LT1195
Low Power, High Speed
Operational Amplifier
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FEATURES
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DESCRIPTIO
The LT®1195 is a video operational amplifier optimized for
operation on single 5V and ±5V supplies. Unlike many
high speed amplifiers, the LT1195 features high openloop gain, over 75dB, and the ability to drive heavy loads
to a full power bandwidth of 8.5 MHz at 6VP-P. The LT1195
has a unity-gain stable bandwidth of 50MHz, a 60° phase
margin and consumes only 12mA of supply current,
making it extremely easy to use.
Gain-Bandwidth Product: 50MHz
Unity-Gain Stable
Slew Rate: 165V/µs
Output Current: ±20mA
Low Supply Current: 12mA
High Open-Loop Gain: 7.5V/mV
Low Cost
Single Supply 5V Operation
Industry Standard Pinout
Output Shutdown
Because the LT1195 is a true operational amplifier, it is an
ideal choice for wideband signal conditioning, fast
integrators, peak detectors, active filters, and applications
requiring speed, accuracy, and low cost.
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APPLICATIO S
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The LT1195 is a low power version of the popular LT1190,
and is available in 8-pin miniDIPs and SO packages with
standard pinouts. The normally unused Pin 5 is used for a
shutdown feature that shuts off the output and reduces
power dissipation to a mere 15mW.
Video Cable Drivers
Video Signal Processing
Fast Peak Detectors
Fast Integrators
Video Cable Drivers
Pulse Amplifiers
, LTC and LT are registered trademarks of Linear Technology Corporation
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TYPICAL APPLICATIO
Fast Pulse Detector
5V
RI
1k
VIN
RS
50Ω
Pulse Detector Response
3
CI
60pF
+
LT1195
2
–
D1
1N5712
7
6
RL
10k
4
CL
1000pF
OUTPUT
–5V
–5V
RB
10k
–5V
D2
1N5712
1195 TA01
INPUT
1195TAO2
1195fa
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LT1195
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AXI U
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ABSOLUTE
RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
Total Supply Voltage (V+ to V – ) ............................... 18V
Differential Input Voltage ......................................... ±6V
Input Voltage ........................................................... ±VS
Output Short-Circuit Duration (Note 2) ......... Continuous
Operating Temperature Range
LT1195M (OBSOLETE) ................... –55°C to 125°C
LT1195C ................................................ 0°C to 70°C
Junction Temperature (Note 3)
Plastic Package (CN8, CS8) ............................ 150°C
Ceramic Package (CJ8, MJ8) (OBSOLETE) ..... 175°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
BAL 1
8
BAL
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
S/D
LT1195CN8
LT1195CS8
S8 PART MARKING
S8 PACKAGE
N8 PACKAGE
8-LEAD PLASTIC SO
8-LEAD PDIP
TJMAX = 150°C, θJA = 100°C/ W (N8)
TJMAX = 150°C, θJA = 150°C/ W (S8)
1195
ORDER PART
NUMBER
J8 PACKAGE
8-LEAD CERDIP
LT1195MJ8
LT1195CJ8
TJMAX = 150°C, θJA = 100°C/ W (J8)
OBSOLETE PACKAGE
Consider the N8 or S8 Package for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
+
– 5V ELECTRICAL CHARACTERISTICS
V = ±5V, C ≤ 10pF, Pin 5 open circuit, unless otherwise noted.
S
L
SYMBOL
VOS
PARAMETER
Input Offset Voltage
IOS
IB
en
in
RIN
CMRR
PSRR
AVOL
Input Offset Current
Input Bias Current
Input Noise Voltage
Input Noise Current
Input Resistance Differential Mode
Common Mode
Input Capacitance
Input Voltage Range
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
VOUT
Output Voltage Swing
SR
FPBW
GBW
tr1, tf1
tr2, tf2
tPD
Slew Rate
Full Power Bandwidth
Gain-Bandwidth Product
Rise Time, Fall Time
Rise Time, Fall Time
Propagation Delay
Overshoot
Settling Time
Differential Gain
Differential Phase
CIN
tS
Diff AV
Diff Ph
TA = 25°C
CONDITIONS
J8, N8 Package
S8 Package
MIN
fO = 10kHz
fO = 10kHz
AV = 1
(Note 4)
VCM = –2.5 to 3.5V
VS = ±2.375V to ±8V
RL = 1k, VOUT = ±3V
RL = 150Ω, VOUT = ±3V
VS = ±8V, RL = 1k, VOUT = ±5V
VS = ±5V, RL = 1k
VS = ±8V, RL = 1k
AV = –1, RL = 1k (Note 5, 10)
VOUT = 6VP-P (Note 6)
AV = 50, VOUT = ±1.5V, 20% to 80% (Note 10)
AV = 1, VOUT = ±125mV, 10% to 90%
AV = 1, VOUT = ±125mV, 50% to 50%
AV = 1, VOUT = ±125mV
3V Step, 0.1% (Note 7)
RL = 150Ω, AV = 2 (Note 8)
RL = 150Ω, AV = 2 (Note 8)
LT1195M/C
TYP
3.0
3.0
0.2
±0.5
70
2
230
20
2.2
–2.5
60
60
2.0
0.5
±3.8
±6.7
110
125
MAX
8.0
10.0
1.0
±2.0
3.5
85
85
7.5
1.5
11.0
±4.0
±7.0
165
8.75
50
170
3.4
2.5
22
220
1.25
0.86
285
UNITS
mV
mV
µA
µA
nV√Hz
pA√Hz
kΩ
MΩ
pF
V
dB
dB
V/mV
V/mV
V/mV
V
V
V/µs
MHz
MHz
ns
ns
ns
%
ns
%
DEGP-P
1195fa
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LT1195
+
– 5V ELECTRICAL CHARACTERISTICS
TA = 25°C
VS = ±5V, CL ≤ 10pF, Pin 5 open circuit, unless otherwise noted.
SYMBOL
IS
IS/D
tON
tOFF
PARAMETER
Supply Current
Shutdown Supply Current
Shutdown Pin Current
Turn-On Time
Turn-Off Time
CONDITIONS
MIN
Pin 5 at V –
Pin 5 at V –
Pin 5 from V – to Ground, RL = 1k
Pin 5 from Ground to V –, RL = 1k
LT1195M/C
TYP
MAX
12
16
0.8
1.5
5
25
160
700
UNITS
mA
mA
µA
ns
ns
LT1195M/C
TYP
MAX
UNITS
5V ELECTRICAL CHARACTERISTICS
TA = 25°C
+
–
VS = 5V, VS , = OV, VCM = 2.5V, CL ≤ 10pF, Pin 5 open circuit, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
VOS
Input Offset Voltage
J8, N8 Package
S8 Package
IOS
Input Offset Current
IB
Input Bias Current
Input Voltage Range
(Note 4)
2.0
CMRR
AVOL
Common Mode Rejection Ratio
Large-Signal Voltage Gain
VCM = 2V to 3.5V
RL = 150Ω to Ground, VOUT = 1V to 3V
60
0.5
85
3.0
VOUT
Output Voltage Swing
RL = 150Ω to Ground
3.5
3.8
0.25
VOUT High
VOUT Low
9.0
11.0
1.0
mV
mV
µA
±0.5
±2.0
3.5
µA
V
dB
V/mV
0.4
Slew Rate
Gain-Bandwidth Product
IS
Supply Current
Shutdown Supply Current
Pin 5 at V –
11
0.8
15
1.5
mA
mA
Shutdown Pin Current
Pin 5 at V –
5
25
µA
MAX
15.0
UNITS
mV
µV/°C
µA
µA
dB
dB
V/mV
V/mV
V
mA
mA
µA
+
– 5V ELECTRICAL CHARACTERISTICS
140
45
V
V
SR
GBW
IS/D
AV = –1, VOUT = 1V to 3V
3.0
3.0
0.2
V/µs
MHz
–55°C ≤ TA ≤ 125°C, (Note 11)
VS = ±5V, Pin 5 open circuit, unless otherwise noted.
SYMBOL
VOS
∆VOS /∆T
IOS
IB
CMRR
PSRR
AVOL
PARAMETER
Input Offset Voltage
Input VOS Drift
Input Offset Current
Input Bias Current
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
VOUT
IS
Output Voltage Swing
Supply Current
Shutdown Supply Current
Shutdown Pin Current
IS/D
CONDITIONS
VCM = –2.5V to 3.5V
VS = ±2.375V to ±8V
RL = 1k, VOUT = ±3V
RL = 150Ω, VOUT = ±3V
RL = 1k
Pin 5 at V –, (Note 9)
Pin 5 at V –
MIN
55
55
1.50
0.25
±3.7
LT1195M
TYP
3.0
17
0.2
±0.5
85
80
5.0
0.8
±3.9
12
0.8
5
2.0
±2.5
18
2.5
25
1195fa
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LT1195
+
– 5V ELECTRICAL CHARACTERISTICS
0°C ≤ TA ≤ 70°C
VS = ±5V, Pin 5 open circuit, unless otherwise noted.
SYMBOL
VOS
PARAMETER
Input Offset Voltage
∆VOS /∆T
IOS
IB
CMRR
PSRR
AVOL
Input VOS Drift
Input Offset Current
Input Bias Current
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
VOUT
IS
Output Voltage Swing
Supply Current
Shutdown Supply Current
Shutdown Pin Current
IS/D
CONDITIONS
J8, N8 Package
S8 Package
MIN
VCM = –2.5V to 3.5V
VS = ±2.375V to ±5V
RL = 1k, VOUT = ±3V
RL = 150Ω, VOUT = ±3V
RL = 1k
60
60
2.0
0.3
±3.7
Pin 5 at V – (Note 9)
Pin 5 at V –
5V ELECTRICAL CHARACTERISTICS
LT1195C
TYP
3.0
3.0
12
0.2
±0.5
85
90
7.5
1.5
±3.9
12
0.9
5
MAX
10.0
15.0
17
2.0
25
UNITS
mV
mV
µV/°C
µA
µA
dB
dB
V/mV
V/mV
V
mA
mA
µA
MAX
UNITS
10.0
15.0
mV
mV
µV/°C
µA
µA
V
dB
V
V
mA
mA
µA
1.7
±2.5
0°C ≤ TA ≤ 70°C
VS+ = 5V, VS– = OV, Pin 5 open circuit, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
VOS
Input Offset Voltage
J8, N8 Package
S8 Package
∆VOS /∆T
IOS
IB
Input VOS Drift
Input Offset Current
Input Bias Current
Input Voltage Range
Common Mode Rejection Ratio
Output Voltage Swing
CMRR
VOUT
IS
IS/D
Supply Current
Shutdown Supply Current
Shutdown Pin Current
(Note 4)
VCM = 2V to 3.5V
RL = 150Ω to Ground
Pin 5 at V – (Note 9)
Pin 5 at V –
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 to keep the junction temperature
below absolute maximum when the output is shorted continuously.
Note 3: TJ is calculated from the ambient temperature TA and power
dissipation PD according to the following formats:
LT1195MJ8/LT1195CJ8: TJ = TA + (PD • 100°C/ W)
LT1195N:
TJ = TA + (PD • 100°C/ W)
LT1195CS:
TJ = TA + (PD • 150°C/ W)
Note 4: Exceeding the input common mode range may cause the output
to invert.
Note 5: Slew rate is measured between ±1V on the output, with ±3V input
step.
MIN
LT1195C
TYP
1.0
1.0
15
0.2
±0.5
VOUT High
VOUT Low
2.0
60
3.5
85
3.75
0.15
12
0.9
5
1.7
±2.5
3.5
0.4
16
2.0
25
Note 6: Full power bandwidth is calculated from the slew rate
measurement: FPBW = SR/2πVP.
Note 7: Settling time measurement techniques are shown in “Take the
Guesswork Out of Settling Time Measurements,” EDN, September 19, 1985.
Note 8: NTSC (3.58MHz). For RL = 1k, Diff AV = 0.3%, Diff Ph = 0.35°.
Note 9: See Applications Information section for shutdown at elevated
temperatures. Do not operate the shutdown above TJ > 125°C.
Note 10: AC parameters are 100% tested on the ceramic and plastic DIP
packaged parts (J8 and N8 suffix) and are sample tested on every lot of
the SO packaged parts (S8 suffix).
Note 11: Do not operate at AV < 2 for TA < 0°C.
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LT1195
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Bias Current vs
Common Mode Voltage
3.0
V+
100
VS = ±5V
VS = ±5V
–0.5
2.0
1.5
1.0
–55°C
0.5
25°C
0
+IB
0
COMMON MODE RANGE (V)
INPUT BIAS CURRENT (nA)
2.5
–100
–IB
–200
IOS
–300
125°C
–5 –4 –3 –2 –1 0 1 2 3
COMMON MODE VOLTAGE (V)
4
5
–400
–50
0
25
75
50
TEMPERATURE (°C)
–25
400
300
200
100
0
1k
10k
FREQUENCY (Hz)
8
6
2
10
100
1k
10k
FREQUENCY (Hz)
0
25
75
50
TEMPERATURE (°C)
125°C
10
100
125
1195 G07
0
2
8
4
6
±SUPPLY VOLTAGE (V)
1195 G06
TA = –55°C
VS = ±5V
VO = ±3V
1
–1
TA = 25°C
TA = 125°C
10
6k
4k
2k
RL = 150Ω
TA = –55°C
100
LOAD RESISTANCE (Ω)
RL = 1k
8k
TA = 25°C
TA = 125°C
–3
10
Open-Loop Gain vs Temperature
–5
–25
12
8
100k
3
VS/D = –VEE
0
–50
25°C
10k
VS = ±5V
OUTPUT VOLTAGE SWING (V)
SHUTDOWN SUPPLY CURRENT (mA)
1
125
–55°C
1195 G05
VS/D = –VEE + 0.6V
2
100
4
5
VS/D = –VEE + 0.2V
0
25
50
75
TEMPERATURE (°C)
14
Output Voltage Swing vs
Load Resistance
VS/D = –VEE + 0.4V
–25
VS = ±5V
TA = 25°C
RS = 100k
10
100k
6
3
V + = –1.8V TO –9V
1.0
16
12
Shutdown Supply Current
vs Temperature
4
1.5
Supply Current vs Supply Voltage
14
1195 G04
5
2.0
1195 G03
SUPPLY CURRENT (mA)
EQUIVALENT INPUT NOISE CURRENT (pA/√Hz)
EQUIVALENT INPUT NOISE VOLTAGE (nV/√Hz)
VS = ±5V
TA = 25°C
RS = 0Ω
VS = ±5V
–2.0
Equivalent Input Noise Current
vs Frequency
600
100
–1.5
1195 G02
Equivalent Input Noise Voltage
vs Frequency
10
V + = 1.8V TO 9V
V–
–50
125
100
1195 G01
500
–1.0
0.5
–0.5
OPEN-LOOP GAIN (V/V)
INPUT BIAS CURRENT (µA)
Common Mode Voltage vs
Temperature
Input Bias Current vs
Temperature
1k
1195 G08
0
–50
–25
0
25
75
50
TEMPERATURE (°C)
100
125
1195 G09
1195fa
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LT1195
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TYPICAL PERFOR A CE CHARACTERISTICS
100
20k
60
VOLTAGE GAIN (dB)
40
GAIN
20
20
VS = ±5V
TA = 25°C
RL = 1k
0
PHASE MARGIN (DEG)
60
60
0
OPEN-LOOP VOLTAGE GAIN (V/V)
80
80
–20
–20
100k
1M
10M
FREQUENCY (Hz)
16k
12k
8k
4k
0
100
100M
AV = 20dB
VS = ±5V
VO = ±3V
TA = 25°C
PHASE
GAIN-BANDWIDTH PRODUCT (MHz)
100
40
Gain-Bandwidth Product vs
Supply Voltage
Open-Loop Voltage Gain vs
Load Resistance
Gain and Phase vs Frequency
1k
LOAD RESISTANCE (Ω)
70
60
60
50
50
40
40
30
30
–50 –25
50
25
75
0
TEMPERATURE (°C)
20
125
100
AV = 10
1
AV = 1
0.1
0.01
1k
10k
1M
100k
FREQUENCY (Hz)
0
–20
1k
10k
100k
1M
FREQUENCY (Hz)
10M
100M
1195 G16
20
10
V+
–0.7
VS = ±5V
OUTPUT SATURATION VOLTAGE (V)
20
OUTPUT SHORT-CIRCUIT CURRENT (mA)
POWER SUPPLY REJECTION RATIO (dB)
+PSRR
–PSRR
30
1M
10M
FREQUENCY (Hz)
100M
1195 G15
36
VS = ±5V
TA = 25°C
VRIPPLE = ±300mV
40
0
100k
100M
10M
Output Short-Circuit Current
vs Temperature
80
10
VS = ±5V
TA = 25°C
RL = 1k
50
1195 G14
Power Supply Rejection Ratio
vs Frequency
40
8
4
6
±SUPPLY VOLTAGE (V)
Common Mode Rejection Ratio
vs Frequency
10
1195 G13
60
2
1195 G12
COMMON MODE REJECTION RATIO (dB)
70
0
60
80
UNITY-GAIN
PHASE MARGIN
20
VS = ±5V
TA = 25°C
OUTPUT IMPEDANCE (Ω)
80
30
100
PHASE MARGIN (DEG)
UNITY-GAIN FREQUENCY (MHz)
90
40
Output Impedance vs Frequency
90
VS = ±5V
RL = 1k
TA = 125°C
1195 G11
Unity-Gain Frequency and Phase
Margin vs Temperature
UNITY-GAIN
FREQUENCY
TA = 25°C
50
10k
1195 G10
100
TA = –55°C
35
34
33
32
31
30
–50
–25
50
0
25
75
TEMPERATURE (°C)
100
125
1195 G17
±Output Swing vs Supply Voltage
–0.8
125°C
–0.9
25°C
–1.0
–55°C
–1.1
0.5
RL = RFB
±1.8V ≤ VS ≤ ±9V
0.4
125°C
25°C
0.3
–55°C
0.2
0.1
V– 0
2
6
4
SUPPLY VOLTAGE (V)
8
10
1195 G18
1195fa
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LT1195
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TYPICAL PERFOR A CE CHARACTERISTICS
Output Voltage Step vs
Settling Time, AV = –1
Slew Rate vs Temperature
4
OUTPUT VOLTAGE STEP (V)
SLEW RATE (V/µs)
VS = ±5V
RFB = 1k
VO = ±2V
AV = –1
–SLEW RATE
200
+SLEW RATE
4
VS = ±5V
TA = 25°C
RL = 1k
2
10mV
OUTPUT VOLTAGE STEP (V)
250
150
–50
Output Voltage Step vs
Settling Time, AV = 1
1mV
0
–2
10mV
1mV
–4
–25
50
0
25
75
TEMPERATURE (°C)
100
125
VS = ±5V
TA = 25°C
RL = 1k
2
10mV
1mV
0
10mV
1mV
–2
–4
200
100
300
SETTLING TIME (ns)
0
400
200
100
300
SETTLING TIME (ns)
0
400
1195 G20
1195 G19
Large-Signal Transient Response
1195 G21
Large-Signal Transient Response
AV = 1, RL = 1k
AV = –1, RL = 1k
1195 G23
1195 G22
Overload Recovery
5V
3
+
7
LT1195
2
–
6
4
8
1
INPUT OFFSET VOLTAGE CAN BE ADJUSTED OVER A
±150mV RANGE WITH A 1k to 10k POTENTIOMETER.
1195 G25
AV = 1, VIN = 11VP-P
1195 G24
1195fa
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LT1195
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APPLICATIO S I FOR ATIO
Power Supply Bypassing
The LT1195 is quite tolerant of power supply bypassing.
In some applications a 0.1µF ceramic disc capacitor
placed 0.5 inches from the ampifier is all that is required.
In applications requiring good settling time, it is important
to use multiple bypass capacitors. A 0.1µF ceramic disc in
parallel with a 4.7µF tantalum is recommended.
Cable Terminations
The LT1195 operational amplifier has been optimized as a
low cost video cable driver. The ±20mA guaranteed output
current enables the LT1195 to easily deliver 6VP-P into
150Ω, while operating on ±5V supplies.
Double-Terminated Cable Driver
5V
3
7
+
LT1195
2
–
RG
4
75Ω
6
RFB
CABLE
75Ω
–5V
1195 AI01
Cable Driver Voltage Gain vs Frequency
8
receiving end (75Ω to ground) to absorb unwanted energy. The best performance can be obtained by double
termination (75Ω in series with the output of the amplifier,
and 75Ω to ground at the other end of the cable). This
termination is preferred because reflected energy is absorbed at each end of the cable. When using the double
termination technique it is important to note that the signal
is attenuated by a factor of 2, or 6dB. This can be compensated for by taking a gain of 2, or 6dB in the amplifier.
Using the Shutdown Feature
The LT1195 has a unique feature that allows the amplifier
to be shut down for conserving power, or for multiplexing
several amplifiers onto a common cable. The amplifier will
shutdown by taking Pin 5 to V –. In shutdown, the amplifier
dissipates 15mW while maintaining a true high impedance
output state of 15k in parallel with the feedback resistors.
The amplifiers must be used in a noninverting configuration for MUX applications. In inverting configurations the
input signal is fed to the output through the feedback
components. The following scope photos show that with
very high RL, the output is truly high impedance; the
output slowly decays toward ground. Additionally, when
the output is loaded with as little as 1k the amplifier shuts
off in 700ns. This shutoff can be under the control of HC
CMOS operating between 0V and –5V.
6
VOLTAGE GAIN (dB)
4
AV = 2
RFB = 1k
RG = 330Ω
2
0
Output Shutdown
AV = 1
RFB = 1k
RG = 1k
–2
–4
–6
–8
–10
VS = ±5V
TA = 25°C
–12
100k
1M
10M
FREQUENCY (Hz)
100M
1195 AI02
When driving a cable it is important to terminate the cable
to avoid unwanted reflections. This can be done in one of
two ways: single termination or double termination. With
single termination, the cable must be terminated at the
1MHz SINE WAVE GATED OFF WITH SHUTDOWN PIN
AV = 1, RL = SCOPE PROBE
1195 AI03
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LT1195
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APPLICATIO S I FOR ATIO
Output Shutdown
Single 5V Video Amplifier
VIN
10µF
5V
1k
3
+
5V
7
LT1195
R1
3k
2
RG
1k
–
4
1000µF
6
75Ω
RFB
1k
10k
R2
2k
100µF
75Ω
1195 AI05
1MHz SINE WAVE GATED OFF WITH SHUTDOWN PIN
AV = 1, RL = 1k
1195 AI04
Video Multiburst at Pin 6 of Amplifier
Detecting Pulses
The front page shows a circuit for detecting very fast
pulses. In this open-loop design, the detector diode is D1
and a level shifting or compensating diode is D2. A load
resistor RL is connected to –5V, and an identical bias
resistor RB is used to bias the compensating diode. Equal
value resistors ensure that the diode drops are equal. A
very fast pulse will exceed the amplifier slew rate and
cause a long overload recovery time. Some amount of
dV/dt limiting on the input can help this overload condition, however too much will delay the response. Also
shown is the response to a 4VP-P input that is 150ns wide.
The maximum output slew rate in the photo is 30V/µs. This
rate is set by the 30mA current limit driving 1000pF.
3V
2V
1V
0V
1195 AI06
Vector Plot of Standard Color Burst
Operation on Single 5V Supply
The LT1195 has been optimized for a single 5V supply.
This circuit amplifies standard composite video (1VP-P
including sync) by 2 and drives a double-terminated 75Ω
cable. Resistors R1 and R2 bias the amplifier at 2V,
allowing the sync pulses to stay within the common mode
range of the amplifier. Large coupling capacitors are
required to pass the low frequency sidebands of the
composite signal. A multiburst response and vector plot
standard color burst are shown.
1195 AI07
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9
LT1195
U
W
U U
APPLICATIO S I FOR ATIO
1.5MHz Square Wave Input and Equalized
Response Through 1000 Feet of Twisted-Pair
Send Color Video Over Twisted-Pair
With an LT1195 it is possible to send and receive color
composite video signals more than 1000 feet on a low cost
twisted-pair. A bidirectional “video bus” consists of the
LT1195 op amp and the LT1187 video difference amplifier.
A pair of LT1195s at TRANSMIT 1, is used to generate
differential signals to drive the line which is back-terminated in its characteristic impedance. The LT1187
twisted-pair receiver, converts signals from differential to
single-ended. Topology of the LT1187 provides for cable
compensation at the amplifier’s feedback node as shown.
In this case, 1000 feet of twisted-pair is compensated with
1000pF and 50Ω to boost the 3dB bandwidth of the
system from 750kHz to 4MHz. This bandwidth is adequate
to pass a 3.58MHz chrome subcarrier and the 4.5MHz
sound subcarrier. Attenuation in the cable can be compensated by lowering the gain set resistor RG. At TRANSMIT
2, another pair of LT1195s serve the dual function to
provide cable termination via low output impedance and
generate differential signals for TRANSMIT 2. Cable termination is made up of 15Ω and 33Ω attentuators to reduce
the differential input signal to the LT1187. Maximum input
signal for the LT1187 is 760mVP-P.
1195 A109
Multiburst Pattern Passed Through
1000 Feet of Twisted-Pair
1.5MHz Square Wave Input and Unequalized
Response Through 1000 Feet of Twisted-Pair
1195 A110
Vector Plot of Standard Color Burst Through
1000 Feet of Twisted-Pair
1195 A108
1195 A111
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10
LT1195
U
W
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APPLICATIO S I FOR ATIO
Bidirectional Video Bus
TRANSMIT 1
3
+
1k
2
75Ω
TRANSMIT 2
6
LT1195
6
–
1k
1k
–
–
6
6
LT1195
+
33Ω
S/D
75Ω
6
75Ω
2
1k
1k
1k
3
1k
LT1195
–
1k
2
3
+
+
5
–
LT1187
+
RFB
–
33Ω
15Ω
3
1000 FT
TWISTED-PAIR
15Ω
15Ω
15Ω
2
33Ω
LT1195
3
S/D
3
2
1
8
8
+
–
+
–
300Ω
1000pF
+
33Ω
1
RG
300Ω
2
5
LT1187
6
75Ω
RFB
300Ω
1000pF
50Ω
50Ω
RG
300Ω
RECEIVE 1
RECEIVE 2
1195 AI12
W
W
SIWPLIFIED SCHEWATIC
7 V+
VBIAS
VBIAS
CM
+ 3
CFF
– 2
V+
V+
6 VOUT
*
4 V–
5
1
8
S/D
BAL
BAL
1195 SS
* SUBSTRATE DIODE, DO NOT FORWARD BIAS
1195fa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LT1195
U
PACKAGE DESCRIPTIO
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
.300 BSC
(7.62 BSC)
CORNER LEADS OPTION
(4 PLCS)
.008 – .018
(0.203 – 0.457)
0° – 15°
.015 – .060
(0.381 – 1.524)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.405
(10.287)
MAX
.005
(0.127)
MIN
.200
(5.080)
MAX
8
NOTE: LEAD DIMENSIONS APPLY TO SOLDER
DIP/PLATE OR TIN PLATE LEADS
.014 – .026
(0.360 – 0.660)
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.045 – .065
(1.143 – 1.651)
6
7
2
3
4
.125
3.175
MIN
.100
(2.54)
BSC
J8 0801
OBSOLETE PACKAGE
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
.009 – .015
(0.229 – 0.381)
(
+.035
.325 –.015
+0.889
8.255
–0.381
.130 ± .005
(3.302 ± 0.127)
.045 – .065
(1.143 – 1.651)
.400*
(10.160)
MAX
.065
(1.651)
TYP
7
6
5
1
2
3
4
.255 ± .015*
(6.477 ± 0.381)
.125
(3.175) .020
MIN
(0.508)
MIN
.018 ± .003
(0.457 ± 0.076)
.100
(2.54)
BSC
)
8
N8 0502
NOTE:
1. DIMENSIONS ARE
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
.050 BSC
N
8
.245
MIN
2
3
N/2
6
5
N
.160 ±.005
1
7
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
N/2
.030 ±.005
TYP RECOMMENDED SOLDER PAD LAYOUT
NOTE:
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE
MOLD FLASH OR PROTRUSIONS.
.010 – .020
× 45°
MOLD FLASH OR PROTRUSIONS SHALL
(0.254 – 0.508)
NOT EXCEED .006" (0.15mm)
.008 – .010
0°– 8° TYP
(0.203 – 0.254)
.016 – .050
(0.406 – 1.270)
1
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
2
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
SO8 0502
1195fa
12
Linear Technology Corporation
LW/TP 1002 1K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 1993
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