Basic Current Mirrors and Single‐ - KNTU › shamsi › IC › Slide2.pdf · Microsoft PowerPoint...
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Basic Current Mirrors and Single‐Basic Current Mirrors and Single‐Stage Amplifiersg p
Hossein ShamsiHossein Shamsi
١
Simple Current Mirror
dsout
Wrr
⎞⎜⎛
= 2
inout IWLW
I⎞⎛⎠⎞
⎜⎝⎛
= 2inout
LW
⎟⎠⎞
⎜⎝⎛
1
effout VV ≥
٢
Common‐Source Amplifier
٣
Source‐Follower or Common‐Drain Amplifier
gs1 denotes the body effect. (gs1 =gmb1)gs1 denotes the body effect. (gs1 gmb1)
۴
Common‐Gate Amplifier
2dsL rR =
۵
Common‐Gate Amplifier
۶
Source‐Degenerated Current Mirrors
inout IILW
LWif =⇒⎟
⎠⎞
⎜⎝⎛=⎟
⎠⎞
⎜⎝⎛
21 LL ⎠⎝⎠⎝ 21
effoutsout VIRV +≥
٧
High‐Output‐Impedance Current Mirrors
Cascode Current Mirror Wilson Current Mirror
٨
Cascode Current Mirror
ILW
I 2
⎟⎠⎞
⎜⎝⎛
= inout I
LW
I
1
⎟⎠⎞
⎜⎝⎛
=
٩
Wilson Current Mirror
LW
⎟⎠⎞
⎜⎝⎛
inout I
LWLI 2
⎟⎠⎞
⎜⎝⎛
⎠⎝=
L 1⎠⎝
١٠
CASCODE Gain Stage
telescopic-cascode amplifier folded-cascode amplifier
١١
Telescopic‐Cascode Amplifier
RR ||
outmV
Ldout
RgARrR×−≅
=
1
2 ||
The folded-cascode amplifier is analyzed similarly.
١٢
Differential PairDifferential PairAfter a few manipulation, it i th t
rrr ≅
is proven that:
24 dsdsout rrr ≅
Besides, we have:
i vgv
gii 22≅ immssc vggii 111 222 ==≅
So the voltage-gain is obtained:So, the voltage gain is obtained:
outmV rgA =
Frequency ResponseCommon‐Source AmplifierCommon Source Amplifier
١۴
Frequency ResponseCommon‐Source Amplifierp
Assuming that poles are real numbers and ωp1<< ωp2, we have:
١۵
Frequency ResponseCommon‐Source Amplifierp
If the poles are complex conjugate, we will write the above transfer function as follows:
( ) RgA m−=0 21
b=
10ω
abQ =
Si il l l th C D d C G lifi
١۶
Similarly, we can analyze the C.D and C.G amplifiers.
Frequency ResponseCASCODE Amplifierp
p CRCR11
1 ≅≅ω
2mg≅ω
Loutdoutp CRCR 21
22
sp C≅ω
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