KUL-ELDAS2-dioda2

8/13/2019 KUL-ELDAS2-dioda2

1/68

Kuliah Elektronika DasarMinggu ke 2

DIODA

Jurusan Teknik Elektro

Fakultas Teknik UGM2008


2/68

FUNCTION

Electrical gate Current only flows one way

Forward biasedCurrent flows

Reverse biasedBlocks current

+ -

- +


3/68

pn junction diode I-V characteristics

-10

-5

0

5

10

15

20

-6 -5 -4 -3 -2 -1 0 1 2 3 4

Applied voltage

C u r r e n t

KARAKTERISTIK DIODAArus-Teg ( I-V )

Tegangan Maju

Tegangan Balik

Tegangan Breakdown

Arus Balik Jenuh 0.7V Switch-on


4/68

PN CONSTRUCTION

Semiconductor materialn-type

Excess electrons

p-typeExcess holes

Join together

Depletion regionRedistribution of charge carriersContact potential

0.7V


5/68

Bahan Jenis P Bahan Jenis N

SAMBUNGAN PN

Holes berdifusi ke jenis N

Electrons berdifusi ke jenis P

Terbentuk Daerah Deplesi Tak ada pembawa muatanTerjadi tegangan Kontak 0,7 V


6/68

FORWARD BIAS

Applied voltage above0.7V

depletion region is

removedcharge carriers can flow

V< 0.7V V> 0.7V

P N

+ +

Depletion regionnarrows as appliedvoltage approaches 0.7V

Depletion Region

DAERAH DEPLESI MENYEMPIT MENGHILANG


7/68

TEGANGAN MAJU

Lebih besar 0.7 VDaerah Deplesi menghilangTerjadio Aliran Pembawa

Muatan

V sekitar 0.7 VV> 0.7V

Daerah Delesimenyempit

DAERAH DEPLESI MENYEMPIT MENGHILANG


8/68

TEGANGAN BALIK

Daerah Deplesi MelebarKalau Tegangan Balik bertambah

Terjadi Breakdown Arus Mengalir

V< 0V V


9/68

Bohr model(I hope its not bohring)

The Bohr model is aplanetary model, where theelectron orbits the nucleus

like a planet orbits the Sun. An electron is only allowed inDISCRETE orbits (n=1, n=2,n=3, etc.)The higher the orbit, thehigher the energy of theelectron.


10/68

Model Bohr (Sebuah Atom)


11/68

MODEL BOHR (Sebuah Atom)


12/68

PITA ENERGI (Sebuah Atom)

PITA HANTARAN

PITA VALENSI

CELAH ENERGI

INTI


13/68

PITA ENERGI

PITAHANTARAN

PITA VALENSI

PITAHANTARAN

PITA VALENSI PITA VALENSI

PITAHANTARAN Large Gap

No Gap

Small Gap

SemikonduktorLogamIsolator


14/68

ELEKTRON DI ORBIT TERLUAR

SiliconTetravalent

BoronTrivalent

Acceptor

PhosphorusPentavalent

Donor


15/68

PITA ENERGI

PITA HANTARAN

PITA VALENSI elektron

celah energi


16/68

TERBENTUKNYA HOLE

elektron

PITA HANTARAN

ELEKTRON BEBAS

HOLE

ENERGITAMBAHAN

Jumlah Elektron Bebas = Jumlah Hole

PITA VALENSI


17/68


18/68

P-N JUNCTION FORMATION

p-type material

Contains NEGATIVELYcharged acceptors(immovable) andPOSITIVELY chargedholes (free).

Total charge = 0

n-type material

Contains POSITIVELYcharged donors(immovable) and

NEGATIVELYcharged free electrons.

Total charge = 0


19/68

p-type material

Contains NEGATIVELYcharged acceptors(immovable) andPOSITIVELY chargedholes (free).

Total charge = 0

n-type material

Contains POSITIVELYcharged donors(immovable) and

NEGATIVELYcharged free electrons.

Total charge = 0

What happens if n- and p-type materials are in close contact ?P-N JUNCTION FORMATION


20/68

p- n junction formation

What happens if n- and p-type materials are in close contact?

Being free particles, electrons start diffusing from n-type material into p-material

Being free particles, holes, too, start diffusing from p-type material into n-material

Have they been NEUTRAL particles, eventually all the freeelectrons and holes had uniformly distributed over the entirecompound crystal.

However, every electrons transfers a negative charge (-q) ontothe p-side and also leaves an uncompensated (+q) charge of thedonor on the n-side.Every hole creates one positive charge (q) on the n-side and (-q)

-


21/68

p- n junction formation

What happens if n- and p-type materials are in close contact?

Electrons and holes remain staying close to the p-n junction becausenegative and positive charges attract each other.

Negative charge stops electrons from further diffusion

Positive charge stops holes from further diffusion

The diffusion forms a dipole charge layer at the p-n junction interface.

There is a built -in VOLTAGE at the p -n junction interface that preventspenetration of electrons into the p-side and holes into the n-side.

p-type n-type


22/68

p- n junction current voltage characteristicsWhat happens when the voltage is applied to a p-n junction?

The polarity shown, attracts holes to the left and electrons to the right.

According to the current continuity law, the current can only flow if allthe charged particles move forming a closed loop

However, there are very few holes in n-type material and there arevery few electrons in the p-type material.There are very few carriers available to support the current through the

junction plane

For the voltage polarity shown, the current is nearly zero

p-type n-type


23/68

p- n junction current voltage characteristics

What happens if voltage of opposite polarity is applied to a p-n junction?

The polarity shown, attracts electrons to the left and holes to the right.

There are plenty of electrons in the n-type material and plenty of holes inthe p-type material.

There are a lot of carriers available to cross the junction.

When the voltage applied is lower than the built-in voltage,the current is still nearly zero

p-type n-type

When the voltage exceeds the built-in voltage, the current can flow through

the p-n junction


24/68

Diode current voltage (I-V) characteristics

1kT qV

I I S exp

p n

Semiconductor diode consists of a p-n junction with twocontacts attached to the p- and n- sides

IS is usually a very small current, I S 10 -17 10 -13 A

When the voltage V is negative (reverse polarity) the exponential term -1;The diode current is IS ( very small).

0V

When the voltage V is positive (forward polarity) the exponential term

increases rapidly with V and the current is high.

qkT

V T


25/68

q : muatan satu elektron =1,6 x 10 -19 C

k : konstanta boltzman =1,380 x 10 -23 J/K

T : derajat KelvinV : tegangan terpasang


26/68


27/68

p-type material

Semiconductor materialdoped with acceptors .

Material has high holeconcentration

Concentration of freeelectrons in p-type materialis very low.

n-type material

Semiconductor materialdoped with donors .

Material has highconcentration of freeelectrons.

Concentration of holes inn-type material is very low.

p-n junction formation


28/68

IKATAN KOVALENT


29/68

SILIKON DIPANASI


30/68

DI DOPING ATOM BERVALENSI 5

ION POS

BAHANN


31/68


BAHANP

ION NEG


32/68


ION POS

BAHANN


33/68


34/68

BAGAIMANA MEMBUAT BAHAN N ?

Bahan silikon diberi doping atom bervalensi 5(misal : pospor)

Uap pospor

Si N

Atom pospor disebut DONOR

RUANG HAMPA


35/68

Bahan semikonduktor jenis P

Bahan silikon diberi doping atom bervalensi 3(misal : boron)

Uap boron

Si P

Atom boron disebut ASEPTOR

RUANG HAMPA


36/68

DISTRIBUSI HOLE


37/68

TEGANGAN KONTAK

R D A

s V V N N q

W

0

112

20 lni

D AT n

N N V V


38/68

Simbul dioda dan arah arus

Karakteristik ideal

Rangkaian ekivalen saat reverse bias Rangkaian ekivalen saat forward bias


39/68

PENDEKATAN IDEAL


40/68

p- n diode applications:current rectifiers

1 pkT qV

IS

1 pkT qV

IS

+-

Time

Voltage

+

-

Time

Current

PENYEARAH


41/68

PENYEARAHsetengah gelombang

Saat forward

Saat reverse

Tegangan input

Tegangan output

0 2


42/68

TEGANGAN DC RATA-RATA

Mengintegralkansatu periode

2

0sin2

1d V V m DC

2

0

sin2

d V

V m DC

0cos2 m

DC V

V

mm DC

V V V 11

2

2

VDC


43/68

Bila ada tegangan lawan


44/68

Contoh rangkaian dioda


45/68


46/68

PENGARUH PANAS


47/68


48/68


49/68

MODEL DIODA DENGAN r D


50/68

DIODA TANPA r D


51/68

DIODA TANPA r D


52/68


53/68

POWER SUPPLYCATU DAYA


54/68

PENYEARAH


55/68

PENYEARAHGELOMBANG PENUH


56/68

TRAFO TANPA CENTER TAP(PENYEARAH BRIDGE )


57/68

FILTER C


58/68

PENGARUH BEBAN R L


59/68


60/68

CLIPPER (PEMANGKAS )

V in : tegangan sinus

V out

V in D 1 D 2

L + L -


61/68

PR

V in

adalah tegangan kotak 10 Volt


62/68

PENGGESER DAN PENGARUH R


63/68

PENGGANDA TEGANGAN

TEGANGAN PADA D1

PENGHASIL TEGANGAN GANDA


64/68

PENGHASIL TEGANGAN GANDA(DUAL SUPPLY )


65/68

PR

Gambar di slide 61, D2 dan D3diganti dengan R.

Gambarkan tegangan output V+terhadap ground.Bila R = 1K Ohm berapakah besar

nilai tegangan output itu.


66/68

JEMBATAN

I

PLN

A

D

C

B

PENYEARAH


67/68

PENYEARAHSEPAROH GELOMBANG

7,02 S P V V

F L P dc C R

V V 00833,0

1

F L

P r C R

V V

0048,0

V

t

PENYEARAH


68/68

GELOMBANG PENUH

7,0707,0 s P V V

F L P dc C R

V V 00417,0

1

FL

P r CR

V V

0024,0

V

t

KUL-ELDAS2-dioda2

Documents