Calculation of buck energy storage inductance

What is a good inductor size for a buck converter?

The inductor value can be increased to reduce the ripple-ratio; however, this will typically result in an inductor size that is physically too big for practical use. Consequently, “r” is usually set between 0.2 and 0.5 for buck converters. or Current flowing through the coil is a combination of output current and ripple-current.

What is a high inductance Buck regulator?

A high inductance reduces ΔI and results in lower ‘r' (and lower RMS current in the output capacitor), but may result in a very large and impractical inductor. So typically, for most buck regulators, ‘r' is chosen to be in the range of 0.25–0.5 (at the maximum rated load). See Appendix A.

What is buck converter power stage?

Buck Converter Power Stage Integrated circuit used to build the buck converter. This is necessary because some parameters for the calculations must be derived from the data sheet. If these parameters are known, the power stage can be calculated.

Does a buck converter have a diode?

Some converters have the diode replaced by a second switch integrated into the converter (synchronous converters). If this is the case, all equations in this document apply besides the power dissipation equation of the diode. Figure 1. Buck Converter Power Stage Integrated circuit used to build the buck converter.

How does the size of an inductor affect the energy requirement?

The size of the inductor is related to the energy handling capability required. The energy handling capability is 1⁄2*L*IPEAK 2. For a given application, if we reduce inductance, it seems that this would increase ΔI and thereby IPEAK, which would cause the energy requirement to increase since it depends on square of current.

What is a buck converter circuit?

A buck converter is a specific type of switching regulator that steps down the input voltage to a lower level output. Fig. 1 shows a typical buck converter circuit when switching element Q1 is ON. When N-ch MOSFET Q1 is ON, current flowing from input VIN to coil L charges the output capacitor CO and supplies output current IO.