JAJSFE5C October 2009 – May 2018 TPS65720 , TPS65721
PRODUCTION DATA.
As for all switching power supplies, the layout is an important step in the design. Proper function of the device demands careful attention to PCB layout. Care must be taken in board layout to get the specified performance. If the layout is not carefully done, the regulators may show poor line or load regulation, and additional stability issues as well as EMI problems. Providing a low impedance ground path is critical. Therefore, use wide and short traces for the main current paths. The input capacitors must be placed as close as possible to the IC pins as well as the inductor and output capacitor.
For TPS65721, connect the PGND pin of the device to the thermal pad land of the PCB and connect the analog ground connection (GND) to the PGND at the thermal pad. Keep the common path to the GND pin, which returns the small signal components, and the high current of the output capacitors as short as possible to avoid ground noise. The FB line should be connected right to the output capacitor and routed away from noisy components and traces (for example, the L1 line). See the TPS65720EVM User's Guide for details about the layout.