Transcript Diodes Benchmark Companies Inc PO Box 473768 Aurora CO 80047 Diodes Objective 1 Diodes 1. Identify the purpose of a diode 2.

Diodes
Benchmark Companies Inc
PO Box 473768
Aurora CO 80047
Diodes
Objective 1
Diodes
1. Identify the purpose of a diode
2. Identify different types of diodes
3. Recognize diode schematic symbols and reference
symbols.
Diode Construction
1. Describe semiconductor material
2. Identify N-type and P-type semi-conductor material
3. Describe forward and reverse biasing
Back
Diodes
Diodes are a critical part of electronics. In this section we will
discover just how important they really are……...
Junction Diode
Zener Diode
Light Emitting Diode
The symbol and notation of different types of diodes
Back
Diodes
Diodes come in several sizes and shapes. A typical identification
method is as follows….
Diode
Solid State Device
Type of Diode
1N914
A typical silicon diode with identifier
Back
Diodes
Diodes allow current to flow in one direction, while preventing
current to flow in the other direction.
Electron Flow
Back
Diodes
Diodes allow current to flow in one direction, while preventing
current to flow in the other direction.
Reverse Bias
(no current)
Back
Diodes
P
N
ANODE
Diode symbols are illustrated above. The Positively doped
material is represented by an arrow and is called the ANODE.
Back
Diodes
P
N
Cathode
Diode symbols are illustrated above. The Negatively doped
material is represented by a bar and is called the CATHODE.
Back
Diodes
Electron Flow (Forward Bias)
Conventional Flow of current
It is important to understand the electron flow versus
conventional flow of current.
Back
Diodes
Biasing the Silicon Diode
+
-
When in forward bias mode, the diode is a short
Back
Diodes
Biasing the Silicon Diode
+
-
When in a reverse bias mode, the diode acts as an open.
Back
Diodes
Barrier Junction
P
N
Configuration of a forward bias diode
Electrons are attracted into the N-type material
and attract to the holes.
Back
Diodes
Barrier Junction
P
N
Configuration of a Reversed bias diode
As the diode is reversed biased, the attraction
Of P-type and N-type is towards the outer edges.
Back
Diodes
Voltage Drops in the Silicon Diode
FORWARD BIAS
Electron Flow
.7 volt drop
When in forward bias mode, the silicon diode has
approximately a .7 volt drop across the junction
Back
Diodes
Voltage Drops in the Silicon Diode
REVERSE BIAS
When in a reverse bias mode, the silicon diode acts
as an open.
Back
Diodes
Current
Controlled Current
Limit
Reverse
Bias
Forward
Bias
Volts
Leakage current
.7V Knee voltage
Reverse Breakdown
(Avalanche)
Characteristic Curve of a Junction Diode
Current vs Voltage
Back
Diodes
Summary on Diodes
•Three types of Diodes were discussed
•Junction diode
•Zener diode
•Light emitting diode
Back
Diodes
Summary on Diodes
•Junction diodes contain:
•Anode (Ptype material)
•Cathode (Ntype Material)
Back
Diodes
Summary on Diodes
•Forward bias
•Diodes simulate a short
•Reverse bias
•Diodes simulate an open
Back