Datasheet

5
LT1251/LT1256
CONTROL VOLTAGE (V)
0
GAIN (V/V)
1.0
0.8
0.6
0.4
0.2
0
2.0
1251/56 G01
0.5
1.0
1.5
2.5
V
FS
= 2.5V
IN2
IN1
TYPICAL PERFORMANCE CHARACTERISTICS
UW
LT1251/LT1256
Control Path Bandwidth
FREQUENCY (Hz)
VOLTAGE GAIN (dB)
10
8
6
4
2
0
–2
–4
–6
–8
–10
10k 1M 10M 100M
1251/56 G04
100k
VOLTAGE DRIVE V
C

V
S
= ±5V
PIN 4 NOT IN SOCKET
THD Plus Noise vs Frequency
FREQUENCY (Hz)
0.01
THD + NOISE (%)
0.1
1
10
10 1k 10k
1251/56 G08
0.001
100
100k
V
C
CC = 10%
V
C
CC = 50%
V
C
CC = 100%
V
S
CC = ±5V, V
IN
= 1V
RMS

A
V
= 1, R
F
= 1.5k, V
FS
= 2.5V
CONTROL VOLTAGE (V)
0
GAIN (V/V)
1.0
0.8
0.6
0.4
0.2
0
2.0
1251/56 G02
0.5
1.0
1.5
2.5
V
FS
= 2.5V
IN2
IN1
FREQUENCY (Hz)
100k
OUTPUT VOLTAGE (V
P-P
)
8
7
6
5
4
3
2
1
1M 10M 100M
1251/56 G07
A
V
= 10
A
V
= 1
V
S
= ±5V
R
L
= 1k
R
F
= 1.5k
V
C
= V
FS
= 2.5V
Undistorted Output Voltage
vs Frequency
FREQUENCY (Hz)
VOLTAGE GAIN (dB)
10
8
6
4
2
0
–2
–4
–6
–8
–10
10k 1M 10M 100M
1251/56 G05
100k
VOLTAGE DRIVE R
C

V
C
= GND
V
S
= ±5V
LT1251/LT1256
Control Path Bandwidth
FREQUENCY (MHz)
05
3RD ORDER INTERCEPT (dBm)
10 2015
25
30
1251/56 G10
50
45
40
35
30
25
20
15
10

V
S
CC = ±15V
A
V
= 1
R
F
= 1.5k
R
L
= 100Ω
V
C
= V
FS
= 2.5V
3rd Order Intercept vs Frequency
2nd and 3rd Harmonic Distortion
vs Frequency
FREQUENCY (MHz)
1
DISTORTION (dBc)
–20
–30
–40
–50
–60
–70
10 100
1251/56 G09
V
S
CC = ±5V
A
V
= 1
R
F
= 1.5k
R
L
= 1k
V
O
= 2V
P-P
V
C
= V
FS
= 2.5V
3RD
2ND
FREQUENCY (Hz)
10
1
10
100
100 1k 10k
1251/56 G06
SPOT NOISE (nV/√Hz OR pA/√Hz)
+i
n
e
n
–i
n
Spot Input Noise Voltage and
Current vs Frequency
LT1251
Gain vs Control Voltage
LT1256
Gain vs Control Voltage