JAJSPD7 December 2022 LMR51440 , LMR51450
PRODUCTION DATA
The LMR514x0 is a step-down DC-to-DC converter. The device is typically used to convert a higher input voltage to a lower output DC voltage with a maximum output current of 4 A or 5 A. The following design procedure can be used to select components for the LMR514x0 . Alternately, the WEBENCH® software can be used to generate complete designs. When generating a design, the WEBENCH® software uses iterative design procedure and accesses comprehensive databases of components. Go to ti.com for more details.
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 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 ensure that the minimum value of effective capacitance is provided.