10.1 Layout Guidelines

The LM25011 regulation and current limit comparators are very fast, and respond to short-duration noise pulses. Layout considerations are therefore critical for optimum performance. The layout must be as neat and compact as possible, and all of the components must be as close as possible to their associated pins. The two major current loops conduct currents which switch very fast, and therefore those loops must be as small as possible to minimize conducted and radiated EMI. The first loop is formed by C_IN, through the VIN to SW pins, L_IND, C_OUT, and back to C_IN. The second current loop is formed by R_S, D1, L_IND, C_OUT, and back to R_S. The ground connection from CSG to the ground end of C_IN should be as short and direct as possible.