How do you know which inductor to use?
An inductor should have a high value of rated current so that it can operate in linear range over the entire load. Also, it should have low DC resistance to minimize losses and increase the efficiency of the regulator. It should also have a small size which is important for printed circuit boards (PCBs).
How do you select the value of an inductor?
To get a good compromise between inductor and capacitor size, you should choose a ripple current value of 10% to 30% of maximum load current. This also implies that the current in the inductor will be continuous for output currents greater that 5% to 15% of full load.
What is a normal inductance value?
Inductors have values that typically range from 1 µH (10−6 H) to 20 H. Many inductors have a magnetic core made of iron or ferrite inside the coil, which serves to increase the magnetic field and thus the inductance.
How do you select the inductor value of a buck converter?
When selecting an inductor for a buck converter the following parameters need to be defined:
- Maximum input voltage = Vin max.
- Minimum input voltage = Vin min.
- Maximum output current = Iout max.
- Operating frequency = f.
- Output voltage = Vout.
- Minimum output current = Iout min.
What should be considered when choosing an inductor?
Most inductor manufacturers recognize this division and have tailored their datasheets to provide an engineer with the electrical parameters required to design their part into an RF or power circuit. For RF electronics, the main factors considered are the component’s quality (Q) factor and its self-resonant frequency (SRF).
What should be the peak current of an inductor?
To allow some margin, you should select a value of 10µH. This gives a nominal peak-to-peak ripple current of 450mA. In the finished design, this can be seen as an output ripple voltage of 0.45 × output capacitor ESR. Inductors are normally specified with two current ratings: continuous (Irms) and peak (Isat).
How to choose the correct inductor for a buck converter?
For a buck converter, choosing the correct value of inductance is important to obtain acceptable inductor and output capacitor sizes and sufficiently low output voltage ripple. As you can see from Fig. 1, the inductor current is made up of ac and dc components.
What do you need to know about RF inductors?
Apart froth inductance of the inductor, there are some other key parameters that need to be considered when selecting and buying an inductor for RF applications. One of these is the Q of the inductor. The Q factor essential describes the ratio of the reactance of the inductor to its resistance.