LT1251/LT1256
U
TYPICAL APPLICATIONS
AM Modulator with DC Output Nulling Circuit
0.1µF
LT1256
1
14
13
12
11
10
9
1MHz
CARRIER
+
–
+
–
1
2
50Ω
2
CONTROL
220k
3
2.5VDC
INPUT
+
–
+
–
I
FS
I
0.1µF
C
FS
5k
C
4
5
AUDIO
MODULATION
R
R
F1
1.5k
F2
1.5k
5k
220k
NULL 6
+
V
7
8
–
V
OUT
V
220k
+
V
0.1µF
–
LT1077
+
1251/56 TA03
–
V
Single Supply Noninverting AC Amplifier
with Digital Gain Control
Single Supply Inverting AC Amplifier
C1
10µF
R
R
G1
F1
1.5k
R
G1
1.5k
R
F1
1.5k
1.5k
10µF
+
V1
+
LT1251/LT1256
2
1
LT1251/LT1256
R1
20k
–
+
2
1
1
–
+
+
V
1
10µF
8
9
7
+
V1
R2
C
V
OUT
O
8
9
7
+
14
13
V
OUT
20k
10µF
+
–
+
–
V
V
5V
10µF
14
13
+
–
2
+
–
V
V
5V
V2
5V
+
20k
2
10k
10k
V
C
R
R
V
FS
C
FS
V
C
R
C
R
FS
V
FS
3
5
10 12
+
3
5
10 12
20k
10µF
2.5VDC
INPUT
CONTROL
VOLTAGE
C2
10µF
R
R
1.5k
F2
10µF
G2
1.5k
+
+
V2
R
R
1251/56 TA05
G2
F2
1.5k
1.5k
V
REF
D
IN
CLK
µP
LTC1257
V
OUT
LOAD
GND
V
CC
1251/56 TA06
5V
15
Linear [ Linear ]
