10.1 Layout Guidelines

For all switching power supplies, the layout is an important step in the design, especially at high peak currents and high switching frequencies. If the layout is not carefully done, the regulator could show stability problems as well as EMI problems. Therefore, use wide and short traces for the main current paths, and for the power-ground tracks. The input, output and CP capacitors should be placed as close as possible to the IC. Because C_VAUX carries the peak currents of the gate control block, it should have a compact and direct routing to the VAUX and GND pin 10, staying away from sensitive signals. The CAP, FB, and VREF pins should all be routed close to the IC in order to keep them away from external noise. The total resistance of the voltage divider R₁ + R₂ must be kept in the range as defined in the Recommended Operating Conditions.

The pinout of the device has been defined such that the external components can be placed directly at the pins to allow for a simplified external layout and good performance. Thermal and electrical vias should be used under the exposed thermal pad to the GND plane.