Zener Diode Circuits for Power Supply Designs

Section 4.4

In this lecture, we will:

Apply the characteristics of the Zener diode to a Zener diode voltage regulator circuit.

Block Diagram for an AC to DC Converter

(Power Supply)

Voltage Regulator

The characteristics of the Zener diode determines VL.

LIZ

i

ZPSI

L

ZL

IIIRVV

I

RVI

Example Problem I

Example Problem I

Example Problem I

Example Problem II

Example Problem II

Example Problem II

Example Problem II

Load Line Analysis

The reverse bias I-V is important for Zener diodes.

The Zener diode begins to conduct when VPS = VZ. When VPS ≥ VZ: VL = VZ

IL = VZ/RL,, but VZ ≠ constant

I1 = (VPS – VZ)/Ri

IZ = I1 - IL

Voltage Rectifier with nonzero Zener resistance

Example Problem III

Example Problem III

Example Problem III

Example Problem III

Example Problem III

Example Problem III

Example Problem IV

Example Problem IV

Example Problem IV

Example Problem IV

Example Problem IV