11.1 Layout Guidelines

The PCB layout is an important step to maintain the high performance of the TPS6208x devices.

The input/output capacitors and the inductor should be placed as close as possible to the IC. This keeps the traces short. Routing these traces direct and wide results in low trace resistance and low parasitic inductance. A common power GND should be used. The low-side of the input and output capacitors must be connected properly to the power GND to avoid a GND potential shift.

The sense traces connected to the FB and VOS pins are signal traces. Special care should be taken to avoid noise being induced. By a direct routing, parasitic inductance can be kept small. GND layers might be used for shielding. Keep these traces away from SW nodes.

11.2 Layout Example

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Figure 31. PCB Layout Suggestion

11.3 Thermal Considerations

Implementation of integrated circuits in low-profile and fine-pitch surface-mount packages typically requires special attention to power dissipation. Many system-dependent issues such as thermal coupling, airflow, added heat sinks and convection surfaces, and the presence of other heat-generating components affect the power-dissipation limits of a given component.

Three basic approaches for enhancing thermal performance are listed below:

• Improving the power dissipation capability of the PCB design
• Improving the thermal coupling of the component to the PCB by soldering Exposed Thermal Pad
• Introducing airflow in the system

For more details on how to use the thermal parameters, see the application notes: Thermal Characteristics of Linear and Logic Packages Using JEDEC PCB Designs (SZZA017) and Semiconductor and IC Package Thermal Metrics (SPRA953).