Datasheet

21
LT1251/LT1256
ACRO ODEL
WW
*full scale amp
IBFS 12 0 –300NA
RIFS 12 0 100MEG
C12 12 0 1PF
R12 12 12A 1600
CBWFS 12A 0 10PF
EFS 12B 0 12A 0 1.0
VOSFS 12B 11 –5MV
C11 11 0 1PF
RFS 11 10 5K
C10 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)
*+ (0.9,0.9) (1.0,1.0) (100,1.0)
RDUMMY K 0 1MEG
RNOISE1 EN 0 200K
RNOISE2 EN 0 200K
*generates 40.7nV/rtHz
*
*null circuit
GNULL 7 6A VALUE={I(VOSFS)}
RN1 6A 7 200
VNULL 6A 6B 0.0V
RN2 6B 6 400
C6 6 7 1PF
*
*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 8A 8B 1.8MEG
CG 8B 0 3.4PF
E8 8C 0 8B 0 1.0
V8 8C 8D 0.0V
R8 8D 8 11
*
*output swing and current limit
DP 8B 8P D1
VDP 8P 9 –1.4V
DN 8N 8B D1
VDN 8N 7 1.4V
.MODEL D1 D
GCL 8B 0 TABLE {I(V8)}=(–1,–1)(–0.04,0)(0.04,0)(1,1)
*
*supply current
GQ 9 7 VALUE={1MA+24*I(VOSFS)+(V(7)–V(9))/20K}
GCC 9 0 TABLE {I(V8)}=(–1,0)(0,0)(1,1)
GEE 7 0 TABLE {I(V8)}=(–1,–1)(0,0)(1,0)
*
.ENDS LT1251