SNVSCM6 February 2024 LMR38015
PRODUCTION DATA
The LMR38015 step-down DC-to-DC converter is typically used to convert a higher DC voltage to a lower DC voltage with a maximum output current of 1.5A. The following design procedure can be used to select components for the LMR38015. Alternately, use the WEBENCH Design Tool to generate a complete design. This tool uses an iterative design procedure and has access to a comprehensive database of components. This feature allows the tool to create an optimized design and allows the user to experiment with various options.
All of the capacitance values given in the following application information refer to effective values unless otherwise stated. The effective value is defined as the actual capacitance under DC bias and temperature, not the rated or nameplate values. Use high-quality, low-ESR, ceramic capacitors with an X7R or better dielectric throughout. All high value ceramic capacitors have a large voltage coefficient in addition to normal tolerances and temperature effects. Under DC bias, the capacitance drops considerably. Large case sizes and higher voltage ratings are better in this regard. To help mitigate these effects, multiple capacitors can be used in parallel to bring the minimum effective capacitance up to the required value. This action can also ease the RMS current requirements on a single capacitor. A careful study of bias and temperature variation of any capacitor bank must be made to make sure that the minimum value of effective capacitance is provided.