Practical Model

In practice we find that there is a voltage drop of about 0.7 V across the diode (silicon; germanium is 0.3 V) when it is forward biased, and so it is often useful to include this voltage drop in circuit analysis. Accordingly, the practical model is the ideal model with the addition of a voltage source in the forward bias model. Figure 75 shows the practical model characteristic. The practical model is shown in Figure 76.

**Figure 75:** Practical diode characteristic.
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**Figure 76:** Practical diode model.
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