P-N Junction Diode
CONTENTS
CONTENTS
+ 0 ) 2 6 - 4
Learning Objectives
➣ P-N Junction Diode
➣ Derivation of Junction
Resistance
➣ Junction Breakdown
➣ Junction Capacitance
➣ Equivalent Circuit of P-N
Junction
➣ Diode Fabrication
#
P-N JUNCTION
DIODE
➣ Grown Junction
➣ Alloy Junction
➣ Diffused Junction
➣ Epitaxial Junction
➣ Point Contact Junction
➣ The Ideal Diode
➣ The Real Diode
➣ Diode Circuits with D.C. and A.C. Voltage Sources
➣ Diode Clipper and
Clamper Circuits
➣ Clippers
➣ Some Clipping Circuits
➣ Clampers
➣ Summary of Clamping
Circuits
Ç
CONTENTS
CONTENTS
Chemist, led the research for the molecular diode (In the semiconductor industry, called p-n junctions)
2060
Electrical Technology
52.1. P-N Junction Diode
(a) Construction
It is a two-terminal device consisting of a P-N junction formed either in Ge or Si crystal. Its circuit symbol is shown in Fig. 52.1 (a). The P-and N-type regions are referred to as anode and cathode respectively. In Fig. 52.1 (b), arrowhead indicates the conventional direction of current flow when forward-biased. It is the same direction in which hole flow takes place.
Commercially available diodes usually have some means to indicate which lead is P and which lead is N.
Standard notation consists of type numbers preceded by
‘IN’ such as IN 240 and IN 1250. Here, 240 and 1250 correspond to colour bands. Fig. 52.2 (a) shows typical diodes having a variety of physical structures whereas Fig.
52.2 (b) illustrates terminal identifications. Also refer to the picture of two commercial diodes shown in Fig 52.1(c).
(a)
P
N
(b)
Cathode
Anode
a
(c)
k
a
k
a
k
Fig. 52.1
Fig. 52.2
The low-current diodes whose body is about 3 mm long can carry a forward current of about
100 mA, have saturation current of 5 µA at room temperature (25ºC) and can withstand a reverse voltage of 75 V without breaking down. The medium-current diodes can pass a
CONTENTS
+ 0 ) 2 6 - 4
Learning Objectives
➣ P-N Junction Diode
➣ Derivation of Junction
Resistance
➣ Junction Breakdown
➣ Junction Capacitance
➣ Equivalent Circuit of P-N
Junction
➣ Diode Fabrication
#
P-N JUNCTION
DIODE
➣ Grown Junction
➣ Alloy Junction
➣ Diffused Junction
➣ Epitaxial Junction
➣ Point Contact Junction
➣ The Ideal Diode
➣ The Real Diode
➣ Diode Circuits with D.C. and A.C. Voltage Sources
➣ Diode Clipper and
Clamper Circuits
➣ Clippers
➣ Some Clipping Circuits
➣ Clampers
➣ Summary of Clamping
Circuits
Ç
CONTENTS
CONTENTS
Chemist, led the research for the molecular diode (In the semiconductor industry, called p-n junctions)
2060
Electrical Technology
52.1. P-N Junction Diode
(a) Construction
It is a two-terminal device consisting of a P-N junction formed either in Ge or Si crystal. Its circuit symbol is shown in Fig. 52.1 (a). The P-and N-type regions are referred to as anode and cathode respectively. In Fig. 52.1 (b), arrowhead indicates the conventional direction of current flow when forward-biased. It is the same direction in which hole flow takes place.
Commercially available diodes usually have some means to indicate which lead is P and which lead is N.
Standard notation consists of type numbers preceded by
‘IN’ such as IN 240 and IN 1250. Here, 240 and 1250 correspond to colour bands. Fig. 52.2 (a) shows typical diodes having a variety of physical structures whereas Fig.
52.2 (b) illustrates terminal identifications. Also refer to the picture of two commercial diodes shown in Fig 52.1(c).
(a)
P
N
(b)
Cathode
Anode
a
(c)
k
a
k
a
k
Fig. 52.1
Fig. 52.2
The low-current diodes whose body is about 3 mm long can carry a forward current of about
100 mA, have saturation current of 5 µA at room temperature (25ºC) and can withstand a reverse voltage of 75 V without breaking down. The medium-current diodes can pass a