9.1 Layout Guidelines

For best overall performance, place all circuit components on the same side of the circuit board and as near to the respective LDO pin connections as possible. Place ground return connections to the input and output capacitor, and to the LDO ground pin as close to each other as possible, connected by a wide, component-side, copper surface. The use of vias and long traces to create LDO component connections is strongly discouraged and negatively affects system performance. This grounding and layout scheme minimizes inductive parasitics, and as a result, reduces load-current transients, minimizes noise, and increases circuit stability. TI recommends using a ground reference plane, and is embedded in the printed circuit board (PCB) itself or located on the bottom side of the PCB opposite the components. This reference plane ensures accuracy of the output voltage, shields the LDO from noise, and operates similar to a thermal plane to spread (or sink) heat from the LDO device when connected to the exposed thermal pad. In most applications, this ground plane is required to meet thermal requirements.