Sites:

## Understanding the AC, DC and Peak Currents

We have seen that the ac component (I AC = ?I/2) is derivable from the voltseconds law. From the basic inductor equation V = LdI/dt, we get

So the current swing I PP ? ?I, can be intuitively visualized as " voltseconds per unit inductance". If the applied voltseconds doubles, so does the current swing (and ac component). And if the inductance doubles, the swing (and ac component) is halved.

Let us now consider the dc level again. Note that any capacitor has zero average (dc) current through it in steady-state, so all capacitors can be considered to be missing altogether when calculating dc current distributions. Therefore, for a buck, since energy flows into the output during both the on-time and off-time, and via the inductor, therefore the average inductor current must always be equal to the load current. So

On the other hand, in both the boost and the buck-boost, energy flows into the output only during the off-time, and via the diode. Therefore, in this case, the average diode current must be equal to the load current. Note that the diode current has an average value equal to I L when it is conducting (see the dashed line passing through the center of the down-ramp in the upper half of Figure 2-3). If we calculate the average of this diode current over the entire switching cycle, we need...

##### Products & Services
Switching Power Supplies
Switching power supplies are DC sources that use a switching element (normally a power transistor) to generate the desired voltage. Switching power supplies are also called switch-mode products or switching mode power supplies (SMPS).
Ferrite beads are used to suppress unwanted signals that can interfere with electrical devices such as DC supplies, transmission lines and cables. They provide attenuation of selected frequency bands.
DC-DC Converter Chips
DC-DC converter chips provide a regulated DC voltage output from a different, unregulated input voltage.&nbsp;
Rectifiers
Rectifier diodes are designed for use in rectification circuits. Rectifiers are used to convert AC to DC.
Inductance standards and decades provide highly accurate and digitally variable standard values of inductance for calibration, comparison and testing.

##### Topics of Interest

Defining the "Worst-Case" Input Voltage So far, we have been implicitly assuming a fixed input voltage. In reality, in most practical applications, the input voltage is a certain range, say from 'V...

3.4 Understanding the AC, DC and Peak Currents We have seen that the AC component (I AC = ?I /2) is derivable from the voltseconds law. From the basic inductor equation V =L dI/dt, we get So the...

The DC Level and the "Swing" of the Inductor Current Waveform From V = LdI/dt, we get ?I = V ?t/L. So the " swinging" component of the inductor current " ?I" is completely determined by the applied...

3.2 The DC Level and the "Swing" of the Inductor Current Waveform From V = L dI/dt we get ? I = V ?t/L. So the "swinging" component of the inductor current "? I" is completely determined by the...

How Inductance and Inductor Size Depend on Frequency The following discussion applies to all the topologies. If keeping everything else fixed (including D) we double the frequency, the voltseconds...

Product Announcements