Analog Electronics ppt on Diodes by Being topper

1. DIODES
ANALOG ELECTRONIC
AMITENDRA KUMAR
IT 3RD SEMESTER
00620703111

2. IDEAL DIODE
• Its is the two terminal device and permits only
undirectional conduction. It conduct well in
the forward direction and poorly in the
reverse direction. It would have been ideal if it
acted as a perfect conductor when forward
bias and as a perfect insulator when reverse
biased. An ideal diode act like an automatic
switch. The switch is Closed when the diode is
forward biased and is opened when reverse
biased.

3. Ideal Diode
No diode can Act as an ideal diode.
An actual diode does not behave as a perfect
conductor when forward biased and as a perfect
insulator when reverse biased. Neither it offered
zero resistance when forward biased nor infinite
resistance when reverse biased

4. V-I characteristics of an ideal
diode
The diode forward current I is usually so much
larger than the reverse saturation current IO that
the IO can just be ignored. These assumptions lead
to a nearly ideal or approximate characteristic for
Germanium and silicon diode as in figure.

5. SCHOTTKY DIODE
A Diode has no depletion layer eliminating the stored
charges at the junction. Because of lack of charge
storage the Schottky diode can switch off faster than
an ordinary diode.A schottky diode can easily rectify
frequencies exceeding 300MHz.
Construction of schottky diode
The construction is very different from the normal P-N junction in that
a metal semiconductor junction is developed. On one side of the
junction a metal is used and on the other side of the junction N-type
doped silicon is used.in general, schottky diode construction result in
more uniform junction region and increased ruggedness compared to a
point contact diode –its main rival.

6. SCHOTTKY BARRIER
• The level of minority carriers (holes) is insignificant.
When the diode is unbiased,electron on the N-side
have low energy levels than electron in the metal and
so the electron cannot cross the junction barrier.
HOT-CARRIER DIODE
• The diode is forward biased ,the electron on the N-side
gain enough energy to across the junction and enter
the metal . Since these electron plunge into the metal
with very large energy ,they are usually called hot
carriers and the diode is called the hot carriers diode.

7. EQUIVALENT CIRCUIT OF
SCHOTTKY DIODE

8. V-I CHARACTERSTICS OF
SCHOOTKY DIODE