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.
Layout Example provides an example of layout design with the TPS61085A-Q1 device.
- Use wide and short traces for the main current path and for the power ground tracks.
- The input capacitor, output capacitor, and the inductor must be placed as close as possible to the IC.
- Use a common ground node for power ground and a different one for control ground to minimize the effects of ground noise. Connect these ground nodes at the GND terminal of the IC.
- The most critical current path for all boost converters is from the switching FET, through the rectifier diode, then the output capacitors, and back to ground of the switching FET. Therefore, the output capacitors and their traces must be placed on the same board layer as the IC and as close as possible between the SW pin and the GND terminal of the IC.