output capacitors are connected to the power ground plane; all other capacitors are connected to the signal ground plane.
3) High current paths are very short.
4) Multiple MOSFETs have been used to reduce the conduction and switching losses.
5) Feedback connections are short and direct and routed away from any noisy traces (i.e. switch node).
6) High-side MOSFETs are as close as possible to the controller
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Example Schematic Showing Connection for all Components.
