Diode - Basic Applications

1. Diode – Basic
Applications
Yong Heui Cho @ Mokwon University
Some of slides are referred to:
[1] A. S. Sedra & K. C. Smith, Microelectronic Circuits.

2. 2
Electronic Circuits
4. Diode – Operational Principle
5. Diode – V/I
6. Diode – Basic Applications
7. Diode – Advanced Applications

3. 3
Half-wave Rectifier
• Rectifier converts an AC into a DC by allowing a
current to flow through it in one direction only.
vO = 0, vS < VD0
R
R + rD
vS - VD0
R
R + rD
vO
=
vS ≥ VD0
≈ vS – VD0 , for rD ≪ R

4. 4
Full-wave Rectifier
PIV = 2VS – VD0

5. 5
Bridge Rectifier
vD3(reverse) = vO + vD2(forward)
PIV = Vs -2VD + VD = Vs - VD

6. 6
Voltage Regulator
• VR automatically maintains a constant
voltage level
– Zener diode or IC

7. 7
Ideal Peak Detector
Ideal case

8. 8
Real Peak Detector
t1 < t < t2
Vr = VP – vO(T-ΔT) =
iDmax = IL(1 + 2π√2Vp/Vr)iDav = IL(1 + π√2Vp/Vr)

9. 9
DC Power Supply
V1 / V2 = N1 / N2
transformer

10. 10
Simple Power Supply
• No transformer
• Bridge rectifier, Zener diode, voltage divider
with C, peak detector

11. 11
IC-based Power Supply
• Transformer, bridge rectifier, peak detector,
regulator IC