LT1252
Low Cost
Video Amplifier
FEATURES
s
s
s
s
s
s
s
s
DESCRIPTIO
Low Cost
Current Feedback Amplifier
Differential Gain: 0.01%, R
L
= 150Ω, V
S
=
±5V
Differential Phase: 0.09°, R
L
= 150Ω, V
S
=
±5V
Flat to 30MHz, 0.1dB
100MHz Bandwidth on
±5V
Wide Supply Range:
±2V(4V)
to
±14V(28V)
Low Power: 85mW at
±5V
The LT1252 is a low cost current feedback amplifier for
video applications. The LT1252 is ideal for driving low
impedance loads such as cables and filters. The wide
bandwidth and high slew rate of this amplifier make
driving RGB signals between PCs and workstations easy.
The linearity of the LT1252 is outstanding; it is unsur-
passed for driving composite video.
The LT1252 is available in the 8-pin DIP and the S8 surface
mount package. For higher performance and shutdown
operation, see the LT1227. For dual and quad amplifiers
with similar performance see the LT1253/LT1254.
APPLICATI
s
s
s
S
RGB Cable Drivers
Composite Video Cable Drivers
Gain Blocks in IF Stages
TYPICAL APPLICATI
5V
V
IN
+
Transient Response
75Ω
LT1252
–
–5V
R
F
620Ω
V
OUT
R
G
620Ω
75Ω
75Ω
CABLE
A
V
= 1
+
R
F
BW = 100MHz
R
G
AT AMPLIFIER OUTPUT.
6dB LESS AT V
OUT
.
LT1252 • TA01
V
S
=
±5V
A
V
= 2
R
L
= 150Ω
V
O
= 1V
U
LT1252 • TA02
UO
UO
1
LT1252
ABSOLUTE
AXI U
RATI GS
Storage Temperature Range ................ – 65°C to 150°C
Junction Temperature (Note 2)............................ 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
Total Supply Voltage (V
+
to V
–
) ............................. 28V
Input Current .....................................................
±15mA
Output Short-Circuit Duration (Note 1) ........ Continuous
Operating Temperature Range .................... 0°C to 70°C
PACKAGE/ORDER I FOR ATIO
TOP VIEW
NC 1
– IN 2
+IN 3
V
–
4
8
7
6
5
NC
V
+
OUT
NC
ORDER PART
NUMBER
NC
1
2
3
4
LT1252CS8
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 150°C/ W
S8 PART MARKING
1252
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
+I
B
– I
B
A
VOL
PSRR
CMRR
V
OUT
I
OUT
I
S
R
IN
C
IN
PARAMETER
Input Offset Voltage
Noninverting Bias Current
Inverting Bias Current
Large-Signal Voltage Gain
Power Supply Rejection Ratio
Common-Mode Rejection Ratio
Maximum Output Voltage Swing
Maximum Output Current
Supply Current
Input Resistance
Input Capacitance
Power Supply Range
SR
Input Slew Rate
Output Slew Rate
Dual
Single
0°C
≤
T
A
≤
70°C, V
S
=
±5V
to
±12V,
unless otherwise noted.
MIN
TYP
5
1
20
MAX
15
15
100
UNITS
mV
µA
µA
V/V
dB
dB
V
V
mA
18
mA
MΩ
pF
±12
24
125
250
V
V
V/µs
V/µs
CONDITIONS
V
S
=
±5V,
V
O
=
±2V,
R
L
= 150Ω
V
S
=
±3V
to
±12V
V
S
=
±5V,
V
CM
=
±2V
V
S
=
±12V,
R
L
= 500Ω
V
S
=
±5V,
R
L
= 150Ω
A
V
= 1
A
V
= 2
2
U
U
W
W W
U
W
TOP VIEW
8
7
6
5
NC
V
+
OUT
NC
ORDER PART
NUMBER
LT1252CN8
–IN
+IN
V
–
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 150°C,
θ
JA
= 100°C/ W
560
60
55
±7.0
±2.5
30
1
±2
4
1500
70
65
±10.5
±3.7
55
8.5
10
3
LT1252
ELECTRICAL CHARACTERISTICS
0°C
≤
T
A
≤
70°C, V
S
=
±5V
to
±12V,
unless otherwise noted.
SYMBOL
t
r
t
p
PARAMETER
Small-Signal Rise Time
Rise and Fall Time
Propagation Delay
CONDITIONS
V
S
=
±12V,
A
V
= 2
V
S
=
±5V,
A
V
= 2, V
OUT
= 1V
P-P
V
S
=
±5V,
A
V
= 2
LT1252CN8: T
J
= T
A
+ (P
D
×
100°C/W)
LT1252CS8: T
J
= T
A
+ (P
D
×
150°C/W)
MIN
TYP
3.5
5.2
3.5
MAX
UNITS
ns
ns
ns
Note 1:
A heat sink may be required to keep the junction temperature
below absolute maximum when the output is shorted indefinitely.
Note 2:
T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
TYPICAL AC PERFOR A CE
BANDWIDTH
V
S
±12
±12
±12
±12
±12
±12
±12
±12
±12
±5
±5
±5
±5
±5
±5
±5
±5
±5
±5
A
V
1
–1
–1
2
2
5
5
10
10
1
1
–1
–1
2
2
5
5
10
10
R
L
150
1000
150
1000
150
1000
150
1000
150
1000
150
1000
150
1000
150
1000
150
1000
150
R
F
2370
1100
909
1210
909
1000
866
909
768
2210
1300
1000
732
909
787
825
698
750
619
R
G
None
1100
909
1210
909
249
215
100
84.5
None
None
1000
732
909
787
205
174
82.5
68.1
SMALL SIGNAL
– 3dB BW (MHz)
282
58
73
253
142
73
75
67
69
260
232
50
69
133
100
62
66
58
60
SMALL SIGNAL
– 0.1dB BW (MHz)
45
17
34
20
38
25
31
26
32
10
50
11
34
24
30
21
30
22
30
SMALL SIGNAL
PEAKING (dB)
1.9
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
2.4
0.8
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
NTSC VIDEO (Note 1)
V
S
±12
±12
±5
±5
A
V
2
2
2
2
R
L
1000
150
1000
150
R
F
1000
1000
1000
1000
R
G
1000
1000
1000
1000
DIFFERENTIAL
GAIN
0.02%
0.03%
0.02%
0.01%
DIFFERENTIAL
PHASE
0.02°
0.04°
0.08°
0.09°
Note 1:
Differential Gain and Phase are measured using a Tektronix TSG
120 YC/NTSC signal generator and a Tektronix 1780R Video Measurement
Set. The resolution of this equipment is 0.1% and 0.1°. Ten identical
U W
amplifier stages were cascaded giving an effective resolution of 0.01% and
0.01°.
3
LT1252
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
14
13
SUPPLY CURRENT (mA)
OUTPUT SATURATION VOLTAGE (V)
11
10
9
8
7
6
5
4
0
2
4
–55°C
COMMON-MODE RANGE (V)
12
25°C
125°C
175°C
6
8 10 12 14
SUPPLY VOLTAGE (±V)
Settling Time to 10mV
vs Output Step
10
8
6
NONINVERTING
INVERTING
V
S
= ±12V
R
F
= R
G
= 1k
–30
POWER SUPPLY REJECTION (dB)
DISTORTION (dBc)
OUTPUT STEP (V)
4
2
0
–2
–4
–6
–8
–10
0
20
60
40
SETTLING TIME (ns)
Spot Noise Voltage and Current
vs Frequency
100
100
–i
n
OUTPUT IMPEDANCE (Ω)
10
R
F
= R
G
= 2k
R
F
= R
G
= 1k
0.1
OUTPUT SHORT-CIRCUIT CURRENT (mA)
SPOT NOISE (nV/√Hz OR pA/√Hz)
10
e
n
+i
n
1
10
100
1k
10k
FREQUENCY (Hz)
4
U W
16
18
LT1252 • TPC01
Input Common-Mode Limit
vs Temperature
V
+
–0.5
–1.0
–1.5
–2.0
V
+
= 2V TO 12V
V
+
–0.5
–1.0
Output Saturation Voltage
vs Temperature
R
L
=
∞
±2V
≤
V
S
≤
±12V
2.0
1.5
1.0
0.5
V
–
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
V
–
= –2V TO –12V
1.0
0.5
V
–
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
LT1252 • TPC02
LT1252
• TPC03
2nd and 3rd Harmonic Distortion
vs Frequency
–20
V
S
= ±12V
V
O
= 2V
P-P
R
L
= 100Ω
R
F
= 820Ω
A
V
= 10dB
2ND
3RD
80
Power Supply Rejection
vs Frequency
V
S
= ±12V
R
L
= 100Ω
R
F
= R
G
= 1k
60
POSITIVE
NEGATIVE
40
–40
–50
–60
20
–70
80
100
1
10
FREQUENCY (MHz)
100
LT1252 • TPC05
0
10k
100k
1M
10M
FREQUENCY (Hz)
100M
LT1252 • TPC06
LT1252 • TPC04
Output Impedance
vs Frequency
70
V
S
= ±12V
Output Short-Circuit Current
vs Junction Temperature
60
1
50
40
0.01
100k
LT1252 • TPC07
0.001
10k
100k
1M
10M
FREQUENCY (Hz)
100M
30
–50 –25
0
25 50 75 100 125 150 175
TEMPERATURE (°C)
LT1252 • TPC09
LT1252 • TPC08
LT1252
TYPICAL PERFOR A CE CHARACTERISTICS
±12V
Frequency Response
5
4
3
2
PHASE
0
–20
–40
–60
GAIN (dB)
GAIN (dB)
1
0
–1
–2
–3
–4
–5
1M
V
S
= ±12V
A
V
= 1
R
L
= 150Ω
R
F
= 2.37k
10M
100M
FREQUENCY (Hz)
1G
LT1252 • TPC10
±12V
Frequency Response
12
11
10
9
PHASE
0
–20
–40
–60
GAIN (dB)
7
6
5
4
3
2
1M
V
S
= ±12V
A
V
= 2
R
L
= 150Ω
R
F
= 909Ω
R
G
= 909Ω
–100
–120
–140
–160
GAIN
–180
–200
10M
100M
FREQUENCY (Hz)
1G
LT1252 • TPC12
GAIN (dB)
8
±12V
Frequency Response
26
25
24
23
GAIN (dB)
GAIN (dB)
22
21
20
19
18
17
16
1M
V
S
= ±12V
A
V
= 10
R
L
= 150Ω
R
F
= 768Ω
R
G
= 84.5Ω
GAIN
10M
100M
FREQUENCY (Hz)
U W
±5V
Frequency Response
5
4
3
2
PHASE (DEG)
0
–20
–40
PHASE
–60
PHASE (DEG)
–80
GAIN
–100
–120
–140
–160
–180
–200
1
0
–1
–2
–3
–4
–5
1M
V
S
= ±5V
A
V
= 1
R
L
= 150Ω
R
F
= 1.3k
10M
100M
FREQUENCY (Hz)
1G
LT1252 • TPC11
–80
GAIN
–100
–120
–140
–160
–180
–200
±5V
Frequency Response
12
11
10
9
PHASE (DEG)
0
–20
–40
PHASE
–60
PHASE (DEG)
–80
8
7
6
5
4
3
2
1M
V
S
= ±5V
A
V
= 2
R
L
= 150Ω
R
F
= 787Ω
R
G
= 787Ω
GAIN
–80
–100
–120
–140
–160
–180
–200
10M
100M
FREQUENCY (Hz)
1G
LT1252 • TPC13
±5V
Frequency Response
0
–20
–40
26
25
24
23
PHASE (DEG)
22
21
20
19
18
17
16
1M
V
S
= ±5V
A
V
= 10
R
L
= 150Ω
R
F
= 619Ω
R
G
= 68.1Ω
GAIN
PHASE
0
–20
–40
–60
PHASE (DEG)
–80
–100
–120
–140
–160
–180
–200
10M
100M
FREQUENCY (Hz)
1G
LT1252 • TPC15
PHASE
–60
–80
–100
–120
–140
–160
–180
–200
1G
LT1252 • TPC14
5
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