11.7 : 二极管反向特性建模

Modeling the reverse characteristics of a diode involves examining a reverse-biased diode circuit.

Consider a Zener diode circuit possessing a breakdown voltage that matches the desired output voltage.

The diode enters the breakdown region when the reverse voltage surpasses the breakdown voltage.

The current-voltage characteristic curve closely approximates a straight vertical line for currents exceeding the knee current.

Kirchhoff's voltage law can be employed to deduce a mathematical expression that establishes the relationship between the diode current, the source voltage, and the diode voltage drop.

This relationship is graphically represented as a straight line, referred to as the load line.

The point at which the load line intersects with the diode curve, denoted as point Q, signifies the operating point of the circuit.

In the datasheet of the Zener diode, the manufacturer provides the breakdown voltage, knee current, increment resistance, and power rating.

The power rating of the Zener diode helps to calculate the maximum possible current through the Zener diode without damaging it.