10.1 Layout Guidelines

A recommended PCB layout for the TPS62480 dual phase solution is shown below. It ensures best electrical and optimized thermal performance considering the following important topics:

- The input capacitors must be placed as close as possible to the appropriate pins of the device. This provides low resistive and inductive paths for the high di/dt input current. The input capacitance is split, as is the V_IN connection, to avoid interference between the input lines.

- The SW node connection from the IC to the inductor conducts high currents. It should be kept short and can be designed in parallel with an internal or bottom layer plane, to provide low resistance and enhanced thermal behavior.

- The V_OUT regulation loop is closed with C_OUT and its ground connection. To avoid PGND noise crosstalk, PGND is kept split for the regulation loop. If a ground layer or plane is used, a direct connection by vias, as shown, is recommended. Otherwise the connection of C_OUT to GND must be short for good load regulation.

- The use of thermal (filled) vias underneath the device is recommended for improved thermal performance.

- The FB node is sensitive to dv/dt signals. Therefore the resistive divider should be placed close to the FB (and RS pin in case of using R₃) pin, avoiding long trace distance.

For more detailed information about the actual 4 layer EVM solution, see SLVUAI6.

10.2 Layout Example

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Figure 46. TPS62480 Board Layout