7/24/2019 Ch05 Razavi
1/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Chapter 5Passive and Active Current Mirrors
7/24/2019 Ch05 Razavi
2/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Current Mirrors
IOUTunCox
2
W
L( R2
R2 + R1VDD VTH)
2
7/24/2019 Ch05 Razavi
3/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Reference Currents
7/24/2019 Ch05 Razavi
4/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Amplifier Bias Example
7/24/2019 Ch05 Razavi
5/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Cascode Current Mirror
7/24/2019 Ch05 Razavi
6/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Cascode Current Mirror (cont.)
7/24/2019 Ch05 Razavi
7/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Cascode Current Mirror (cont.)
7/24/2019 Ch05 Razavi
8/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Cascode Current Mirror Biasing
7/24/2019 Ch05 Razavi
9/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Active Current Mirror
7/24/2019 Ch05 Razavi
10/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Open Loop Constraints
C i h h G ill C i
7/24/2019 Ch05 Razavi
11/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Small-Signal Current Mirror
Av GmRout
C i h Th M G Hill C i I
7/24/2019 Ch05 Razavi
12/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Calculation of Gm
ID1 = ID3 = ID4 =gm1,2Vin/ 2 ID2 = gm1,2Vin/ 2
Iout =ID2 ID4 = gm1,2Vin ,Gm = gm1, 2
C i h Th M G Hill C i I
7/24/2019 Ch05 Razavi
13/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Calculation of Rout
IX =2 VX
2ro1, 2 +1/gm3+ VX
ro4
Rout ro2 || ro4 , (2ro1,2 >> [1/gm3] || ro3 )
C i h Th M G Hill C i I
7/24/2019 Ch05 Razavi
14/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Small-Signal Gain
Av gm1,2 (ro2 || ro4 )
C i ht Th M G Hill C i I
7/24/2019 Ch05 Razavi
15/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Common Mode Characteristics
ACM= Vout
Vin,CM
C i ht Th M G Hill C i I
7/24/2019 Ch05 Razavi
16/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Common Mode (cont.)
ACM
1
2gm3,4||ro3,4
21
2gm1,2+RSS
= 11 + 2gm1,2RSS
gm1,2
gm3, 4
C i ht Th M G Hill C i I
7/24/2019 Ch05 Razavi
17/17
Copyright The McGraw-Hill Companies, Inc.
University of Toronto ECE530 Analog Electronics
Common Mode (cont.)
CMRR =ADM
ACM
= gm1, 2(ro1,2|| ro3,4 )gm3,4 (1 + 2gm1,2RSS)
gm1,2
= gm3,4 (ro1, 2|| ro3,4 )(1 + 2gm1, 2RSS)
Recommended