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Matakuliah
Tahun
Versi
: H0362/Very Large Scale Integrated Circuits
: 2005
: versi/01
Pertemuan 2
Karakteristik Kelistrikan Gerbang
MOSFET
1
Learning Outcomes
Pada Akhir pertemuan ini,
diharapkan mahasiswa akan dapat
menunjukkan karakteristik kelistrikan
gerbang MOSFET.
2
MOS Fisik
+ VG Gate voltage
Bentuk fisik
Gate
Gate oxide
Silicon surface
tox
+ VG > 0
p-type substrate
Silicon surface
QS surface charge
p-type
3
nFET
Bentuk fisik
3 dimensi
Gate
Gate
Gate oxide
Source
n+
n+
n+
L
Drain
Source
n+
Drain
p-substrate
Tampak samping
Tampak atas
4
nFET
G
Arus dan tegangan
VGSn +
S
-
-
IDn
VDSn +
D
-
VGSn
VDSn
+
IDn
Simbol
S
G
n+
D
n+
L
p-substrate
Struktur
5
nFET
VGSn  VTn
n+
VGSn > VTn kanal
n+
Source
n+
n+
Source
Drain
Qe = 0
Qe
Pengaturan kanal
Drain
Active
CUT off
VGSn < VTn
-
+
S
G
n+
VDSn
IDn = 0
D
n+
p-substrate
Cut off
VGSn > VTn
-
+
S
G
n+
VDSn
IDn mengalir
D
n+
p-substrate
Active
6
nFET
IDn
I-V characteristics
+
VDSn = VDD
+
VGSn
IDn
-
Cutoff
-
Active
VGSn
0
VTn
I-V fungsi VGSn
IDn
+
IDn
+
saturation
non
saturation
VDSn
VGSn > VTn
-
I-V fungsi VDSn
VDSn
0
Vsat
7
nFET
6
x 10
I-V characteristics
-4
VGS= 2.5 V
IDn
5
Resistive
3
Saturation
VGS= 2.0 V
VDS = VGS - VT
D
I (A)
4
2
VGS= 1.5 V
1
VGS= 1.0 V
0
0
0.5
1
1.5
V DS (V)
2
VDSn
2.5
8
nFET
CDB
CGS
RC model
CGD
CSB
n+
n+
S
Gate
Physical visualization
CGS
G
G
D
CD
CS
Linier model
CGD
D
S
CSB
Rn
CDB
Symbol diagram
9
pFET
Gate
Gate
p+
n+
p+
n-well
n+
np
pn
p-substrate
p-substrate
pFET
nFET
VSDp
G
+
IDp
-
VSDp
+
VSGp
G
S
-
D
-
IDp
+
p+
S
D
p+
+ VDD
n-well
n-well
p-substrate
Simbol
Struktur
10
pFET
IDp
+
VSFp
I-V characteristics
+
-
VSDp = VDD
Cutoff
-
IDn
Active
VSGp
0
VTn
-
VSGp  |VTn|
IDp = 0
S
G
p+
IDp
VSDp
S
p+
n-well
-
+
VSGp > |VTn|
+ VDD
n-well
S
G
p+
+
VSDp
S
p+
+ VDD
n-well
n-well
p-substrate
Cutoff
p-substrate
Active
11
DC Inverter
Vout
MP ON, Mn OFF
VOH = VDD
x
Vout = Vin
x
x
x
0
1
1
0
VM
Mn ON, Mp OFF
VOH = 0
0
VM
VIL
VDD
1 VDD
VIH
VDD
ON
+
Vin = 0
-
OFF
+
OFF
Vout = VDD
-
Low input voltage
+
Vin = VDD
-
+
ON
Vout = 0
-
High input voltage
12
DC Inverter
VDD
Switching characteristics
Vin
t
tf
VDD
tr
Vout
t
VDD
t2
t1
Rp
VDD
CDp
Mp
+
+
Vin
-
+
Mn
Inverter circuit
Vout
-
CDn
Vin
-
Rn
RC switch model
+
Vout
13
Power Dissipasi
VDD
IDD
Rangkaian
CMOS
P = VDD IDD
P = PDC + Pdyn
PDC: daya arus searah
Pdyn: daya akibat aktifitas switching
14
RESUME
• Bentuk fisik dan karakteristik nFET dan
pFET.
• Karakteristik DC inverter.
• Karakteristik switch inverter.
• Power dissipasi
15