SLVUAO9C March 2016 – June 2021 TPS56C215
The board layout for the TPS56C215EVM-762 is shown in Figure 3-1 through Figure 3-5. The top-side layer of the EVM is laid out in a manner typical of a user application. The top, bottom, and internal layers are
2-oz. copper.
The top layer contains the main power traces for VIN, VOUT, and SW. Also on the top layer are connections for the remaining pins of the TPS56C215 and the majority of the signal traces. There is a large area filled with ground. The internal layer-1 is dedicated ground plane with an island for quiet analog ground that is connected to the main power ground plane at a single point. The internal layer-2 contains an additional large ground copper area as well as an additional VIN and VOUT copper fill. The bottom layer is another ground plane with two additional traces for the output voltage feedback and BST capacitor connection. The top-side ground traces are connected to the bottom and internal ground planes with multiple vias placed around the board.
The input decoupling capacitors and bootstrap capacitor are all located as close to the IC as possible. Additionally, the voltage setpoint resistor divider components are kept close to the IC. The voltage divider network ties to the output voltage at the point of regulation, the copper VOUT trace at the TP9 test point. For the TPS56C215, an additional input bulk capacitor may be required, depending on the EVM connection to the input supply. Critical analog circuits such as the voltage set point divider, EN resistor, SS capacitor, MODE resistor, and AGND pin are terminated to quiet analog ground island on the internal layer-1.