Transcript Document

Analog Circuit Design
Lesson 12
Mixer
1
A mixer is a circuit which multiplies two signals
.
f1 (t ) and f 2 (t )
That is, if the inputs are cos(2f1t ) and cos(2f 2t ) ,
output will be cos(2f1t ) cos(2f 2t ).
2
VDD=1.5v
R1=130k
M1
120u/6u
R2=130k
Vout
M2
120u/6u
V1
V2
M3
100u/2u
VGS=-0.98v
Vss=-1.5v
3
M3 accepts V2 which is a signal with low
frequency, probably human voice signal or music
signal. Its amplitude, on the other hand, is
rather large.
V1 is a signal with high frequency and small
amplitude.
4
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mixer
.protect
.lib 'c:\mm0355v.l' TT
.unprotect
.op
.options post
+nomod acct list
•
•
•
•
•
•
•
•
•
•
VDD
VSS
R1
R2
.param
.param
M1
.param
.param
M2
8
2
8
8
W1=120u
L1=6u
6
W2=120u
L2=6u
7
•
•
•
.param
.param
M3
•
•
•
•
•
•
0
0
6
7
1.5v
-1.5v
130k
130k
4
3
3
nch L='L1'
W='W1' m=1
5
3
3
nch L='L2'
W='W2' m=1
W3=100u
L3=2u
3
1
2
2
nch L='L3'
W='W3' m=1
VG2
ViP
ViN
1
4
0
0
0
5
SIN(-0.98v 0.06v 500k)
SIN(0v 0.005v 10Meg)
SIN(0v 0.005v 10Meg)
.tran
.plot
.end
0.01us
V(6,7) V(4,5)
10000ns
5
V1
V2
Vout
6
• V1=0
• V2=SIN(-0.98v 0.06v 500k)
7
mixer
.protect
.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
.param
.param
M1
.param
.param
M2
.param
.param
M3
W1=120u
L1=6u
6
W2=120u
L2=6u
7
W3=100u
L3=2u
3_3
VG2
ViP
ViN
1
4
0
.tran
.plot
0.01us
10000ns
V(3) V(6,3) V(7,3) V(4,3) V(5,3)
4
VDD=1.5v
8
R1=130k
1.5v
-1.5v
130k
130k
0k
3
M1
120u/6u
R2=130k
6
7
Vout
4
5
3
V1
3
R3=0k
3_3
3 nch L='L1‘ W='W1' m=1
M3
100u/2u
1
V2
5
M2
120u/6u
3 nch L='L2‘ W='W2' m=1
VGS=-0.98v
2 nch L='L3‘ W='W3' m=1
1
2
0
0
5
SIN(-0.98v 0.06v 500k)
0
0
2
Vss=-1.5v
8
.end
V2
VDS1
VDS2
VGS1
VGS2
9
mixer
.protect
.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
.param
.param
M1
.param
.param
M2
.param
.param
M3
W1=120u
L1=6u
6
W2=120u
L2=6u
7
W3=100u
L3=2u
3_3
VG2
ViP
ViN
1
4
0
.tran
.plot
0.01us
10000ns
V(3) I(R1) I(R2) I(R3)
4
VDD=1.5v
8
R1=130k
1.5v
-1.5v
130k
130k
0k
3
M1
120u/6u
R2=130k
6
7
Vout
4
5
3
V1
3
R3=0k
3_3
3 nch L='L1‘ W='W1' m=1
M3
100u/2u
1
V2
5
M2
120u/6u
3 nch L='L2‘ W='W2' m=1
VGS=-0.98v
2 nch L='L3‘ W='W3' m=1
1
2
0
0
5
SIN(-0.98v 0.06v 500k)
0
0
2
Vss=-1.5v
10
.end
V2
IDS1
IDS2
IDS3
11
• The above result shows that V2 causes the
VDS’s of all transistors to be sinusoidal.
• Even the VGS’s of M1 and M2 are now
sinusoidal.
12
• In the following, we make both V1 and V2
• sinusoidal.
• V1=SIN(0v 0.005v 10Meg)
• V2=SIN(-0.98v 0.06v 500k)
13
mixer
.protect
.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
.param
.param
M1
.param
.param
M2
.param
.param
M3
W1=120u
L1=6u
6
W2=120u
L2=6u
7
W3=100u
L3=2u
3_3
VG2
ViP
ViN
1
4
0
.tran
.plot
0.01us
10000ns
V(3) V(6,3) V(7,3) V(4,3) V(5,3) V(6,7)
4
VDD=1.5v
8
R1=130k
1.5v
-1.5v
130k
130k
0k
3
M1
120u/6u
R2=130k
6
7
Vout
4
5
3
V1
3
R3=0k
3_3
3 nch L='L1‘ W='W1' m=1
M3
100u/2u
1
V2
5
M2
120u/6u
3 nch L='L2‘ W='W2' m=1
VGS=-0.98v
2 nch L='L3‘ W='W3' m=1
1
2
0
0
5
SIN(-0.98v 0.06v 500k)
SIN(0v 0.005v 10Meg)
SIN(0v 0.005v 10Meg)
2
Vss=-1.5v
14
.end
V2
VDS1
VDS2
VGS1
VGS2
Vout
15
• We can see that
• VDS1=V2-V1 and VGS1=-(V2-V1).
• VDS2=V2+V1 and VGS2=-(V2+V1).
• In other words, M1 and M2 are influenced
by both V2 and V1.
16
• In the following, we shall display V6 and V7.
17
mixer
.protect
.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
.param
.param
M1
.param
.param
M2
.param
.param
M3
W1=120u
L1=6u
6
W2=120u
L2=6u
7
W3=100u
L3=2u
3_3
VG2
ViP
ViN
1
4
0
.tran
.plot
0.01us
10000ns
V(3) V(6) V(7) V(6,7)
4
VDD=1.5v
8
R1=130k
1.5v
-1.5v
130k
130k
0k
3
M1
120u/6u
R2=130k
6
7
Vout
4
5
3
V1
3
R3=0k
3_3
3 nch L='L1‘ W='W1' m=1
M3
100u/2u
1
V2
5
M2
120u/6u
3 nch L='L2‘ W='W2' m=1
VGS=-0.98v
2 nch L='L3‘ W='W3' m=1
1
2
0
0
5
SIN(-0.98v 0.06v 500k)
SIN(0v 0.005v 10Meg)
SIN(0v 0.005v 10Meg)
2
Vss=-1.5v
18
.end
V2
V6
V7
Vout
19
V6
V7
20
mixer
.protect
.lib 'c:\flexlm\model\tsmc\MIXED035\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
.param
.param
M1
.param
.param
M2
.param
.param
M3
W1=120u
L1=6u
6
W2=120u
L2=6u
7
W3=100u
L3=2u
3_3
VG2
ViP
ViN
1
4
0
.tran
.plot
0.01us
10000ns
I(R1) I(R2) I(R3)
4
VDD=1.5v
8
R1=130k
1.5v
-1.5v
130k
130k
0k
3
M1
120u/6u
R2=130k
6
7
Vout
4
5
3
V1
3
R3=0k
3_3
3 nch L='L1‘ W='W1' m=1
M3
100u/2u
1
V2
5
M2
120u/6u
3 nch L='L2‘ W='W2' m=1
VGS=-0.98v
2 nch L='L3‘ W='W3' m=1
1
2
0
0
5
SIN(-0.98v 0.06v 500k)
SIN(0v 0.005v 10Meg)
SIN(0v 0.005v 10Meg)
2
Vss=-1.5v
21
.end
IDS1
IDS2
IDS3
22
VDD=1.5v
Note that
8
R1=130k
I DS  C(VGS  Vt )VDS .
M1
120u/6u
R2=130k
6
7
Vout
4
With both V1 and V2, we have
5
Thus, we have
I ds1  C ((V2  V1 )  Vt )(V2  V1 ),
V1
3
Vgs1  (V2  V1 ), Vgs 2  (V2  V1 )
Vds1  V2  V1 , Vds 2  V2  V1.
M2
120u/6u
R3=0k
3_3
M3
100u/2u
1
V2
VGS=-0.98v
2
Vss=-1.5v
I ds 2  C ((V2  V1 )  Vt )(V2  V1 ),
23
V6   K (V2  V1 ) 2  KVt (V2  V1 )
V7   K (V2  V1 )  KVt (V2  V1 )
2
Vout  V7  V6  4 KV1V2  2 KV1  4 KV1V2
VDD=1.5v
8
R1=130k
M1
120u/6u
R2=130k
6
7
Vout
4
M2
120u/6u
5
V1
3
R3=0k
3_3
M3
100u/2u
1
V2
VGS=-0.98v
2
24
Vss=-1.5v
•
•
•
•
•
•
mixer5
.protect
.lib 'c:\mm0355v.l' TT
.unprotect
.op
.options post nomod acct list
•
•
•
•
•
VDD
VSS
R1
R2
R3
8
2
8
8
3
0
0
6
7
3_3
1.5v
-1.5v
130k
130k
0k
•
•
•
.param
.param
M1
m=1
.param
.param
M2
m=1
.param
.param
M3
m=1
W1=120u
L1=6u
6
4
3
•
•
•
VG2
ViP
ViN
1
4
0
•
•
.tran
.plot
0.01us
10000ns
V(3) V(6,3) V(7,3) V(4,3) V(5,3) V(6,7)
•
.end
•
•
•
•
•
•
VDD=1.5v
8
R1=130k
M1
120u/6u
2 nch L='L1' W='W1'
W2=120u
L2=6u
7
5
3
2 nch L='L2' W='W2'
W3=100u
L3=2u
3_3
1
2
2 nch L='L3' W='W3'
R2=130k
6
7
Vout
4
M2
120u/6u
5
3
V1
-V1
M3
100u/2u
1
0
0
5
SIN(-0.98v 0.06v 500k)
SIN(0v 0.005v 10Meg)
SIN(0v 0.005v 10Meg)
R3=0k
3_3
V2
VGS=-0.98v
2
Vss=-1.5v
25
V1
V2
V3
VDS1
VDS2
VGS1
VGS2
VDS3
Vout
26
-V1
V2
VDS1
27
V1
V2
VDS2
28
VDD=1.5v
•
•
•
•
mixer1
.PROTECT
.LIB "C:\mm0355v.l" TT
.UNPROTECT
•
•
•
VDD 1
VSS 12
Rm 1
0
0
11
•
M1
•
M3
2
3
3
W=120U L=6U
4
12
12
W=100U L=2U
11
NCH
3
NCH
R1=130k
M1
120u/6u
1.5V
-1.5V
65k
•
•
•
V1 2
0
SIN(0v 0.005v 10Meg)
V2 4
0
SIN(-0.98v 0.06v 500k)
.plot V(11,3) V(2,3) V(3,12) I(Rm)
•
•
.tran 0.1ns 4us
.END
11
2
V1
3
4
V2
M3
100u/2u
12
VGS=-0.98v
Vss=-1.5v
29
V1
V2
VDS1
VGS1
30
•
•
•
•
•
•
•
•
mixer1
.PROTECT
.LIB "C:\mm0355v.l" TT
.UNPROTECT
.op
VDD 1
0
1.5V
VSS 12
0
-1.5V
Rm 1
11
65k
•
M1
•
M3
11
NCH
3
NCH
2
3
0
W=100U L=6U
4
12
0
W=100U L=6U
•
•
•
V1 2
0
SIN(0v 0.005v 10Meg)
V2 4
0
SIN(-0.95v 0.06v 500k)
.plot V(11,3) V(2,3) V(3,12) I(Rm)
•
.tran 0.1ns 5us
VDD=1.5v
R1=65k
M1
100u/6u
11
2
V1
3
4
V2
M3
100u/2u
12
VGS=-0.98v
Vss=-1.5v
•
.END
31
V1
V2
V3
VDS1
VGS1
VDS3
32