1. Load-Line Analysis of Complex Circuits with small signal diode model
* Use the Thevenin Equivalent

2. Question
Find the power dissipated by the diode assuming that we use small signal diode model.

3. Cct. Models for semiconductor diodes
Diode Models
Large Signal
Small Signal
Piecewise Linear
Ideal Diode
Offset Diode

4. Piecewise linear Diode Model
For this model we assume the following:
Cutoff frequency >0
Internal resistance
(rD) >0
(but constant!!)
Reverse current =0.
The approximation mainly in the value of the internal resistance.

5. Piecewise-Linear Diode Models
Now, diode voltage is the sum of resistance voltage and cutoff frequency voltage.

7. Other Diode Types (Zener Diode )
Reverse Bias Piecewise Linear Model
Zener symbol
Operates in the reverse mode.
Constant voltage with varying current (at break down voltage)
Can be used as avoltage regulator.
(VBR)

8. Example – Zener-Diode Voltage-Regulator Circuits

9. Example