NSC LM7121IMX

LM7121
235 MHz Tiny Low Power Voltage Feedback Amplifier
General Description
Features
The LM7121 is a high performance operational amplifier
which addresses the increasing AC performance needs of
video and imaging applications, and the size and power constraints of portable applications.
The LM7121 can operate over a wide dynamic range of supply voltages, from 5V (single supply) up to ± 15V (see the Application Information section for more details). It offers an excellent speed-power product delivering 1300V/µs and 235
MHz Bandwidth (−3 dB, AV = +1). Another key feature of this
operational amplifier is stability while driving unlimited capacitive loads.
Due to its Tiny SOT23-5 package, the LM7121 is ideal for
designs where space and weight are the critical parameters.
The benefits of the Tiny package are evident in small portable electronic devices, such as cameras, and PC video
cards. Tiny amplifiers are so small that they can be placed
anywhere on a board close to the signal source or near the
input to an A/D converter.
(Typical unless otherwise noted) VS = ± 15V
n Easy to use voltage feedback topology
n Stable with unlimited capacitive loads
n Tiny SOT23-5 package — typical circuit layout takes half
the space of SO-8 designs
n Unity gain frequency: 175 MHz
n Bandwidth (−3 dB, AV = +1, RL = 100Ω): 235 MHz
n Slew rate: 1300V/µs
n Supply Voltages SO-8: 5V to ± 15V
SOT23-5: 5V to ± 5V
n Characterized for: +5V, ± 5V, ± 15V
n Low supply current: 5.3 mA
Applications
n
n
n
n
n
n
Scanners, color fax, digital copiers
PC video cards
Cable drivers
Digital cameras
ADC/DAC buffers
Set-top boxes
Connection Diagrams
8-Pin SO-8
5-Pin SOT23
DS012348-2
DS012348-1
Top View
Top View
Ordering Information
Package
8-Pin SO-8
5-Pin SOT23-5
Ordering Information
NSC Drawing
Package
Number
Marking
LM7121IM
M08A
LM7121IM
Rails
LM7121IMX
M08A
LM7121IM
2.5k Tape and Reel
LM7121IM5
MA05A
A03A
1k Tape and Reel
LM7121IM5X
MA05A
A03A
3k Tape and Reel
© 1999 National Semiconductor Corporation
DS012348
Supplied As
www.national.com
LM7121 235 MHz Tiny Low Power Voltage Feedback Amplifier
August 1999
Absolute Maximum Ratings (Note 1)
Storage Temperature Range
Junction Temperature (Note 4)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance (Note 2)
Differential Input Voltage (Note 7)
Voltage at Input/Output Pin
Supply Voltage (V+–V−)
Output Short Circuit to Ground
(Note 3)
Lead Temperature
(soldering, 10 sec)
−65˚C to +150˚C
150˚C
Operating Ratings (Note 1)
2000V
± 2V
(V+)−1.4V, (V−)+1.4V
36V
4.5V ≤ VS ≤ 33V
4.5V ≤ VS ≤ 11V
−40˚C ≤ TJ ≤ +85˚C
Supply Voltage: SO-8
SOT23-5
Junction Temperature Range
Thermal Resistance (θJA)
M Package, 8-pin Surface Mount
SOT23-5 Package
Continuous
260˚C
260˚C
165˚C/W
325˚C/W
± 15V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = +15V, V− = −15V, VCM = VO = 0V and RL > 1 MΩ.
Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
VOS
IB
IOS
RIN
Input Offset Voltage
0.9
Input Bias Current
5.2
Input Offset Current
Input Resistance
0.04
µA
7
max
MΩ
Common Mode
−10V ≤ VCM ≤ 10V
93
10V ≤ V+ ≤ 15V
86
Rejection Ratio
Rejection Ratio
−15V ≤ V− ≤ −10V
81
Rejection Ratio
Input Common-Mode
4.3
MΩ
CMRR
VCM
max
10
2.3
Negative Power Supply
µA
12
3.4
Common Mode
−PSRR
9.5
Differential Mode
Input Capacitance
Positive Power Supply
mV
max
Common Mode
CIN
+PSRR
8
15
CMRR ≥ 70 dB
13
pF
73
dB
70
min
70
dB
68
min
68
dB
65
min
11
Voltage Range
V
min
−13
−11
V
max
AV
Large Signal
RL = 2 kΩ, VO = 20 VPP
72
Voltage Gain
VO
Output Swing
RL = 2 kΩ
13.4
−13.4
RL = 150Ω
10.2
−7.0
ISC
Output Short Circuit
Sourcing
71
Current
Sinking
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52
2
65
dB
57
min
11.1
V
10.8
min
−11.2
V
−11.0
max
7.75
V
7.0
min
−5.0
V
−4.8
max
54
mA
44
min
39
mA
34
min
± 15V DC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = +15V, V− = −15V, VCM = VO = 0V and RL > 1 MΩ.
Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
Supply Current
IS
5.3
6.6
mA
7.5
max
± 15V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 15V, V− = −15V, VCM = VO = 0V and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
SR
1300
V/µs
(Note 8)
AV = +2, RL = 1 kΩ,
VO = 20 VPP
RL = 1 kΩ
175
MHz
Slew Rate
GBW
Unity Gain-Bandwidth
φm
Phase Margin
f (−3 dB)
Bandwidth
63
Deg
RL = 100Ω, AV = +1
RL = 100Ω, AV = +2
235
MHz
Settling Time
10 VPP Step, to 0.1%,
RL = 500Ω
74
ns
Rise and Fall Time
5.3
ns
(Notes 9, 10)
ts
50
AD
Differential Gain
φD
Differential Phase
AV = +2, RL = 100Ω,
VO = 0.4 VPP
AV = +2, RL = 150Ω
AV = +2, RL = 150Ω
en
Input-Referred
f = 10 kHz
17
f = 10 kHz
1.9
tr, tf
(Note 10)
0.3
%
0.65
Deg
Voltage Noise
Input-Referred
in
Current Noise
T.H.D.
Total Harmonic Distortion
2 VPP Output, RL = 150Ω,
AV = +2, f = 1 MHz
2 VPP Output, RL = 150Ω,
%
0.065
0.52
AV = +2, f = 5 MHz
± 5V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5V, V− = −5V, VCM = VO = 0V and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
VOS
IB
IOS
RIN
Input Offset Voltage
1.6
Input Bias Current
5.5
Input Offset Current
Input Resistance
0.07
8
mV
15
max
9.5
µA
12
max
4.3
µA
7.0
max
Common Mode
6.8
MΩ
Differential Mode
3.4
MΩ
3
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± 5V DC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5V, V− = −5V, VCM = VO = 0V and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
CIN
Input Capacitance
Common Mode
2.3
CMRR
Common Mode
−2V ≤ VCM ≤ 2V
75
+PSRR
Positive Power Supply
3V ≤ V+ ≤ 5V
89
Rejection Ratio
Rejection Ratio
−PSRR
Negative Power Supply
−5V ≤ V− ≤ −3V
78
Rejection Ratio
VCM
Input Common Mode
CMRR ≥ 60 dB
3
pF
65
dB
60
min
65
dB
60
min
65
dB
60
min
2.5
Voltage Range
V
min
−3
−2.5
V
max
AV
Large Signal
RL = 2 kΩ, VO = 3 VPP
66
Voltage Gain
VO
Output Swing
RL = 2 kΩ
3.62
−3.62
RL = 150Ω
3.1
−2.8
ISC
Output Short Circuit
Sourcing
53
Current
Sinking
IS
29
Supply Current
5.1
60
dB
58
min
3.0
V
2.75
min
−3.0
V
−2.70
max
2.5
V
2.3
min
−2.15
V
−2.00
max
38
mA
33
min
21
mA
19
min
6.4
mA
7.2
max
± 5V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5V, V− = −5V, VCM = VO = 0V and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
SR
Slew Rate
(Note 8)
GBW
Unity Gain-Bandwidth
φm
Phase Margin
f (−3 dB)
Bandwidth
(Notes 9, 10)
ts
tr, tf
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520
V/µs
RL = 1 kΩ
RL = 1 kΩ
RL = 100Ω, AV = +1
RL = 100Ω, AV = +2
105
MHz
74
Deg
160
MHz
50
Settling Time
5 VPP Step, to 0.1%,
RL = 500Ω
65
ns
Rise and Fall Time
AV = +2, RL = 100Ω,
VO = 0.4 VPP
AV = +2, RL = 150Ω
5.8
ns
0.3
%
(Note 10)
AD
AV = +2, RL = 1 kΩ,
VO = 6 VPP
Differential Gain
4
± 5V AC Electrical Characteristics
(Continued)
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = 5V, V− = −5V, VCM = VO = 0V and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
φD
Differential Phase
en
Input-Referred
AV = +2, RL = 150Ω
f = 10 kHz
0.65
Deg
17
Voltage Noise
Input-Referred
in
f = 10 kHz
2
Current Noise
T.H.D.
Total Harmonic Distortion
2 VPP Output, RL = 150Ω,
AV = +2, f = 1 MHz
2 VPP Output, RL = 150Ω,
%
0.1
0.6
AV = +2, f = 5 MHz
+5V DC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = +5V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
VOS
Input Offset Voltage
IB
Input Bias Current
IOS
Input Offset Current
RIN
Input Resistance
Common Mode
CIN
Input Capacitance
CMRR
Common Mode
2.4
mV
4
µA
0.04
µA
2.6
MΩ
Differential Mode
3.4
MΩ
Common Mode
2.3
pF
2V ≤ VCM ≤ 3V
65
dB
4.6V ≤ V+ ≤ 5V
85
dB
0V ≤ V− ≤ 0.4V
61
dB
CMRR ≥ 45 dB
3.5
Rejection Ratio
+PSRR
Positive Power Supply
Rejection Ratio
−PSRR
Negative Power Supply
Rejection Ratio
VCM
Input Common-Mode
Voltage Range
V
min
1.5
V
max
AV
Large Signal
RL = 2 kΩ to V+/2
64
dB
3.7
V
Voltage Gain
VO
ISC
IS
Output Swing
RL = 2 kΩ to V+/2, High
RL = 2 kΩ to V+/2, Low
RL = 150Ω to V+/2, High
RL = 150Ω to V+/2, Low
1.3
3.48
1.59
Output Short Circuit
Sourcing
33
Current
Sinking
20
mA
4.8
mA
Supply Current
5
mA
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+5V AC Electrical Characteristics
Unless otherwise specified, all limits guaranteed for TJ = 25˚C, V+ = +5V, V− = 0V, VCM = VO = V+/2 and RL > 1 MΩ. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Conditions
Typ
(Note 5)
LM7121I
Units
Limit
(Note 6)
SR
AV = +2, RL = 1 kΩ to
V+/2, VO = 1.8 VPP
Slew Rate
(Note 8)
Rise and Fall Time
RL = 1k, to V+/2
RL = 1k to V+/2
RL = 100Ω to V+/2, AV = +1
RL = 100Ω to V+/2, AV = +2
AV = +2, RL = 100Ω,
(Note 10)
VO = 0.2 VPP
Total Harmonic Distortion
0.6 VPP Output, RL = 150Ω,
AV = +2, f = 1 MHz
0.6 VPP Output, RL = 150Ω,
AV = +2, f = 5 MHz
GBW
Unity Gain-Bandwidth
φm
Phase Margin
f (−3 dB)
Bandwidth
(Notes 9, 10)
tr, tf
T.H.D.
145
V/µs
80
MHz
70
Deg
200
MHz
45
8
ns
0.067
%
0.33
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Human body model, 1.5 kΩ in series with 100 pF.
Note 3: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the
maximum allowed junction temperature of 150˚C.
Note 4: The maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD =
(TJ(max)–TA)/θJA. All numbers apply for packages soldered directly into a PC board.
Note 5: Typical Values represent the most likely parametric norm.
Note 6: All limits are guaranteed by testing or statistical analysis.
Note 7: Differential input voltage is measured at VS = ± 15V.
Note 8: Slew rate is the average of the rising and fallng slew rates.
Note 9: Unity gain operation for ± 5V and ± 15V supplies is with a feedback network of 510Ω and 3 pF in parallel (see the Application Information section). For +5V
single supply operation, feedback is a direct short from the output to the inverting input.
Note 10: AV = +2 operation with 2 kΩ resistors and 2 pF capacitor from summing node to ground.
Typical Performance Characteristics
Supply Current vs
Supply Voltage
TA = 25˚C, RL = 1 MΩ. unless otherwise specified
Supply Current vs
Temperature
Input Offset Voltage
vs Temperature
DS012348-66
DS012348-67
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6
DS012348-68
Typical Performance Characteristics
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Input Offset Voltage vs
Common Mode Voltage
@ VS = ± 15V
Input Bias Current
vs Temperature
DS012348-76
DS012348-69
Short Circuit Current
vs Temperature (Sourcing)
Input Offset Voltage vs
Common Mode Voltage
@ VS = ± 5V
Short Circuit Current
vs Temperature (Sinking)
Output Voltage vs Output
Current (ISINK, VS = ± 15V)
DS012348-79
DS012348-78
Output Voltage vs Output
Current (ISOURCE, VS = ± 15V)
DS012348-77
Output Voltage vs Output
Current (ISOURCE, VS = ± 5V)
DS012348-72
DS012348-71
7
DS012348-70
Output Voltage vs Output
Current (ISINK, VS = ± 5V)
DS012348-73
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Typical Performance Characteristics
Output Voltage vs Output
Current (ISOURCE, VS = +5V)
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Output Voltage vs Output
Current (ISINK, VS = +5V)
DS012348-88
DS012348-5
DS012348-4
Open Loop Frequency
Response
DS012348-89
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Open Loop Frequency
Response
PSRR vs Frequency
Open Loop Frequency
Response
DS012348-3
DS012348-75
DS012348-74
PSRR vs Frequency
CMRR vs Frequency
Unity Gain Frequency vs
Supply Voltage
DS012348-90
8
DS012348-24
Typical Performance Characteristics
GBWP @ 10 MHz
vs Supply Voltage
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Large Signal Voltage Gain
vs Load, VS = ± 15V
DS012348-25
Input Voltage
Noise vs Frequency
Large Signal Voltage Gain
vs Load, VS = ± 5V
Input Current
Noise vs Frequency
DS012348-27
Input Current
Noise vs Frequency
DS012348-97
DS012348-96
Input Voltage
Noise vs Frequency
DS012348-28
Slew Rate vs Supply Voltage
DS012348-30
DS012348-31
9
DS012348-29
Slew Rate vs Input Voltage
DS012348-32
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Typical Performance Characteristics
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Slew Rate vs
Load Capacitance
Slew Rate vs Input Voltage
Large Signal Pulse Response,
AV = −1, VS = ± 15V
DS012348-35
DS012348-33
Large Signal Pulse Response,
AV = −1, VS = ± 5V
DS012348-34
Large Signal Pulse Response,
AV = −1, VS = +5V
DS012348-37
DS012348-36
Large Signal Pulse Response,
AV = +1, VS = ± 5V
DS012348-38
Large Signal Pulse Response,
AV = +1, VS = +5V
DS012348-40
DS012348-39
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Large Signal Pulse Response,
AV = +1, VS = ± 15V
10
Large Signal Pulse Response,
AV = +2, VS = ± 15V
DS012348-41
Typical Performance Characteristics
Large Signal Pulse Response,
AV = +2, VS = ± 5V
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Large Signal Pulse Response,
AV = +2, VS = +5V
DS012348-42
DS012348-43
Small Signal Pulse Response,
AV = −1, VS = ± 5V,
RL = 100Ω
Small Signal Pulse Response,
AV = −1, VS = +5V,
RL = 100Ω
Small Signal Pulse Response,
AV = −1, VS = ± 15V, RL = 100Ω
DS012348-44
Small Signal Pulse Response,
AV = +1, VS = ± 15V,
RL = 100Ω
DS012348-45
DS012348-46
Small Signal Pulse Response,
AV = +1, VS = ± 5V,
RL = 100Ω
Small Signal Pulse Response,
AV = +1, VS = +5V,
RL = 100Ω
DS012348-48
DS012348-49
11
DS012348-47
Small Signal Pulse Response,
AV = +2, VS = ± 15V,
RL = 100Ω
DS012348-50
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Typical Performance Characteristics
Small Signal Pulse Response,
AV = +2, VS = ± 5V,
RL = 100Ω
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Small Signal Pulse Response,
AV = +2, VS = +5V,
RL = 100Ω
DS012348-51
Closed Loop Frequency
Response vs Temperature
VS = ± 15V, AV = +1, RL = 100Ω
DS012348-52
DS012348-53
Closed Loop Frequency
Response vs Temperature
VS = ± 5V, AV = +1, RL = 100Ω
Closed Loop Frequency
Response vs Temperature
VS = +5V, AV = +1, RL = 100Ω
Closed Loop Frequency
Response vs Temperature
VS = ± 15V, AV = +2, RL = 100Ω
DS012348-55
DS012348-54
DS012348-58
Closed Loop Frequency
Response vs Temperature
VS = ± 5V, AV = +2, RL = 100Ω
Closed Loop Frequency
Response vs Temperature
VS = +5V, AV = +2, RL = 100Ω
DS012348-59
Closed Loop Frequency
Response vs Capacitive
Load (AV = +1, VS = ± 15V)
DS012348-60
DS012348-61
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12
Typical Performance Characteristics
Closed Loop Frequency
Response vs Capacitive
Load (AV = +1, VS = ± 5V)
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Closed Loop Frequency
Response vs Capacitive
Load (AV = +2, VS = ± 15V)
DS012348-62
Total Harmonic Distortion
vs Frequency
Closed Loop Frequency
Response vs Capacitive
Load (AV = +2, VS = ± 5V)
DS012348-63
Total Harmonic Distortion
vs Frequency
DS012348-80
Total Harmonic Distortion
vs Frequency
DS012348-64
Total Harmonic Distortion
vs Frequency
DS012348-81
Undistorted Output Swing
vs Frequency
DS012348-82
Undistorted Output Swing
vs Frequency
DS012348-85
13
DS012348-83
DS012348-84
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Typical Performance Characteristics
TA = 25˚C, RL = 1 MΩ. unless otherwise specified (Continued)
Undistorted Output Swing
vs Frequency
Total Power Dissipation
vs Ambient Temperature
DS012348-86
DS012348-65
Application Information
In determining maximum operable temperature of the device, make sure the total power dissipation of the device is
considered; this includes the power dissipated in the device
with a load connected to the output as well as the nominal
dissipation of the op amp.
The device is capable of tolerating momentary short circits
from its output to ground but prolonged operation in this
mode will damage the device, if the maximum allowed junction temperation is exceeded.
The table below, depicts the maximum operating supply voltage for each package type:
TABLE 1. Maximum Supply Voltage Values
SOT23-5
SO-8
Single Supply
10V
30V
Dual Supplies
± 5V
± 15V
Stable unity gain operation is possible with supply voltage of
5V for all capacitive loads. This allows the possibility of using
the device in portable applications with low supply voltages
with minimum components around it.
Above a supply voltage of 6V ( ± 3V Dual supplies), an additional resistor and capacitor (shown below) should be placed
in the feedback path to achieve stability at unity gain over the
full temperature range.
APPLICATION CIRCUITS
Current Boost Circuit
The circuit in Figure 2 can be used to achieve good linearity
along with high output current capability.
DS012348-92
FIGURE 2. Simple Circuit to Improve Linearity
and Output Drive Current
DS012348-87
FIGURE 1. Typical Circuit for AV = +1
Operation (VS ≥ 6V)
By proper choice of R3, the LM7121 output can be set to
supply a minimal amount of current, thereby improving its
output linearity.
The package power dissipation should be taken into account
when operating at high ambient temperatures and/or high
power dissipative conditions. Refer to the power derating
curves in the data sheet for each type of package.
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R3 can be adjusted to allow for different loads:
R3 = 0.1 RL
The circuit above has been set for a load of 100Ω.
Reasonable speeds ( < 30 ns rise and fall times) can be expected up to 120 mAPP of load current (see Figure 3 for step
response across the load).
14
Application Information
(Continued)
DS012348-93
FIGURE 3. Waveform across a 100Ω Load
Color Video on Twisted Pairs Using Single Supply
The circuit shown in Figure 4 can be used to drive in excess
of 25 meters length of twisted pair cable with no loss of resolution or picture definition when driving a NTSC monitor at
the load end.
It is very important to keep the lead lengths to a minimum
and to provide a low impedance current path by using a
ground-plane on the board.
Caution: If RL is removed, the current balance at the output
of LM7121 would be disturbed and it would have to supply
the full amount of load current. This might damage the part if
power dissipation limit is exceeded.
15
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Application Information
(Continued)
DS012348-94
Note:
Pin numbers shown are for SO-8 package.
*Input termination of NTSC monitor.
FIGURE 4. Single Supply Differential Twister Pair Cable Transmitter/Receiver
8.5V ≤ VCC ≤ 30V
Even though the transmission line is not terminated in its
nominal characteristic impedance of about 600Ω, the resulting reflection at the load is only about 5% of the total signal
and in most cases can be neglected. Using 75Ω termination
instead, has the advantage of operating at a low impedance
and results in a higher realizable bandwidth and signal
fidelity.
Differential Gain and Differential Phase errors measured at
the load are less than 1% and 1˚ respectively.
RG and CC can be adjusted for various cable lengths to compensate for the line losses and for proper response at the
output. Values shown correspond to a twisted pair cable
length of 25 meters with about 3 turns/inch (see Figure 5 for
step response).
The supply voltage can vary from 8.5V up to 30V with the
output rise and fall times under 12 ns. With the component
values shown, the overall gain from the input to the output is
about 1.
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16
Application Information
(Continued)
DS012348-95
FIGURE 5. Step Response to a 1 VPP Input Signal Measured across the 75Ω Load
DS012348-98
(a) AV = −1
DS012348-99
CC = 2 pF for RL = 100Ω
CC = Open for RL = Open
(b) AV = +2
DS012348-A0
(c) AV = +2, Capacitive Load
DS012348-A1
RF = 0Ω, CC = Open for VS < 6V
RF = 510Ω, CC = 3 pF for VS ≥ 6V
(d) AV = +1
DS012348-A2
(e) AV = +1, VS = +5V, Single Supply Operation
FIGURE 6. Application Test Circuits
17
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Physical Dimensions
inches (millimeters) unless otherwise noted
8-Lead (0.150" Wide) Small Outline Package, JEDEC
Order Number LM7121IM or LM7121IMX
NS Package Number M08A
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18
LM7121 235 MHz Tiny Low Power Voltage Feedback Amplifier
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
5-Lead Molded SOT23-5
Order Number LM7121IM5 or LM7121IM5X
NS Package Number MA05A
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