Differential Amplifier
|
Components with nominal values |
|
|
BJTs |
BJT1-BJT4 (beta=80) |
|
Resistors |
Rc1=10KW ,
Rc2=10KW
|
Differential amplifier frequency response with nominal
component values.
|
Component variation table |
Nominal value |
Variation at 1s |
|
b |
80 |
12 |
|
Rc1 |
10KW |
0.5KW |
|
Rc2 |
10KW |
0.5KW |
|
Rs |
1KW |
50 W |
|
Rs2 |
1KW |
50 W |
|
Rbias |
20.0KW |
1KW |
Figure 24: Differential amplifier frequency response with component variation.
|
Hard fault table |
Fault |
No. of faults |
|
BJT1-BJT4 |
Stuck-open/stuck-short |
4x6=24 |
|
BJT1-BJT4 |
High-beta/low-beta |
2x4=8 |
|
Rc1,Rc2,Rs,Rs2,Rbias |
Stuck-open/stuck-short |
5x2=10 |
|
Total no. of faults: |
|
42 |
|
Soft fault table |
Nominal value |
- 6s |
+6s |
|
b |
80 |
6 |
152 |
|
Rc1-Rc2 |
10KW |
7.0KW |
13.0KW |
|
Rs, Rs2 |
1KW |
700 W |
1.3KW |
|
Rbias |
20.0KW |
14.0KW |
26.0KW |
*Differential
Amplifier
.SUBCKT QT1 1 2 3
RB1 2 12 1.0
RC1 1 11 1.0
RE1 3 13 1.0
RBC1 11 12 100meg
RBE1 12 13 100meg
RCE1 11 13 100meg
Q1 11 12 13 QNL1
* Q1 1 2 3 QNL1
.model QNL NPN(beta=80
cap_csb=2PF Cap_be=3PF
+Cap_ibc=2PF
)
.ENDS QT1
.SUBCKT QT2 1 2 3
RB2 2 12 1.0
RC2 1 11 1.0
RE2 3 13 1.0
RBC2 11 12 100meg
RBE2 12 13 100meg
RCE2 11 13 100meg
Q2 11 12 13 QNL2
* Q2 1 2 3 QNL2
.model QNL NPN(beta=80
cap_csb=2PF Cap_be=3PF
+Cap_ibc=2PF
)
.ENDS QT2
.SUBCKT QT3 1 2 3
RB3 2 12 1.0
RC3 1 11 1.0
RE3 3 13 1.0
RBC3 11 12 100meg
RBE3 12 13 100meg
RCE3 11 13 100meg
Q3 11 12 13 QNL3
* Q3 1 2 3 QNL3
.model QNL NPN(beta=80
cap_csb=2PF Cap_be=3PF
+Cap_ibc=2PF
)
.ENDS QT3
.SUBCKT QT4 1 2 3
RB4 2 12 1.0
RC4 1 11 1.0
RE4 3 13 1.0
RBC4 11 12 100meg
RBE4 12 13 100meg
RCE4 11 13 100meg
Q4 11 12 13 QNL4
* Q4 1 2 3 QNL4
.model QNL NPN(beta=80
cap_csb=2PF Cap_be=3PF
+Cap_ibc=2PF
)
.ENDS QT4
* MAIN CIRCUIT
RC1 3 4 10k
XQ2 1 6 10 QT2
XQ1 3 2 10 QT1
RC2 1 4 10K
RBIAS 4 7 20K
VCC 4 0 12
*VIN 5 0 0.0
VEE 8 0 -12.0
XQ3 10 7 8 QT3
XQ4 7 7 8 QT4
RS2 6 0 1K
RS 5 2 1K
Vin 5 0 ac 1
.ac dec 20 10
1g
.plot vdb(1)
.options list node post=2
.END