LT1227
140MHz Video Current
Feedback Amplifier
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
140MHz Bandwidth: A
V
= 2, R
L
= 150Ω
1100V/µs Slew Rate
Low Cost
30mA Output Drive Current
0.01% Differential Gain
0.01° Differential Phase
High Input Impedance: 14MΩ, 3pF
Wide Supply Range:
±2V
to
±15V
Shutdown Mode: I
S
< 250µA
Low Supply Current: I
S
= 10mA
Inputs Common Mode to Within 1.5V of Supplies
Outputs Swing Within 0.8V of Supplies
The LT
®
1227 is a current feedback amplifier with wide
bandwidth and excellent video characteristics. The low
differential gain and phase, wide bandwidth, and 30mA
output drive current make the LT1227 well suited to drive
cables in video systems.
A shutdown feature switches the device into a high imped-
ance, low current mode, allowing multiple devices to be
connected in parallel and selected. Input to output isola-
tion in shutdown is 70dB at 10MHz for input amplitudes up
to 10V
P-P
. The shutdown pin interfaces to open collector
or open drain logic and takes only 4µs to enable or disable.
The LT1227 comes in the industry standard pinout and
can upgrade the performance of many older products. For
a dual or quad version, see the LT1229/1230 data sheet.
The LT1227 is manufactured on Linear Technology’s
proprietary complementary bipolar process.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
s
Video Amplifiers
Cable Drivers
RGB Amplifiers
Test Equipment Amplifiers
50Ω Buffers for Driving Mixers
TYPICAL APPLICATIO
Video Cable Driver
0.20
V
IN
Differential Gain and Phase
vs Supply Voltage
0.20
NTSC COMPOSITE
f = 3.58MHz
+
LT1227
75Ω
DIFFERENTIAL PHASE (DEG)
0.16
–
R
F
1k
75Ω
CABLE
V
OUT
0.12
0.08
∆φ
0.04
∆G
0
5
7
11
13
9
SUPPLY VOLTAGE (±V)
15
R
G
1k
V
OUT
=1
V
IN
75Ω
1227 TA01
U
0.16
U
U
DIFFERENTIAL GAIN (%)
0.12
0.08
0.04
0
LT1227 • TA02
1
LT1227
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
NULL 1
–IN 2
+IN 3
V
–
4
8 SHDN
7 V
+
6 OUT
5 NULL
Supply Voltage .....................................................
±18V
Input Current ......................................................
±15mA
Output Short Circuit Duration (Note 2) ........ Continuous
Operating Temperature Range
LT1227C .................................................. 0°C to 70°C
LT1227M
(OBSOLETE)
.................... – 55°C to 125°C
Storage Temperature Range ................. – 65°C to 150°C
Junction Temperature
Plastic Package ................................................ 150°C
Ceramic Package
(OBSOLETE)
........................ 175°C
Lead Temperature (Soldering, 10 sec.)................ 300°C
ORDER PART
NUMBER
LT1227CN8
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 150°C,
θ
JA
= 100°C/W (N)
J8 PACKAGE
8-LEAD CERAMIC DIP
T
JMAX
= 175°C,
θ
JA
= 100°C/W (J)
LT1227MJ8
OBSOLETE PACKAGE
Consider the N8 Package for Alternate Source.
TOP VIEW
NULL 1
–IN 2
+IN 3
V
–
4
8 SHDN
7 V
+
6
OUT
ORDER PART
NUMBER
LT1227CS8
S8 PART MARKING
1227
5 NULL
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 150°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CM
= 0,
±5V ≤
V
S
≤ ±15V,
pulse tested, unless otherwise noted.
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
Input Offset Voltage Drift
Noninverting Input Current
Inverting Input Current
Input Noise Voltage Density
Noninverting Input Noise Current Density
Inverting Input Noise Current Density
Input Resistance
Input Capacitance
Input Voltage Range
CONDITIONS
T
A
= 25°C
q
q
ELECTRICAL CHARACTERISTICS
MIN
TYP
±3
10
±0.3
±10
MAX
±10
±15
±3
±10
±60
±100
I
IN+
I
IN–
e
n
+i
n
–i
n
R
IN
C
IN
T
A
= 25°C
q
T
A
= 25°C
q
f = 1kHz, R
F
= 1k, R
G
= 10Ω, R
S
= 0Ω
f = 1kHz
f = 1kHz
V
IN
=
±13V,
V
S
=
±15V
V
IN
=
±3V,
V
S
=
±5V
V
S
=
±15V,
T
A
= 25°C
q
q
1.5
1.5
±13
±12
±3
±2
55
55
55
55
3.2
1.7
32
14
11
3
±13.5
±3.5
62
61
q
V
S
=
±5V,
T
A
= 25°C
q
CMRR
Common Mode Rejection Ratio
V
S
=
±15V,
V
CM
=
±13V,
T
A
= 25°C
V
S
=
±15V,
V
CM
=
±12V
V
S
=
±5V,
V
CM
=
±3V,
T
A
= 25°C
V
S
=
±5V,
V
CM
=
±2V
q
q
UNITS
mV
mV
µV/°C
µA
µA
µA
µA
nV/√Hz
pA/√Hz
pA/√Hz
MΩ
MΩ
pF
V
V
V
V
dB
dB
dB
dB
2
U
W
U
U
W W
W
LT1227
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
Inverting Input Current
Common Mode Rejection
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CM
= 0,
±5V ≤
V
S
≤ ±15V,
pulse tested, unless otherwise noted.
CONDITIONS
V
S
=
±15V,
V
CM
=
±13V,
T
A
= 25°C
V
S
=
±15V,
V
CM
=
±12V
V
S
=
±5V,
V
CM
=
±3V,
T
A
= 25°C
V
S
=
±5V,
V
CM
=
±2V
V
S
=
±2V
to
±15V,
T
A
= 25°C
V
S
=
±3V
to
±15V
V
S
=
±2V
to
±15V,
T
A
= 25°C
V
S
=
±3V
to
±15V
V
S
=
±2V
to
±15V,
T
A
= 25°C
V
S
=
±3V
to
±15V
V
S
=
±15V,
V
OUT
=
±10V,
R
L
= 1k
V
S
=
±5V,
V
OUT
=
±2V,
R
L
= 150Ω
V
S
=
±15V,
V
OUT
=
±10V,
R
L
= 1k
V
S
=
±5V,
V
OUT
=
±2V,
R
L
= 150Ω
V
S
=
±15V,
R
L
= 400Ω, T
A
= 25°C
V
S
=
±5V,
R
L
= 150Ω, T
A
= 25°C
q
MIN
q
TYP
3.5
4.5
q
q
q
MAX
10
10
10
10
PSRR
Power Supply Rejection Ratio
Noninverting Input Current
Power Supply Rejection
Inverting Input Current
Power Supply Rejection
Large-Signal Voltage Gain
Transresistance,
∆V
OUT
/∆I
IN–
Maximum Output Voltage Swing
60
60
80
2
0.25
50
50
5
5
q
q
q
q
q
q
A
V
R
OL
V
OUT
I
OUT
I
S
Maximum Output Current
Supply Current (Note 3)
Positive Supply Current, Shutdown
R
L
= 0Ω, T
A
= 25°C
V
S
=
±15V,
V
OUT
= 0V, T
A
= 25°C
q
55
55
100
100
±12
±10
±3
±2.5
30
72
72
270
240
±13.5
±3.7
60
10
120
V
S
=
±15V,
Pin 8 Voltage = 0V, T
A
= 25°C
q
I
8
SR
t
r
, t
f
BW
t
r
, t
f
t
S
Shutdown Pin Current (Note 4)
Output Leakage Current, Shutdown
Slew Rate (Notes 5 and 6)
Rise and Fall Time, V
OUT
= 1V
P-P
Small-Signal Bandwidth
Small-Signal Rise and Fall Time
Propagation Delay
Small-Signal Overshoot
Settling Time
Differential Gain (Note 7)
Differential Phase (Note 7)
V
S
=
±15V
V
S
=
±15V,
Pin 8 Voltage = 0V, T
A
= 25°C
T
A
= 25°C
V
S
=
±5V,
R
F
= 1k, R
G
= 1k, R
L
= 150Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 150Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 100Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 100Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 100Ω
0.1%, V
OUT
= 10V, R
F
= 1k, R
G
= 1k, R
L
= 1k
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 150Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 1k
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 150Ω
V
S
=
±15V,
R
F
= 1k, R
G
= 1k, R
L
= 1k
q
15.0
17.5
300
500
300
10
500
1100
8.7
140
3.3
3.4
5
50
0.014
0.010
0.010
0.013
UNITS
µA/V
µA/V
µA/V
µA/V
dB
dB
nA/V
nA/V
µA/V
µA/V
dB
dB
kΩ
kΩ
V
V
V
V
mA
mA
mA
µA
µA
µA
µA
V/µs
ns
MHz
ns
ns
%
ns
%
%
DEG
DEG
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
A heat sink may be required depending on the power supply
voltage.
Note 3:
The supply current of the LT1227 has a negative temperature
coefficient. For more information, see Typical Performance Characteristics
curves.
Note 4:
Ramp Pin 8 voltage down from 15V while measuring I
S
. When I
S
drops to less than 0.5mA, measure Pin 8 current.
Note 5:
Slew rate is measured at
±5V
on a
±10V
output signal while
operating on
±15V
supplies with R
F
= 2k, R
G
= 220Ω and R
L
= 400Ω.
Note 6:
AC parameters are 100% tested on the ceramic and plastic DIP
package parts (J and N suffix) and are sample tested on every lot of the SO
packaged parts (S suffix).
Note 7:
NTSC composite video with an output level of 2V.
3
LT1227
TYPICAL PERFOR A CE CHARACTERISTICS
Voltage Gain and Phase vs
Frequency, Gain = 6dB
10
9
8
PHASE
0
–3dB BANDWIDTH (MHz)
VOLTAGE GAIN (dB)
7
6
5
4
3
2
1
0
0.1
V
S
=
±15V
R
L
= 100Ω
R
F
= 910Ω
1
10
FREQUENCY (MHz)
100
LT1227 • TPC01
135
GAIN
180
225
120
100
80
60
40
20
0
R
F
= 500Ω
R
F
= 750Ω
R
F
= 1k
–3dB BANDWIDTH (MHz)
Voltage Gain and Phase vs
Frequency, Gain = 20dB
24
23
22
VOLTAGE GAIN (dB)
PHASE
21
20
19
18
17
16
15
14
0.1
V
S
=
±15V
R
L
= 100Ω
R
F
= 825Ω
1
10
FREQUENCY (MHz)
100
LT1227 • TPC04
135
GAIN
180
225
–3dB BANDWIDTH (MHz)
–3dB BANDWIDTH (MHz)
Voltage Gain and Phase vs
Frequency, Gain = 40dB
44
43
42
PHASE
0
–3dB BANDWIDTH (MHz)
VOLTAGE GAIN (dB)
41
40
39
38
37
36
35
34
0.1
V
S
=
±15V
R
L
= 100Ω
R
F
= 500Ω
1
10
FREQUENCY (MHz)
100
LT1227 • TPC07
135
GAIN
180
225
12
10
8
6
4
2
0
0
2
4
R
F
= 500Ω
R
F
= 1k
R
F
= 2k
–3dB BANDWIDTH (MHz)
4
U W
–3dB Bandwidth vs Supply
Voltage, Gain = 2, R
L
= 100Ω
180
160
140
PEAKING
≤
0.5dB
PEAKING
≤
5dB
PHASE SHIFT (DEG)
PHASE SHIFT (DEG)
PHASE SHIFT (DEG)
–3dB Bandwidth vs Supply
Voltage, Gain = 2, R
L
= 1k
180
160
140
120
100
80
60
40
20
16
0
18
0
2
4
6
8 10 12 14
SUPPLY VOLTAGE (±V)
16
18
R
F
= 1.5k
R
F
= 1k
PEAKING
≤
0.5dB
PEAKING
≤
5dB
R
F
= 750Ω
R
F
= 2k
45
90
R
F
= 2k
0
2
4
6
8 10 12 14
SUPPLY VOLTAGE (±V)
LT1227 • TPC02
LT1227 • TPC03
–3dB Bandwidth vs Supply
Voltage, Gain = 10, R
L
= 100Ω
0
45
90
180
160
140
120
100
80
60
40
20
0
0
2
4
6
8 10 12 14
SUPPLY VOLTAGE (±V)
16
18
R
F
= 2k
R
F
= 250Ω
R
F
= 500Ω
R
F
= 750Ω
R
F
= 1k
PEAKING
≤
0.5dB
PEAKING
≤
5dB
–3dB Bandwidth vs Supply
Voltage, Gain = 10, R
L
= 1k
180
160
140
120
100
80
60
40
20
0
0
2
4
6
8 10 12 14
SUPPLY VOLTAGE (±V)
16
18
R
F
= 2k
R
F
= 750Ω
R
F
= 1k
R
F
= 500Ω
PEAKING
≤
0.5dB
PEAKING
≤
5dB
LT1227 • TPC05
LT1227 • TPC06
–3dB Bandwidth vs Supply
Voltage, Gain = 100, R
L
= 100Ω
18
16
14
18
16
14
12
10
8
6
4
2
0
–3dB Bandwidth vs Supply
Voltage, Gain = 100, R
L
= 1k
R
F
= 500Ω
R
F
= 1k
45
90
R
F
= 2k
6
8 10 12 14
SUPPLY VOLTAGE (±V)
16
18
0
2
4
6
8 10 12 14
SUPPLY VOLTAGE (±V)
16
18
LT1227 • TPC08
LT1227 • TPC09
LT1227
TYPICAL PERFOR A CE CHARACTERISTICS
Maximum Capacitive Load
vs Feedback Resistor
10000
TOTAL HARMONIC DISTORTION (%)
R
L
= 1k
PEAKING
≤
5dB
GAIN = 2
CAPACITIVE LOAD (pF)
1000
0.1
V
S
=
±15V
R
L
= 400Ω
R
F
= R
G
= 1k
OUTPUT VOLTAGE (V
P-P
)
V
S
=
±5V
100
V
S
=
±15V
10
1
0
2
1
FEEDBACK RESISTOR (kΩ)
3
Input Common Mode Limit
vs Temperature
V
+
V
+
OUTPUT SATURATION VOLTAGE (V)
–0.5
COMMON MODE RANGE (V)
–1.0
–1.5
–2.0
V
+
= 2V TO 18V
–0.5
–1.0
OUTPUT SHORT-CIRCUIT CURRENT (mA)
2.0
1.5
1.0
0.5
V
–
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
V
–
= –2V TO –18V
Spot Noise Voltage and Current
vs Frequency
100
POWER SUPPLY REJECTION (dB)
SPOT NOISE (nV/√Hz OR pA/√Hz)
–i
n
POSITIVE
NEGATIVE
40
OUTPUT IMPEDANCE (Ω)
10
e
n
+i
n
1
10
100
1k
10k
FREQUENCY (Hz)
100k
LT1227 • TPC16
U W
LT1227 • TPC10
LT1227 • TPC13
Total Harmonic Distortion
vs Frequency
25
Maximum Undistorted Output
vs Frequency
V
S
=
±15V
R
L
= 1k
R
F
= 1k
A
V
= +10
A
V
= –1
A
V
= +1
A
V
= +2
20
15
0.01
V
O
= 7V
RMS
10
V
O
= 1V
RMS
5
0.001
10
0
100
1k
10k
FREQUENCY (Hz)
100k
LT1227 • TPC11
1
10
FREQUENCY (MHz)
100
LT1127 • TPC12
Output Saturation Voltage
vs Temperature
R
L
=
∞
±2V ≤
V
S
≤ ±18V
70
Output Short-Circuit Current
vs Junction Temperature
60
50
1.0
0.5
V
–
–50 –25
40
50
25
75
0
TEMPERATURE (°C)
100
125
30
–50 –25
0
25 50 75 100 125 150 175
TEMPERATURE (°C)
LT1227 • TPC15
LT1227
• TPC14
Power Supply Rejection
vs Frequency
80
V
S
=
±15V
R
L
= 100Ω
R
F
= R
G
= 1k
Output Impedance vs Frequency
100
V
S
=
±15V
60
10
R
F
= R
G
= 2k
R
F
= R
G
= 1k
0.1
1
20
0.01
0
10k
100k
1M
10M
FREQUENCY (Hz)
100M
LT1227 • TPC17
0.001
10k
100k
1M
10M
FREQUENCY (Hz)
100M
LT1227 • TPC18
5
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