LT1251/LT1256
W
W
ACRO ODEL
*full scale amp
IBFS
RIFS
C12
12
12
12
12
0
0
0
–300NA
100MEG
1PF
1600
10PF
12A
–5MV
1PF
5K
R12
12A
0
CBWFS 12A
EFS 12B
VOSFS 12B
C11
RFS
C10
*
0
0
1.0
11
0
11
11
10
10
0
1PF
*generating K
*** the next two lines are for the LT1251
EK K 0 TABLE {I(VOSC)/I(VOSFS)}= (–100,0)
(0.04,0)
(0.1,0.11)
+
(0.9,0.907)(0.95,1.0) (100,1.0)
*** the next two lines are for the LT1256
*EK K 0 TABLE {I(VOSC)/I(VOSFS)}= (–100,0)
*+
(0,0)
(0.2,0.21)
(100,1.0)
(0.9,0.9)
(1.0,1.0)
RDUMMY
RNOISE1 EN
RNOISE2 EN
K
0
0
0
1MEG
200K
200K
*generates 40.7nV/rtHz
*
*null circuit
GNULL
RN1
VNULL
RN2
C6
7
6A
6A
6B
6
6A
7
6B
6
VALUE={I(VOSFS)}
200
0.0V
400
1PF
7
*
*output stage
E6 8A
0
+VALUE={1.8MEG*(I(VOS1)*V(K)+I(VOS2)*(1–V(K))–I(VNULL)+0.10UA+0.0007*V(EN))}
RG
CG
E8
V8
R8
*
8A
8B
8C
8C
8D
8B
0
0
8D
8
1.8MEG
3.4PF
8B
0.0V
11
0
1.0
*output swing and current limit
DP
VDP
DN
VDN
.MODEL
GCL
*
8B
8P
8N
8N
D1
8B
8P
9
8B
7
D
0
D1
–1.4V
D1
1.4V
TABLE {I(V8)}=(–1,–1)(–0.04,0)(0.04,0)(1,1)
*supply current
GQ
9
9
7
7
0
0
VALUE={1MA+24*I(VOSFS)+(V(7)–V(9))/20K}
TABLE {I(V8)}=(–1,0)(0,0)(1,1)
TABLE {I(V8)}=(–1,–1)(0,0)(1,0)
GCC
GEE
*
.ENDS LT1251
21
Linear [ Linear ]
