LMH6714, LMH6720
LMH6722, LMH6722-Q1
www.ti.com
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
LMH6714/ LMH6720/ LMH6722/ LMH6722Q Wideband Video Op Amp; Single, Single with
Shutdown and Quad
Check for Samples: LMH6714, LMH6720, LMH6722, LMH6722-Q1
FEATURES
1
•
2
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
400MHz (AV = +2V/V, VOUT = 500mVPP) −3dB
BW
250MHz (AV = +2V/V, VOUT = 2VPP) -3dB BW
0.1dB Gain Flatness to 120MHz
Low Power: 5.6mA
TTL Compatible Shutdown Pin (LMH6720)
Very Low Diff. Gain, Phase: 0.01%, 0.01°
(LMH6714)
−58 HD2/ −70 HD3 at 20MHz
Fast Slew Rate: 1800V/μs
Low Shutdown Current: 500uA (LMH6720)
11ns Turn on Time (LMH6720)
7ns Shutdown Time (LMH6720)
Unity Gain Stable
Improved Replacement for
CLC400,401,402,404,406 and 446 (LMH6714)
Improved Replacement for CLC405 (LMH6720)
Improved Replacement for CLC415 (LMH6722)
LMH6722QSD is AEC-Q100 Grade 1 Qualified
and is Manufactured on an Automotive Grade
Flow
DESCRIPTION
The LMH6714/LMH6720/LMH6722 series combine
Texas Instruments' VIP10 high speed complementary
bipolar process with Texas Instruments' current
feedback topology to produce a very high speed op
amp. These amplifiers provide a 400MHz small signal
bandwidth at a gain of +2V/V and a 1800V/μs slew
rate while consuming only 5.6mA from ±5V supplies.
The LMH6714/LMH6720/LMH6722 series offer
exceptional video performance with its 0.01% and
0.01° differential gain and phase errors for NTSC and
PAL video signals while driving a back terminated
75Ω load. They also offer a flat gain response of
0.1dB to 120MHz. Additionally, they can deliver 70mA
continuous output current. This level of performance
makes them an ideal op amp for broadcast quality
video systems.
The LMH6714/LMH6720/LMH6722's small packages
(SOIC, SOT-23 and WSON), low power requirement,
low
noise
and
distortion
allow
the
LMH6714/LMH6720/LMH6722 to serve portable RF
applications. The high impedance state during
shutdown makes the LMH6720 suitable for use in
multiplexing multiple high speed signals onto a
shared transmission line. The LMH6720 is also ideal
for portable applications where current draw can be
reduced with the shutdown function.
APPLICATIONS
•
•
•
•
•
•
•
HDTV, NTSC & PAL Video Systems
Video Switching and Distribution
Wideband Active Filters
Cable Drivers
High Speed Multiplexer (LMH6720)
Programmable Gain Amplifier (LMH6720)
Automotive (LMH6722Q)
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2002–2013, Texas Instruments Incorporated
LMH6714, LMH6720
LMH6722, LMH6722-Q1
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
www.ti.com
Typical Performance
Non-Inverting Small Signal Frequency Response
Differential Gain and Phase vs. Number of Video Loads
(LMH6714)
2
0.05
0.04
0.04
PHASE
-3
0
-4
-45
AV = 2, RF = 300:
-90
-5
-6 AV = 6, RF = 200:
-135
-7
-180
VO = 500mVPP
-8
1
100
10
FREQUENCY (MHz)
-225
1000
PHASE
0.03
0.03
0.02
0.02
GAIN
0.01
0.01
0
DIFFERENTIAL PHASE (°)
-2
PHASE (°)
-1
DIFFERENTIAL GAIN (%)
GAIN
0
GAIN (dB)
0.05
AV = 1, RF = 600:
1
0
1
2
3
4
VIDEO LOADS (150: EACH)
Figure 1.
Figure 2.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings (1) (2)
ESD Tolerance (3)
Human Body Model
2000V
Machine Model
200V
VCC
±6.75V
IOUT
See (4)
Common Mode Input Voltage
±VCC
Differential Input Voltage
2.2V
Maximum Junction Temperature
+150°C
−65°C to +150°C
Storage Temperature Range
Lead Temperature (soldering 10 sec)
+300°C
Storage Temperature Range
−65°C to +150°C
Shutdown Pin Voltage (5)
+VCC to VCC/2-1V
(1)
(2)
(3)
(4)
(5)
2
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 ensured. For specific specifications, see the Electrical
Characteristics tables.
If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of
JEDEC). Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).
The maximum output current (IOUT) is determined by device power dissipation limitations. See the POWER DISSIPATION section for
more details.
The shutdown pin is designed to work between 0 and VCC with split supplies (VCC = -VEE). With single supplies (VEE = ground) the
shutdown pin should not be taken below VCC/2.
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LMH6714, LMH6720
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
Operating Ratings (1)
Thermal Resistance Package
(θJA)
5-Pin SOT-23 (DBV)
232°C/W
6-Pin SOT-23 (DBV)
198°C/W
8-Pin SOIC (D)
145°C/W
14-Pin SOIC (D)
130°C/W
14-Pin TSSOP (PW)
160°C/W
14-Pin WSON (NHK)
46°C/W
Operating Temperature
−40°C to 125°C
LMH6722Q
−40°C to 85°C
All others
Supply Voltage Range
(1)
8V (±4V) to 12.5V (±6.25V)
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 ensured. For specific specifications, see the Electrical
Characteristics tables.
Electrical Characteristics
Unless specified, AV = +2, RF = 300Ω: VCC = ±5V, RL = 100Ω, LMH6714/LMH6720/LMH6722. Boldface limits apply at
temperature extremes.
Symbol
Parameter
Conditions
Min (1)
Typ (2)
Max (1)
Units
Frequency Domain Response
SSBW
−3dB Bandwidth
VOUT = 0.5VPP
345
400
MHz
LSBW
−3dB Bandwidth
VOUT = 2.0VPP
200
250
MHz
LSBW
−3dB Bandwidth, LMH6722
TSSOP package only
VOUT = 2.0VPP
170
250
MHz
Gain Flatness
VOUT = 2VPP
dB
GFP
GFR
Peaking
DC to 120MHz
0.1
Rolloff
DC to 120MHz
0.1
dB
LPD
Linear Phase Deviation
DC to 120MHz
0.5
deg
DG
Differential Gain
RL = 150Ω, 4.43MHz (LMH6714)
0.01
%
DG
Differential Gain
RL = 150Ω, 4.43MHz (LMH6720)
0.02
%
DP
Differential Phase
RL = 150Ω, 4.43MHz
0.01
deg
.5V Step
1.5
ns
2V Step
2.6
ns
12
ns
1800
V/µs
Time Domain Response
TRS
Rise and Fall Time
TRL
ts
Settling Time to 0.05%
2V Step
SR
Slew Rate
6V Step
1200
Distortion and Noise Response
HD2
2nd Harmonic Distortion
2VPP, 20MHz
−58
dBc
HD3
3rd Harmonic Distortion
2VPP, 20MHz
−70
dBc
IMD
3rd Order Intermodulation
Products
10MHz, POUT = 0dBm
−78
dBc
3.4
nV/√Hz
Equivalent Input Noise
VN
Non-Inverting Voltage
>1MHz
NICN
Inverting Current
>1MHz
10
pA/√Hz
ICN
Non-Inverting Current
>1MHz
1.2
pA/√Hz
(1)
(2)
All limits are specified by testing, design, or statistical analysis.
Typical values represent the most likely parametric norm at the time of characterization. Actual typical values may vary over time and
will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped production
material.
Copyright © 2002–2013, Texas Instruments Incorporated
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
www.ti.com
Electrical Characteristics (continued)
Unless specified, AV = +2, RF = 300Ω: VCC = ±5V, RL = 100Ω, LMH6714/LMH6720/LMH6722. Boldface limits apply at
temperature extremes.
Symbol
Parameter
Conditions
Min (1)
Typ (2)
Max (1)
Units
±0.2
±6
±8
mV
Static, DC Performance
VIO
Input Offset Voltage
DVIO
IBN
Average Drift
DIBN
IBI
Non-Inverting
±1
Inverting
−4
Average Drift
±10
±15
4
Input Bias Current
DIBI
μV/°C
8
Input Bias Current
nA/°C
±12
±20
µA
41
nA/°C
PSRR
Power Supply Rejection Ratio
DC
48
47
58
dB
CMRR
Common Mode Rejection
Ratio
DC
48
45
54
dB
ICC
Supply Current
RL = ∞
LMH6714
LMH6720
4.5
3
5.6
7.5
8
LMH6722
18
15
22.5
30
32
500
670
ICCI
Average Drift
µA
Supply Current During
Shutdown
LMH6720
mA
μA
Miscellaneous Performance
RIN
Input Resistance
Non-Inverting
2
MΩ
CIN
Input Capacitance
Non-Inverting
1.0
pF
ROUT
Output Resistance
Closed Loop
0.06
Ω
VOUT
Output Voltage Range
RL = ∞
±3.5
±3.4
±3.9
RL = 100Ω
±3.6
±3.4
±3.8
CMIR
Input Voltage Range
Common Mode
IOUT
Output Current (3)
VIN = 0V, Max Linear
Current
50
V
±2.2
V
70
mA
OFFMAX Voltage for Shutdown
LMH6720
ONMIN
Voltage for Turn On
LMH6720
2.0
IIH
Current Turn On
LMH6720, SD = 2.0V
−20
−30
2
20
30
IIL
Current Shutdown
LMH6720, SD = .8V
−600
−400
−100
IOZ
ROUT Shutdown
LMH6720, SD = .8V
0.2
1.8
MΩ
ton
Turn on Time
LMH6720
11
ns
toff
Turn off Time
LMH6720
7
ns
(3)
4
0.8
V
V
μA
μA
The maximum output current (IOUT) is determined by device power dissipation limitations. See the POWER DISSIPATION section for
more details.
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LMH6714, LMH6720
LMH6722, LMH6722-Q1
www.ti.com
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
CONNECTION DIAGRAMS
1
5
OUT
V
+
6
1
OUTPUT
5
V
-
2
V
+
+IN
+
-IN
+IN
Figure 3. 5-Pin SOT-23
(LMH6714) (Top View)
See Package Number DBV
N/C
-IN
+IN
V
-
1
2
3
4
+
+
SD
-
4
3
-IN
Figure 4. 6-Pin SOT-23
(LMH6720) (Top View)
See Package Number DBV
8
-
2
4
3
-
V
7
6
5
N/C
+
V
OUTPUT
N/C
Figure 6. 8-Pin SOIC (LMH6714) (Top View)
See Package Number D
Copyright © 2002–2013, Texas Instruments Incorporated
N/C
-IN
+IN
V
-
Figure 5. 14-Pin SOIC, TSSOP
and WSON (LMH6722) (Top View)
See Package Numbers D, PW,
and NHK
1
2
3
8
7
-
6
+
4
5
SD
+
V
OUTPUT
N/C
Figure 7. 8-Pin SOIC (LMH6720) (Top View)
See Package Number D
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LMH6714, LMH6720
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
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Typical Performance Characteristics
(V = +5V, V− = −5V, AV = 2, RF = 300Ω, RL = 100Ω Unless Specified).
+
Non-Inverting Small Signal Frequency Response
Non-Inverting Large Signal Frequency Response
2
2
AV = 1, RF = 600:
1
GAIN
RF = 300:
GAIN
-1
PHASE
-3
0
-4
-45
AV = 2, RF = 300:
GAIN (dB)
PHASE (°)
-1
-2
-3
-45
-5
-90
-5
-135
-6
-7
-180
-7
-225
1000
-8
VO = 500mVPP
100
10
FREQUENCY (MHz)
1
0
PHASE
-4
-6 AV = 6, RF = 200:
-8
AV = 1, RF = 600:
-2
-90
AV = 6, RF = 200:
-180
100
10
FREQUENCY (MHz)
1
Inverting Frequency Response
Non-Inverting Frequency Response vs. VO
2
VO = 2VPP
1
AV = -1
RF = 300:
1
0
0
-3
GAIN (dB)
-2
PHASE (°)
AV = -2
-2
PHASE
-3
-4
-45
-5
-90
-5
-45
-135
-6
-7
-180
-7
-8
-225
1000
-8
-6
AV = -6
1
10
100
FREQUENCY (MHz)
0
-4
VO = 2VPP
RF = 300:
-135
VO = 4VPP
Inverting Frequency Response vs. VO
Harmonic Distortion vs. Frequency
0
0
-225
1000
Figure 11.
2
VO = 2VPP
-10
VO = 2VPP
GAIN
-180
100
10
FREQUENCY (MHz)
Figure 10.
1
-90
AV = 2V/V
1
PHASE (°)
VO = 1VPP
-1
-1
GAIN (dB)
VO = .5VPP
GAIN
0
-2
PHASE
0
-4
-45
-5
-90
-6
AV = -1V/V
-7
VO = .5VPP
RF = 300:
-8
10
100
FREQUENCY (MHz)
Figure 12.
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DISTORTION (dBc)
VO = 4VPP
PHASE (°)
-20
-1
GAIN (dB)
-225
1000
Figure 9.
2
6
-135
VO = 2VPP
Figure 8.
-3
PHASE (°)
0
0
GAIN (dB)
AV = 2,
1
-30
-40
-50
-60
-70
-135
-80
-180
-90
100 -225
0
-100
HD2
HD3
1
10
FREQUENCY (MHz)
100
Figure 13.
Copyright © 2002–2013, Texas Instruments Incorporated
Product Folder Links: LMH6714 LMH6720 LMH6722 LMH6722-Q1
LMH6714, LMH6720
LMH6722, LMH6722-Q1
www.ti.com
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
Typical Performance Characteristics (continued)
−
+
(V = +5V, V = −5V, AV = 2, RF = 300Ω, RL = 100Ω Unless Specified).
2nd Harmonic Distortion vs. VOUT
3rd Harmonic Distortion vs. VOUT
0
-10
-10
-20
-20
-30
DISTORTION (dBc)
DISTORTION (dBc)
0
50MHz
-40
-50
10MHz
-60
-70
-30
-40
50MHz
-50
-60
-70
-80
10MHz
-80
5MHz
-90
-90
5MHz
-100
-100
0.5
1
1.5
2
2.5
VOUT (VPP)
3
3.5
4
0
0.5
1
3
3.5
4
0.04
0.04
PHASE
0.03
0.03
0.02
0.02
GAIN
0.01
0.01
0
DIFFERENTIAL GAIN (%)
DG/DP (LMH6720)
0.05
DIFFERENTIAL PHASE (°)
DG/DP (LMH6714)
DIFFERENTIAL GAIN (%)
2.5
Figure 15.
0.05
0.08
0.08
0.07
0.07
0.06
0.06
0.05
0.05
3
0.04
0.04
GAIN
PHASE
0.03
0.03
0.02
0.02
0.01
0.01
0
0
0
2
2
VOUT (VPP)
Figure 14.
1
1.5
2
1
4
DIFFERENTIAL PHASE (°)
0
3
4
NUMBER OF VIDEO LOADS
VIDEO LOADS (150: EACH)
Figure 16.
Figure 17.
DG/DP (LMH6722)
Large Signal Pulse Response
0.04
4
0.04
AV = 2V/V
0.03
PHASE
0.02
0.02
GAIN
0.01
0.01
2
1
VOUT (V)
0.03
DIFFERENTIAL PHASE (°)
DIFFERENTIAL GAIN (%)
3
0
-1
-2
-3
0
0
1
2
3
VIDEO LOADS (150: EACH)
Figure 18.
Copyright © 2002–2013, Texas Instruments Incorporated
4
-4
0
5 10 15 20 25 30 35 40 45 50
TIME (nS)
Figure 19.
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Typical Performance Characteristics (continued)
−
+
(V = +5V, V = −5V, AV = 2, RF = 300Ω, RL = 100Ω Unless Specified).
Small Signal Pulse Response
Closed Loop Output Resistance
1000
1.5
1
100
AV = +2V/V
RF = 300:
ROUT (:)
VOUT (V)
0.5
0
10
1
AV = -1V/V
-0.5
RF = 300:
0.1
-1
0.01
0.01
-1.5
0
5
10 15 20 25 30 35 40 45 50
1
100
10
TIME (nS)
FREQUENCY (MHz)
Figure 20.
Figure 21.
Open Loop Transimpedance Z(s)
1000
PSRR vs. Frequency
130
0
120
-10
110
-20
MAGNITUDE
90
0
80
-45
-PSRR
PSRR (dB)
100
PHASE (°)
TRANSIMPEDANCE (dB:)
0.1
PHASE
-30
-40
70
-90
-50
60
-135
-60
-180
1000
-70
+PSRR
50
0.01
0.1
1
10
100
0.1
1
FREQUENCY (MHz)
10
100
1000
FREQUENCY (MHz)
Figure 22.
Figure 23.
CMRR vs. Frequency
Frequency Response vs. RF
1
0
0
-10
RF = 147:
-2
-20
GAIN (dB)
CMRR (dB)
-1
-30
RF = 300:
-3
RF = 400:
-4
RF = 600:
-5
-40
-6
-50
AV = 2V/V
-7
0.1
1
100
10
FREQUENCY (MHz)
Figure 24.
8
VOUT = 0.5VPP
-8
-60
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1000
1
100
10
FREQUENCY (MHz)
1000
Figure 25.
Copyright © 2002–2013, Texas Instruments Incorporated
Product Folder Links: LMH6714 LMH6720 LMH6722 LMH6722-Q1
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
Typical Performance Characteristics (continued)
−
+
(V = +5V, V = −5V, AV = 2, RF = 300Ω, RL = 100Ω Unless Specified).
DC Errors vs. Temperature
Maximum VOUT vs. Frequency
0
IBN
-1
-0.4
-3
VOS
IBI
-0.6
-4
-5
-0.8
-6
-1
-7
-1.2
7
MAXIMUM VOUT (VPP)
-2
INPUT BIAS CURRENT (PA)
-0.2
VOS (mV)
8
0
6
5
4
3
2
-8
-1.4
-40
-20
0
20
40
60
80
1
-9
100
0.1
1
100
1000
Figure 26.
Figure 27.
3rd Order Intermodulation vs. Output Power
Crosstalk vs. Frequency (LMH6722)
for each channel with all others active
-10
-20
0
TWO EQUAL POWER
TONES CENTERED AT
LISTED FREQUENCY
-10
-20
-30
-40
-50
100MHz
-60
20MHz
-70
-30
CROSSTALK (dBc)
SPURIOUS SIGNAL LEVEL (dBc)
10
FREQUENCY (MHz)
TEMPERATURE (°C)
D
-40
-50
A
-60
-70
-80
C
-80
-90
-90
5MHz
10MHz
-100
-15 -12 -9
-6
-3
0
3
6
9
B
-100
0.1
12 15
1
100
100
1000
FREQUENCY (MHz)
OUTPUT POWER FOR EACH TONE (dBmW)
Figure 28.
Figure 29.
Noise vs. Frequency
1000
Hz)
100
100
INVERTING CURRENT
10
10
VOLTAGE
NON-INVERTING
CURRENT
1
1
1
10
100
CURRENT NOISE (pA/
VOLTAGE NOISE (nV/
Hz)
1000
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 30.
Copyright © 2002–2013, Texas Instruments Incorporated
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APPLICATION SECTION
FEEDBACK RESISTOR SELECTION
One of the key benefits of a current feedback operational amplifier is the ability to maintain optimum frequency
response independent of gain by using appropriate values for the feedback resistor (RF). The Electrical
Characteristics and Typical Performance plots specify an RF of 300Ω, a gain of +2V/V and ±5V power supplies
(unless otherwise specified). Generally, lowering RF from it's recommended value will peak the frequency
response and extend the bandwidth while increasing the value of RF will cause the frequency response to roll off
faster. Reducing the value of RF too far below it's recommended value will cause overshoot, ringing and,
eventually, oscillation.
1
0
-1
RF = 147:
GAIN (dB)
-2
RF = 300:
-3
RF = 400:
-4
RF = 600:
-5
-6
AV = 2V/V
-7
VOUT = 0.5VPP
-8
1
100
10
FREQUENCY (MHz)
1000
Figure 31. Frequency Response vs. RF
Figure 31 shows the LMH6714/LMH6720/LMH6722's frequency response as RF is varied (RL = 100Ω, AV = +2).
This plot shows that an RF of 147Ω results in peaking. An RF of 300Ω gives near maximal bandwidth and gain
flatness with good stability. An RF of 400Ω gives excellent stability with only a small bandwidth penalty. Since all
applications are slightly different it is worth some experimentation to find the optimal RF for a given circuit. Note
that it is not possible to use a current feedback amplifier with the output shorted directly to the inverting input.
The buffer configuration of the LMH6714/LMH6720/LMH6722 requires a 600Ω feedback resistor for stable
operation.
For more information see Application Note OA-13 (SNOA366) which describes the relationship between RF and
closed-loop frequency response for current feedback operational amplifiers. The value for the inverting input
impedance for the LMH6714/LMH6720/LMH6722 is approximately 180Ω. The LMH6714/LMH6720/LMH6722 is
designed for optimum performance at gains of +1 to +6 V/V and −1 to −5V/V. When using gains of ±7V/V or
more the low values of RG required will make inverting input impedances very low.
When configuring the LMH6714/LMH6720/LMH6722 for gains other than +2V/V, it is usually necessary to adjust
the value of the feedback resistor. Figure 32 and Figure 33 provide recommended feedback resistor values for a
number of gain selections.
700
SUGGESTED RF (:)
600
500
400
300
200
100
0
1
2
3
4
5
6
7
8
9
10
GAIN (V/V)
Figure 32. RF vs. Non-Inverting Gain
10
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
In the Figure 32 and Figure 33 charts, the recommended value of RF is depicted by the solid line, which starts
high, decreases to 200Ω and begins increasing again. The reason that a higher RF is required at higher gains is
the need to keep RG from decreasing too far below the output impedance of the input buffer. For the
LMH6714/LMH6720/LMH6722 the output resistance of the input buffer is approximately 180Ω and 50Ω is a
practical lower limit for RG. Due to the limitations on RG the LMH6714/LMH6720/LMH6722 begins to operate in a
gain bandwidth limited fashion for gains of ±5V/V or greater.
450
400
SUGGESTED RF (:)
350
300
250
200
150
100
50
0
1
2
3
4
5
6
7
8
9
10
GAIN (-V/V)
Figure 33. RF vs. Inverting Gain
ACTIVE FILTERS
When using any current feedback Operational Amplifier as an active filter it is important to be very careful when
using reactive components in the feedback loop. Anything that reduces the impedance of the negative feedback,
especially at higher frequencies, will almost certainly cause stability problems. Likewise capacitance on the
inverting input needs to be avoided. See Application Notes OA-07 (SNOA365) and OA-26 (SNOA387) for more
information on Active Filter applications for Current Feedback Op Amps.
Figure 34. Enable/Disable Operation
ENABLE/DISABLE OPERATION USING ±5V SUPPLIES (LMH6720 ONLY)
The LMH6720 has a TTL logic compatible disable function. Apply a logic low (2.0V), or let the pin float and the LMH6720 is enabled. Voltage, not
current, at the Disable pin determines the enable/disable state. Care must be exercised to prevent the disable pin
voltage from going more than .8V below the midpoint of the supply voltages (0V with split supplies, VCC/2 with
single supplies) doing so could cause transistor Q1 to Zener resulting in damage to the disable circuit. The core
amplifier is unaffected by this, but disable operation could become slower as a result.
Copyright © 2002–2013, Texas Instruments Incorporated
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11
LMH6714, LMH6720
LMH6722, LMH6722-Q1
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
www.ti.com
Disabled, the LMH6720 inputs and output become high impedances. While disabled the LMH6720 quiescent
current is approximately 500μA. Because of the pull up resistor on the disable circuit the ICC and IEE currents are
not balanced in the disabled state. The positive supply current (ICC) is approximately 500μA while the negative
supply current (IEE) is only 200μA. The remaining IEE current of 300μA flows through the disable pin.
The disable function can be used to create analog switches or multiplexers. Implement a single analog switch
with one LMH6720 positioned between an input and output. Create an analog multiplexer with several
LMH6720's. The LMH6720 is at it's best at a gain of 1 for multiplexer applications because there is no RG to
shunt signals to ground.
DISABLE LIMITATIONS (LMH6720 ONLY)
The feedback Resistor (RF) limits off isolation in inverting gain configurations. During shutdown the impedance of
the LMH6720 inputs and output become very high (>1MΩ), however RF and RG are the dominant factor for
effective output impedance.
Do not apply voltages greater than +VCC or less than 0V (VCC/2 single supply) to the disable pin. The input ESD
diodes will also conduct if the signal leakage through the feedback resistors brings the inverting input near either
supply rail.
+5V
C4
C2
.01PF
6.8PF
IN
+
OUT
50:
RIN
50:
ROUT
.1PF
-
C1
300:
RF
C3
.01PF
300:
6.8PF
RG
C5
-5V
Figure 35. Typical Application with Suggested Supply Bypassing
LAYOUT CONSIDERATIONS
Whenever questions about layout arise, use the evaluation board as a guide. The following Evaluation boards
are available with sample parts:
LMH6714
LMH6720
LMH6722
SOT-23
LMH730216
SOIC
LMH730227
SOT-23
LMH730216
SOIC
LMH730227
SOIC
LMH730231
TSSOP
LMH730131
To reduce parasitic capacitances, the ground plane should be removed near the input and output pins. To
reduce series inductance, trace lengths of components in the feedback loop should be minimized. For long signal
paths controlled impedance lines should be used, along with impedance matching at both ends.
Bypass capacitors should be placed as close to the device as possible. Bypass capacitors from each rail to
ground are applied in pairs. The larger electrolytic bypass capacitors can be located anywhere on the board, the
smaller ceramic capacitors should be placed as close to the device as possible. In addition Figure 35 shows a
capacitor (C1) across the supplies with no connection to ground. This capacitor is optional, however it is required
for best 2nd Harmonic suppression. If this capacitor is omitted C2 and C3 should be increased to .1μF each.
12
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LMH6714, LMH6720
LMH6722, LMH6722-Q1
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SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
VIDEO PERFORMANCE
The LMH6714/LMH6720/LMH6722 has been designed to provide excellent performance with both PAL and
NTSC composite video signals. Performance degrades as the loading is increased, therefore best performance
will be obtained with back terminated loads. The back termination reduces reflections from the transmission line
and effectively masks capacitance from the amplifier output stage. While all parts offer excellent video
performance the LMH6714 and LMH6722 are slightly better than the LMH6720.
WIDE BAND DIGITAL PROGRAMMABLE GAIN AMPLIFIER (LMH6720 ONLY)
Figure 36. Wideband Digitally Controlled Programmable Gain Amplifier
Channel Switching
Figure 37. PGA Output
As shown in Figure 36 and Figure 37 the LMH6720 can be used to construct a digitally controlled programmable
gain amplifier. Each amplifier is configured to provide a digitally selectable gain. To provide for accurate gain
settings, 1% or better tolerance is recommended on the feedback and gain resistors. The gain provided by each
digital code is arbitrary through selection of the feedback and gain resistor values.
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13
LMH6714, LMH6720
LMH6722, LMH6722-Q1
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
www.ti.com
AMPLITUDE EQUALIZATION
Sending signals over coaxial cable greater than 50 meters in length will attenuate high frequency signal
components much more than lower frequency components. An equalizer can be made to pre emphasize the
higher frequency components so that the final signal has less distortion. This process can be done at either end
of the cable. The circuit in Figure 38 shows a receiver with some additional components in the feedback loop to
equalize the incoming signal. The RC networks peak the signal at higher frequencies. This peaking is a
piecewise linear approximation of the inverse of the frequency response of the coaxial cable. Figure 39 shows
the effect of this equalization on a digital signal that has passed through 150 meters of coaxial cable. Figure 40
shows a Bode plot of the frequency response of the circuit in Figure 38 along with equations needed to design
the pole and zero frequencies. Figure 41 shows a network analyzer plot of an LMH6714/LMH6720/LMH6722 with
the following component values:
RG = 309Ω
R1 = 450Ω
C1 = 470pF
R2 = 91Ω
C2 = 68pF
Figure 38. Equalizer Circuit Schematic
Figure 39. Digital Signal without and with Equalization
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Product Folder Links: LMH6714 LMH6720 LMH6722 LMH6722-Q1
LMH6714, LMH6720
LMH6722, LMH6722-Q1
www.ti.com
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
Figure 40. Design Equations
10
8
GAIN (dB)
6
4
2
0
-2
-4
-6
10k
100k
1M
10M
100M
1G
FREQUENCY (Hz)
Figure 41. Equalizer Frequency Response
POWER DISSIPATION
Follow these steps to determine the Maximum power dissipation for the LMH6714/LMH6720/LMH6722:
1. Calculate the quiescent (no load) power: PAMP = ICC (VCC -VEE)
2. Calculate the RMS power at the output stage: POUT (RMS) = ((VCC - VOUT (RMS)) * IOUT (RMS)), where VOUT
and IOUT are the voltage and current across the external load.
3. Calculate the total RMS power: PT = PAMP + POUT
The maximum power that the LMH6714/LMH6720/LMH6722, package can dissipate at a given temperature can
be derived with the following equation:
PMAX = (150° - TA)/ θJA, where TA = Ambient temperature (°C) and θJA = Thermal resistance, from junction to
ambient, for a given package (°C/W). For the SOIC package θJA is 145°C/W, for the 5-pin SOT-23 it is 232°C/W.
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15
LMH6714, LMH6720
LMH6722, LMH6722-Q1
SNOSA39G – NOVEMBER 2002 – REVISED APRIL 2013
www.ti.com
REVISION HISTORY
Changes from Revision F (April 2013) to Revision G
•
16
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 15
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PACKAGE OPTION ADDENDUM
www.ti.com
14-Apr-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
LMH6714MA
NRND
SOIC
D
8
95
Non-RoHS
& Green
Call TI
Level-1-235C-UNLIM
-40 to 85
LMH67
14MA
LMH6714MA/NOPB
ACTIVE
SOIC
D
8
95
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
14MA
LMH6714MAX/NOPB
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
14MA
LMH6714MF
NRND
SOT-23
DBV
5
1000
Non-RoHS
& Green
Call TI
Level-1-260C-UNLIM
-40 to 85
A95A
LMH6714MF/NOPB
ACTIVE
SOT-23
DBV
5
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
A95A
LMH6714MFX/NOPB
ACTIVE
SOT-23
DBV
5
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
A95A
LMH6720MA/NOPB
ACTIVE
SOIC
D
8
95
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
20MA
LMH6720MAX/NOPB
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
20MA
LMH6720MF/NOPB
ACTIVE
SOT-23
DBV
6
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
A96A
LMH6720MFX/NOPB
ACTIVE
SOT-23
DBV
6
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
A96A
LMH6722MA
NRND
SOIC
D
14
55
Non-RoHS
& Green
Call TI
Level-1-235C-UNLIM
-40 to 85
LMH67
22MA
LMH6722MA/NOPB
ACTIVE
SOIC
D
14
55
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
22MA
LMH6722MAX
NRND
SOIC
D
14
2500
Non-RoHS
& Green
Call TI
Level-1-235C-UNLIM
-40 to 85
LMH67
22MA
LMH6722MAX/NOPB
ACTIVE
SOIC
D
14
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
22MA
LMH6722MT/NOPB
ACTIVE
TSSOP
PW
14
94
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
22MT
LMH6722MTX/NOPB
ACTIVE
TSSOP
PW
14
2500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
LMH67
22MT
LMH6722QSD/NOPB
ACTIVE
WSON
NHK
14
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
L6722Q
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
Orderable Device
14-Apr-2022
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
LMH6722QSDX/NOPB
ACTIVE
WSON
NHK
14
4500
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
L6722Q
LMH6722SD/NOPB
ACTIVE
WSON
NHK
14
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 85
L6722
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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