LT1195MJ8 [Linear]
Low Power, High Speed Operational Amplifier; 低功耗，高速运算放大器
| 型号： | LT1195MJ8 |
| 厂家： | 
Linear |
| 描述： | Low Power, High Speed Operational Amplifier |
| 文件： | 总12页 (文件大小：396K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT1195
Low Power, High Speed
Operational Amplifier
U
DESCRIPTIO
EATURE
S
F
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Gain-Bandwidth Product
Unity-Gain Stable
Slew Rate
50MHz
TheLTC1195isavideooperationalamplifieroptimizedfor
operation on single 5V and ±5V supply. Unlike many high
speed amplifiers, the LT1195 features high open-loop
gain,over75dB,andtheabilitytodriveheavyloadstoafull
power bandwidth of 8.5 MHz at 6VP-P. The LT1195 has a
unity-gain stable bandwidth of 50MHz, and a 60° phase
margin, and consumes only 12mA of supply current,
making it extremely easy to use.
165V/µs
±20mA
12mA
Output Current
Low Supply Current
High Open-Loop Gain
Low Cost
Single Supply 5V Operation
Industry Standard Pinout
Output Shutdown
7.5V/mV
Because the LT1195 is a true operational amplifier, it is an
ideal choice for wideband signal conditioning, fast inte-
grators, peak detectors, active filters, and applications
requiring speed, accuracy, and low cost.
O U
PPLICATI
S
A
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.
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Video Cable Drivers
Video Signal Processing
Fast Peak Detectors
Fast Integrators
Video Cable Drivers
Pulse Amplifiers
U
O
TYPICAL APPLICATI
Fast Pulse Detector
Pulse Detector Response
5V
R
I
1k
D1
3
2
7
+
–
1N5712
6
C
R
I
S
V
IN
LT1195
60pF
50Ω
OUTPUT
C
L
1000pF
R
L
4
10k
–5V
–5V
D2
1N5712
R
B
10k
INPUT
–5V
1195 TA01
1195TAO2
1
LT1195
W
U
W W W
U
/O
TOP VIEW
PACKAGE RDER I FOR ATIO
ABSOLUTE AXI U RATI GS
Total Supply Voltage (V+ to V–) ............................... 18V
Differential Input Voltage ......................................... ±6V
Input Voltage ........................................................... ±VS
Output Short-Circuit Duration (Note 1).........Continuous
Operating Temperature Range
ORDER PART
NUMBER
BAL
–IN
+IN
1
2
3
4
BAL
8
7
6
5
+
V
LT1195MJ8
LT1195CJ8
LT1195CN8
LT1195CS8
OUT
S/D
–
V
LT1195M ........................................ –55°C to 125°C
LT1195C ................................................ 0°C to 70°C
Junction Temperature (Note 2)
Plastic Package (CN8, CS8) ............................ 150°C
Ceramic Package (CJ8, MJ8).......................... 175°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
J8 PACKAGE
N8 PACKAGE
8-LEAD CERAMIC DIP 8-LEAD PLASTIC DIP
S8 PACKAGE
8-LEAD PLASTIC SOIC
S8 PART MARKING
1195
TJMAX = 175°C, θJA = 100°C/ W (J8)
T
JMAX = 150°C, θJA = 100°C/ W (N8)
TJMAX = 150°C, θJA = 150°C/ W (S8)
+
±5V ELECTRICAL CHARACTERISTICS
TA = 25°C
–
VS = ±5V, CL ≤ 10pF, pin 5 open circuit, unless otherwise noted.
LT1195M/C
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
Input Offset Voltage
J8, N8 Package
S8 Package
3.0
3.0
8.0
10.0
mV
mV
OS
I
I
e
Input Offset Current
Input Bias Current
Input Noise Voltage
Input Noise Current
0.2
±0.5
70
1.0
±2.0
µA
µA
nV√Hz
pA√Hz
OS
B
f
f
= 10kHz
= 10kHz
n
O
O
i
2.0
n
R
Input Resistance Differential Mode
Common Mode
230
20
kΩ
MΩ
IN
C
Input Capacitance
Input Voltage Range
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
A = 1
(Note 3)
2.2
pF
V
dB
dB
V/mV
V/mV
V/mV
IN
V
–2.5
60
60
2.0
0.5
3.5
CMRR
PSRR
A
V
= –2.5 to 3.5V
85
85
7.5
1.5
CM
V = ±2.375V to ±8V
S
R = 1k, V = ±3V
OUT
VOL
L
R = 150Ω, V
= ±3V
L
OUT
V = ±8V, R = 1k, V = ±5V
S
11.0
L
OUT
V
Output Voltage Swing
V = ±5V, R = 1k
±3.8
±6.7
±4.0
±7.0
V
V
OUT
S
L
V = ±8V, R = 1k
S
L
SR
FPBW
GBW
Slew Rate
A = –1, R = 1k, (Note 4, 9)
110
165
8.75
50
170
3.4
V/µs
MHz
MHz
ns
ns
ns
V
L
Full Power Bandwidth
Gain-Bandwidth Product
Rise Time, Fall Time
Rise Time, Fall Time
Propagation Delay
Overshoot
V
= 6V
,
(Note 5)
OUT
P-P
t , t
A = 50, V = ±1.5V, 20% to 80%, (Note 9)
OUT
125
250
r1 f1
V
t , t
A = 1, V
= ±125mV, 10% to 90%
= ±125mV, 50% to 50%
= ±125mV
r2 f2
V
OUT
OUT
OUT
t
A = 1, V
2.5
22
PD
V
A = 1, V
V
%
t
Settling Time
Differential Gain
Differential Phase
3V Step, 0.1%, (Note 6)
R = 150Ω, A = 2, (Note 7)
220
1.25
0.86
ns
%
DEG
P-P
S
Diff A
Diff Ph
V
L
V
R = 150Ω, A = 2, (Note 7)
L
V
2
LT1195
+
±5V ELECTRICAL CHARACTERISTICS TA = 25°C
–
VS = ±5V, CL ≤ 10pF, pin 5 open circuit, unless otherwise noted.
LT1195M/C
TYP
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
mA
mA
µA
I
Supply Current
12
0.8
5
160
700
16
1.5
25
S
–
Shutdown Supply Current
Shutdown Pin Current
Turn-On Time
Pin 5 at V
Pin 5 at V
–
I
t
t
S/D
ON
–
Pin 5 from V to Ground, R = 1k
ns
ns
L
–
Turn-Off Time
Pin 5 from Ground to V , R = 1k
OFF
L
5V ELECTRICAL CHARACTERISTICS TA = 25°C
VS+ = 5V, VS–, = OV, VCM = 2.5V, CL ≤ 10pF, pin 5 open circuit, unless otherwise noted.
LT1195M/C
TYP
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
V
Input Offset Voltage
J8, N8 Package
S8 Package
3.0
3.0
9.0
11.0
mV
mV
OS
I
I
Input Offset Current
0.2
1.0
±2.0
3.5
µA
µA
OS
Input Bias Current
±0.5
B
Input Voltage Range
(Note 3)
2.0
60
V
CMRR
Common-Mode Rejection Ratio
Large-Signal Voltage Gain
Output Voltage Swing
V
= 2V to 3.5V
85
3.0
3.8
0.25
140
45
dB
CM
A
V
R = 150Ω to Ground, V = 1V to 3V
OUT
0.5
3.5
V/mV
V
VOL
OUT
L
R = 150Ω to Ground
L
V
High
Low
OUT
V
0.4
V
OUT
SR
Slew Rate
A = –1, V
V
= 1V to 3V
OUT
V/µs
MHz
mA
mA
µA
GBW
Gain-Bandwidth Product
Supply Current
I
I
11
15
1.5
25
S
–
–
Shutdown Supply Current
Shutdown Pin Current
Pin 5 at V
Pin 5 at V
0.8
5
S/D
+
±5V ELECTRICAL CHARACTERISTICS –55°C ≤ TA ≤ 125°C, (Note 10)
–
VS = ±5V, pin 5 open circuit, unless otherwise noted.
LT1195M
TYP
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
mV
µV/°C
µA
µA
dB
dB
V/mV
V/mV
V
Input Offset Voltage
3.0
17
0.2
±0.5
85
80
5.0
0.8
15.0
OS
∆V /∆T
Input V Drift
OS
OS
I
I
Input Offset Current
Input Bias Current
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
2.0
±2.5
OS
B
CMRR
PSRR
V
= –2.5V to 3.5V
55
55
1.50
0.25
CM
V = ±2.375V to ±8V
S
A
R = 1k, V = ±3V
OUT
VOL
L
R = 150Ω, V
L
= ±3V
OUT
V
Output Voltage Swing
Supply Current
Shutdown Supply Current
Shutdown Pin Current
R = 1k
±3.7
±3.9
12
0.8
5
V
mA
mA
µA
OUT
L
I
I
18
2.5
25
S
–
Pin 5 at V , (Note 8)
Pin 5 at V
–
S/D
3
LT1195
+
5V
ELECTRICAL CHARACTERISTICS
0°C ≤ TA ≤ 70°C
–
VS = ±5V, pin 5 open circuit, unless otherwise noted.
LT1195C
TYP
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
V
Input Offset Voltage
J8, N8 Package
S8 Package
3.0
3.0
10.0
15.0
mV
mV
OS
∆V /∆T
Input V Drift
Input Offset Current
Input Bias Current
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
12
0.2
±0.5
85
90
7.5
1.5
µV/°C
µA
OS
OS
I
I
1.7
±2.5
OS
B
µA
dB
dB
V/mV
V/mV
CMRR
PSRR
V
= –2.5V to 3.5V
60
60
2.0
0.3
CM
V = ±2.375V to ±5V
R = 1k, V = ±3V
R = 150Ω, V
S
A
VOL
L
OUT
= ±3V
OUT
L
V
Output Voltage Swing
Supply Current
Shutdown Supply Current
Shutdown Pin Current
R = 1k
±3.7
±3.9
12
0.9
5
V
mA
mA
µA
OUT
L
I
I
17
2.0
25
S
–,
Pin 5 at V (Note 8)
Pin 5 at V
–
S/D
0°C ≤ TA ≤ 70°C
5V ELECTRICAL CHARACTERISTICS
VS+ = 5V, VS– = OV, VCM = 2.5V, pin 5 open circuit, unless otherwise noted.
LT1195C
TYP
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
V
Input Offset Voltage
J8, N8 Package
S8 Package
1.0
1.0
10.0
15.0
mV
mV
OS
∆V /∆T
Input V Drift
15
0.2
µV/°C
µA
µA
V
OS
OS
I
I
Input Offset Current
1.7
±2.5
3.5
OS
B
Input Bias Current
±0.5
Input Voltage Range
Common-Mode Rejection Ratio
Output Voltage Swing
(Note 3)
2.0
60
3.5
CMRR
V
CM
= 2V to 3.5V
85
3.75
0.15
12
0.9
5
dB
V
V
R = 150Ω to Ground
L
V
V
High
Low
OUT
OUT
0.4
16
2.0
25
V
OUT
I
I
Supply Current
Shutdown Supply Current
Shutdown Pin Current
mA
mA
µA
S
–
Pin 5 at V , (Note 8)
–
Pin 5 at V
S/D
Note 1: A heat sink may be required to keep the junction temperature
below absolute maximum when the output is shorted continuously.
Note 6: Settling time measurement techniques are shown in “Take the
Guesswork Out of Settling Time Measurements,” EDN, September 19, 1985.
Note 2: T is calculated from the ambient temperature T and power
Note 7: NTSC (3.58MHz). For R = 1k, Diff A = 0.3%, Diff Ph = 0.35°.
L V
J
A
dissipation P according to the following formats:
D
Note 8: See Applications Information section for shutdown at elevated
LT1195MJ8, LT1195CJ8: T = T + (P × 100°C/W)
temperatures. Do not operate the shutdown above T > 125°C.
J
A
D
J
LT1195N:
LT1195CS:
T = T + (P × 100°C/W)
T = T + (P × 150°C/W)
J A D
Note 9: 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).
J
A
D
Note 3: Exceeding the input common-mode range may cause the output
to invert.
Note 10: Do not operate at A < 2 for T < 0°C.
V
A
Note 4: Slew rate is measured between ±1V on the output, with ±3V
input step.
Note 5: Full power bandwidth is calculated from the slew rate
measurement: FPBW = SR/2πV
P.
4
LT1195
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Input Bias Current vs
Common-Mode Voltage vs
Input Bias Current vs
Temperature
Common-Mode Voltage
Temperature
+
V
100
0
3.0
2.5
2.0
1.5
1.0
0.5
0
V
S
= ±5V
V
S
= ±5V
–0.5
–1.0
–1.5
–2.0
+I
B
+
V
= 1.8V TO 9V
–100
–200
–300
–400
–I
B
–55°C
2.0
1.5
1.0
0.5
I
OS
+
25°C
V
= –1.8V TO –9V
125°C
–
V
–0.5
–50 –25
0
25
50
75
100 125
–5 –4 –3 –2 –1
0
1
2
3
4
5
–50 –25
0
25
50
75
100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
COMMON-MODE VOLTAGE (V)
1195 G03
1195 G01
1195 G02
Equivalent Input Noise Voltage
vs Frequency
Equivalent Input Noise Current
vs Frequency
Supply Current vs Supply Voltage
600
500
400
300
200
100
0
16
14
12
10
8
14
12
10
8
V
T
= ±5V
V
T
= ±5V
= 25°C
= 100k
S
S
= 25°C
A
A
R
= 0Ω
R
S
S
–55°C
25°C
125°C
6
4
2
10
100
1k
10k
100k
10
100
1k
10k
100k
0
2
4
6
8
10
FREQUENCY (Hz)
FREQUENCY (Hz)
±SUPPLY VOLTAGE (V)
1195 G04
1195 G05
1195 G06
Shutdown Supply Current
vs Temperature
Output Voltage Swing vs
Load Resistance
Open-Loop Gain vs Temperature
5
3
1
6
5
4
3
2
1
0
10k
8k
6k
4k
2k
0
V
S
= ±5V
V
= ±5V
T
= –55°C
S
V
S
V
O
= ±5V
= ±3V
A
V
= –V + 0.6V
EE
S/D
R
= 1k
L
T
A
= 25°C
T
= 125°C
A
V
= –V + 0.4V
EE
S/D
V
S/D
= –V + 0.2V
EE
–1
T
A
= 25°C
–3
–5
R = 150Ω
L
T
= –55°C
T
A
= 125°C
A
V
= –V
EE
S/D
–50 –25
0
25
50
75
100 125
10
100
LOAD RESISTANCE (Ω)
1k
–50 –25
0
25
50
75
100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
1195 G07
1195 G08
1195 G09
5
LT1195
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Gain-Bandwidth Product vs
Supply Voltage
Open-Loop Voltage Gain vs
Gain and Phase vs Frequency
Load Resistance
100
80
60
40
20
0
100
80
60
40
20
0
20k
16k
12k
8k
60
50
40
30
20
A
V
= 20dB
V
V
T
= ±5V
= ±3V
= 25°C
PHASE
S
O
A
T
T
= –55°C
= 25°C
A
A
A
T
= 125°C
GAIN
V
= ±5V
= 25°C
= 1k
4k
S
A
L
T
R
–20
–20
0
100k
1M
10M
100M
100
1k
LOAD RESISTANCE (Ω)
10k
0
2
4
6
8
10
FREQUENCY (Hz)
±SUPPLY VOLTAGE (V)
1195 G10
1195 G11
1195 G12
Unity-Gain Frequency and Phase
Margin vs Temperature
Common-Mode Rejection Ratio
vs Frequency
Output Impedance vs Frequency
90
80
70
60
50
40
30
20
60
100
90
80
70
60
50
40
30
100
10
V
= ±5V
= 1k
V
T
= ±5V
V
T
= ±5V
= 25°C
= 1k
S
L
S
A
S
UNITY-GAIN
FREQUENCY
R
= 25°C
A
50
40
30
20
10
0
R
L
UNITY-GAIN
PHASE MARGIN
A
= 10
V
1
A
= 1
V
0.1
0.01
100k
1M
10M
100M
50
TEMPERATURE (°C)
75
100 125
1k
10k
100k
FREQUENCY (Hz)
1M
10M
100M
–50 –25
0
25
FREQUENCY (Hz)
1195 G15
1195 G14
1195 G13
Power Supply Rejection Ratio
vs Frequency
Output Short-Circuit Current
vs Temperature
±Output Swing vs Supply Voltage
+
V
36
35
34
33
32
31
30
–0.7
–0.8
–0.9
–1.0
–1.1
0.5
80
60
V
S
= ±5V
V
= ±5V
S
A
T
= 25°C
125°C
V
= ±300mV
RIPPLE
25°C
+PSRR
–PSRR
–55°C
40
R
= R
FB
L
±1.8V ≤ V ≤ ±9V
125°C
25°C
S
20
0.4
0.3
0
–55°C
8
0.2
0.1
–20
–
–50 –25
0
25
50
75
100 125
1k
10k
100k
1M
10M
100M
0
2
4
6
10
V
TEMPERATURE (°C)
FREQUENCY (Hz)
SUPPLY VOLTAGE (V)
1195 G16
1195 G17
1195 G18
6
LT1195
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Output Voltage Step vs
Settling Time, AV = –1
Output Voltage Step vs
Settling Time, AV = 1
Slew Rate vs Temperature
250
200
150
4
2
4
2
V
T
= ±5V
= 25°C
= 1k
V
= ±5V
= 1k
= ±2V
= –1
V
T
= ±5V
= 25°C
= 1k
S
S
FB
O
V
S
R
V
A
A
R
R
L
L
A
10mV
10mV
10mV
1mV
1mV
–SLEW RATE
+SLEW RATE
0
0
1mV
–2
–4
–2
–4
10mV
1mV
300
200
SETTLING TIME (ns)
0
100
300
400
200
100
SETTLING TIME (ns)
–50 –25
0
25
50
75
100 125
0
400
TEMPERATURE (°C)
1195 G21
1195 G19
1195 G20
Large-Signal Transient Response
Large-Signal Transient Response
A = 1, R = 1k
A = –1, R = 1k
V
L
V
L
1195 G23
1195 G22
Overload Recovery
5V
3
2
7
+
6
LT1195
4
–
8
1
INPUT OFFSET VOLTAGE CAN BE ADJUSTED OVER A
±150mV RANGE WITH A 1k to 10k POTENTIOMETER.
1195 G25
A = 1, V = 11V
P-P
V
IN
1195 G24
7
LT1195
PPLICATI
O U
W
U
A
S I FOR ATIO
Power Supply Bypassing
receiving end (75Ω to ground) to absorb unwanted en-
ergy. The best performance can be obtained by double
termination(75Ω inserieswiththeoutputoftheamplifier,
and 75Ω to ground at the other end of the cable). This
termination is preferred because reflected energy is ab-
sorbed at each end of the cable. When using the double
terminationtechniqueitisimportanttonotethatthesignal
is attenuated by a factor of 2, or 6dB. This can be compen-
sated for by taking a gain of 2, or 6dB in the amplifier.
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 applicationsrequiring good settlingtime, itis 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
lowcostvideocabledriver.The±20mAguaranteedoutput
current enables the LT1195 to easily deliver 6VP-P into
150Ω, while operating on ±5V supplies.
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
shutdownbytakingpin5toV–. Inshutdown, theamplifier
dissipates15mWwhilemaintainingatruehighimpedance
output state of 15k in parallel with the feedback resistors.
The amplifiers must be used in a noninverting configura-
tion 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.
Double-Terminated Cable Driver
5V
3
7
+
CABLE
75Ω
6
LT1195
2
–
4
R
FB
75Ω
R
G
–5V
1195 AI01
Cable Driver Voltage Gain vs Frequency
8
6
4
A
R
R
= 2
FB
= 330Ω
V
= 1k
2
0
Output Shutdown
G
A
R
R
= 1
FB
= 1k
V
–2
= 1k
G
–4
–6
–8
–10
–12
V
= ±5V
= 25°C
S
A
T
100k
1M
10M
100M
FREQUENCY (Hz)
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
8
LT1195
O U
W
U
PPLICATI
A
S I FOR ATIO
Output Shutdown
Single 5V Video Amplifier
V
IN
10µF
5V
5V
+
3
1k
R
7
1000µF
+
+
75Ω
6
LT1195
4
2
R1
3k
–
R
FB
10k
75Ω
1k
G
1k
+
1195 AI05
R2
2k
100µF
1MHz SINE WAVE GATED OFF WITH SHUTDOWN PIN
V = 1, RL = 1k
A
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 condi-
tion, however too much will delay the response. Also
shown is the response to a 4VP-P input that is 150ns wide.
Themaximumoutputslewrateinthephotois30V/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,
allowingthesyncpulsestostaywithinthecommon-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
9
LT1195
PPLICATI
O U
W
U
A
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
compositevideosignalsmorethan1000feetonalowcost
twisted-pair. A bidirectional “video bus” consists of the
LT1195opampandtheLT1187videodifferenceamplifier.
A pair of LT1195s at TRANSMIT 1, is used to generate
differential signals to drive the line which is back-termi-
nated 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
systemfrom750kHzto4MHz. Thisbandwidthisadequate
to pass a 3.58MHz chrome subcarrier, and the 4.5MHz
soundsubcarrier.Attenuationinthecablecanbecompen-
sated 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
generatedifferentialsignalsforTRANSMIT2. Cabletermi-
nation is made up of 15Ω and 33Ω attentuator to reduce
the differentialinputsignaltotheLT1187. Maximuminput
1195 A109
Multiburst Pattern Passed Through
1000 Feet of Twisted-Pair
signal for the LT1187 is 760mVP-P
.
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
10
LT1195
O U
S
W
U
PPLICATI
A
I FOR ATIO
Bidirectional Video Bus
TRANSMIT 1
TRANSMIT 2
3
3
+
+
6
6
1k
2
1k
LT1195
LT1195
75Ω
75Ω
2
–
–
1k
1k
1k
1k
1k
1k
2
2
–
–
6
6
LT1195
LT1195
3
3
+
+
33Ω
33Ω
33Ω
15Ω
33Ω
1000 FT
TWISTED-PAIR
S/D
S/D
15Ω
3
3
5
+
–
+
+
5
15Ω
15Ω
2
2
75Ω
75Ω
6
–
+
–
6
LT1187
1
LT1187
R
1
8
8
R
–
FB
FB
300Ω
300Ω
1000pF
50Ω
1000pF
50Ω
R
G
R
G
300Ω
300Ω
RECEIVE 1
1195 AI12
RECEIVE 2
W
W
SIWPLIFIED SCHEWATIC
+
V
7
V
V
BIAS
BIAS
C
M
+
–
3
2
C
FF
V
OUT
6
+V
+V
*
–
V
4
5
1
8
BAL
S/D
BAL
1195 SS
* SUBSTRATE DIODE, DO NOT FORWARD BIAS
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
11
LT1195
U
Dimensions in inches (millimeters) unless otherwise noted.
PACKAGE DESCRIPTIO
J8 Package
8-Lead Ceramic DIP
CORNER LEADS OPTION
(4 PLCS)
0.405
(10.287)
MAX
0.023 – 0.045
0.200
(5.080)
MAX
0.005
(0.127)
MIN
0.290 – 0.320
(7.366 – 8.128)
(0.58 – 1.14)
HALF LEAD
OPTION
6
5
4
8
7
0.045 – 0.065
0.015 – 0.060
(1.14 – 1.65)
FULL LEAD
OPTION
(0.381 – 1.524)
0.025
0.220 – 0.310
(5.588 – 7.874)
(0.635)
RAD TYP
0.008 – 0.018
(0.203 – 0.460)
0° – 15°
1
2
3
0.045 – 0.065
(1.14 – 1.65)
0.385 ± 0.025
(9.779 ± 0.635)
0.125
3.175
MIN
0.100 ± 0.010
0.014 – 0.026
(2.540 ± 0.254)
(0.360 – 0.660)
J8 0293
N8 Package
8-Lead Plastic DIP
0.400
(10.160)
MAX
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.320
(7.620 – 8.128)
0.045 – 0.065
(1.143 – 1.651)
8
1
7
6
5
4
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
0.250 ± 0.010
(6.350 ± 0.254)
0.125
(3.175)
MIN
0.020
(0.508)
MIN
+0.025
–0.015
0.045 ± 0.015
(1.143 ± 0.381)
0.325
+0.635
8.255
2
3
(
)
–0.381
0.100 ± 0.010
(2.540 ± 0.254)
0.018 ± 0.003
(0.457 ± 0.076)
N8 0392
S8 Package
8-Lead Plastic SOIC
0.189 – 0.197
(4.801 – 5.004)
7
5
8
6
0.010 – 0.020
(0.254 – 0.508)
× 45°
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
0.008 – 0.010
(0.203 – 0.254)
0.228 – 0.244
0.150 – 0.157
(5.791 – 6.197)
(3.810 – 3.988)
0.016 – 0.050
0.406 – 1.270
0.050
(1.270)
BSC
0.014 – 0.019
(0.355 – 0.483)
0°– 8° TYP
1
3
4
2
SO8 0392
LT/GP 0293 10K REV 0 • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1993
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
12
●
●
(408) 432-1900 FAX: (408) 434-0507 TELEX: 499-3977
相关型号：
LT119AJ883B
IC DUAL COMPARATOR, 10000 uV OFFSET-MAX, 1300 ns RESPONSE TIME, CDIP14, 0.300 INCH, CERDIP-14, Comparator
Linear
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