OPA2673
348W
2kW
2kW1mF
5W
50W
511W
511W
1/2
OPA2673
1/2
OPA2673
+12V
1:1.4
8VPP
5W
+6.0V
2VPP
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
Dual, Wideband, High Output Current
Operational Amplifier with Active Off-Line Control
Check for Samples: OPA2673
1FEATURES DESCRIPTION
2 WIDEBAND +12V OPERATION: The OPA2673 provides the high output current and
340MHz (G = +4V/V) low distortion required in emerging Power Line
Modem driver applications. Operating on a single
UNITY-GAIN STABLE: 600MHz (G = +1) +12V supply, the OPA2673 consumes a low 16mA/ch
HIGH OUTPUT CURRENT: 700mA quiescent current to deliver a very high 700mA output
OUTPUT VOLTAGE SWING: 9.8VPP current. This output current supports even the most
demanding Power Line Modem requirements with
HIGH SLEW RATE: 3000V/msgreater than 460mA minimum output current (+25°C
LOW SUPPLY CURRENT: 16mA/ch minimum value) with low harmonic distortion.
OVERTEMPERATURE PROTECTION CIRCUIT Power control features are included to allow system
FLEXIBLE POWER CONTROL power consumption to be minimized. Two logic
OUTPUT CURRENT LIMIT 800mA) control lines allow four quiescent power settings: full
power, 75% bias power in applications that are less
ACTIVE OFF-LINE FOR TDMA demanding, 50% bias power cutback for short loops,
and offline with active offline control to present a high
APPLICATIONS impedance even with large signals present at the
POWER LINE MODEMS output pin.
MATCHED I/Q CHANNEL AMPLIFIERS Specified on ±6V supplies (to support +12V
BROADBAND VIDEO LINE DRIVERS operation), the OPA2673 also supports up to +13V
ARB LINE DRIVERS single or ±6.5V dual supplies. Video applications
HIGH CAP LOAD DRIVERS benefit from a very high output current to drive up to
10 parallel video loads (15) with < 0.1%/0.1° dG/dΦ
RELATED PRODUCTS nonlinearity.
SINGLES DUALS TRIPLES NOTES
Single +12V
OPA691 OPA2691 OPA3691 Capable
THS6042 ±15V Capable
Single +12V
OPA2677 Capable
OPA2674 Single +12V
Capable,
Output Current
Limit
space
space
Single-Supply Line Driver
1
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.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2008–2010, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
NC(1)
-INA
+INA
GND
NC(1)
-INB
+INB
A1
OUTA
NC(1)
+VS
OUTB
1
2
3
4
12
11
10
9
16
15
14
13
NC(1)
NC(1)
-VS
A0
5
6
7
8
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
PACKAGE/ORDERING INFORMATION(1)
SPECIFIED
PACKAGE- PACKAGE TEMPERATURE PACKAGE ORDERING TRANSPORT MEDIA,
PRODUCT LEAD DESIGNATOR RANGE MARKING NUMBER QUANTITY
OPA2673IRGVT Tape and Reel, 250
OPA2673 QFN-16 RGV –40°C to +85°C OPA2673 OPA2673IRGVR Tape and Reel, 2500
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
ABSOLUTE MAXIMUM RATINGS(1)
Over operating free-air temperature range (unless otherwise noted).
PARAMETER OPA2673 UNIT
Power supply ±6.5 VDC
Internal power dissipation See Thermal Characteristics
Differential input voltage ±2 V
Input common-mode voltage range ±VSV
Storage temperature range: RGV package –65 to +125 °C
Junction temperature, TJ+150 °C
Continuous operating junction temperature +139 °C
Human body model (HBM) 2000 V
ESD Charge device model (CDM) 1500 V
rating: Machine model (MM) 200 V
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated is not implied. Exposure to
absolute-maximum-rated conditions for extended periods may affect device reliability.
PIN CONFIGURATION
RGV PACKAGE
QFN-16
(TOP VIEW)
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OPA2673
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SBOS382F JUNE 2008REVISED MAY 2010
ELECTRICAL CHARACTERISTICS: VS= ±6V
At TA= +25°C, A0 = A1 = 0 (full power), G = +4V/V, RF= 402, and RL= 100, unless otherwise noted. See Figure 76 for ac
performance only. Single channel specifications, except where noted. OPA2673IRGV
MIN/MAX OVER
TYP TEMPERATURE
0°C to –40°C to MIN/ TEST
PARAMETER CONDITIONS +25°C +25°C(2) 70°C(3) +85°C(3) UNIT MAX LEVEL(1)
AC PERFORMANCE
Small-signal bandwidth G = +1V/V, RF= 511, VO= 500mVPP 600 MHz typ C
G = +2V/V, RF= 475, VO= 500mVPP 450 MHz typ C
G = +4V/V, RF= 402, VO= 500mVPP 340 270 265 260 MHz min B
G = +8V/V, RF= 250, VO= 500mVPP 360 270 265 260 MHz min B
Peaking at a gain of +1V/V G = +1V/V, RF= 5112 dB typ C
Bandwidth for 0.1dB flatness G = +4V/V, VO= 500mVPP 50 MHz typ C
Large-signal bandwidth G = +4V/V, VO= 5VPP 300 MHz typ C
Slew rate G = +4V/V, 5V step 3000 2600 2400 2300 V/ms min B
Rise-and-fall time G = +4V/V, 2V step 1.2 ns typ C
Harmonic distortion G = +4V/V, VO= 2VPP, 10MHz,
RL= 50
2nd harmonic A1 = 0, A0 = 0, full bias –67 –61 –60 –59 dBc max B
A1 = 0, A0 = 1, 75% bias –70 –60 –59 –58 dBc max B
A1 = 1, A0 = 0, 50% bias –69 dBc typ C
3rd harmonic A1 = 0, A0 = 0, full bias –80 –73 –72 –70 dBc max B
A1 = 0, A0 = 1, 75% bias –75 –68 –67 –66 dBc max B
A1 = 1, A0 = 0, 50% bias –68 dBc typ C
G = +4V/V, VO= 2VPP, 20MHz,
RL= 50
2nd harmonic A1 = 0, A0 = 0, full bias -68 –62 –61 –60 dBc max B
A1 = 0, A0 = 1, 75% bias -67 –60 –59 –58 dBc max B
A1 = 1, A0 = 0, 50% bias -65 dBc typ C
3rd harmonic A1 = 0, A0 = 0, full bias -72 –63 –62 –61 dBc max B
A1 = 0, A0 = 1, 75% bias -66 –60 –53 –58 dBc max B
A1 = 1, A0 = 0, 50% bias -60 dBc typ C
Input voltage noise f > 1MHz 2.4 2.8 3.2 3.6 nV/Hz max B
Noninverting input current noise f > 1MHz 5.2 5.8 5.3 6.0 pA/Hz max B
Inverting input current noise f > 1MHz 35 40 42 43 pA/Hz max B
Differential gain error NTSC, RL= 1500.03 % typ C
NTSC, RL= 37.50.05 % typ C
Differential phase error NTSC, RL= 1500.01 degrees typ C
NTSC, RL= 37.50.04 degrees typ C
Channel-to-channel crosstalk (QFN-16) f = 5MHz, Input-referred –92 dBc typ C
DC PERFORMANCE(4)
Open-loop transimpedance gain (ZOL) Differential, VO= 0V, RL= 10090 60 56 55 kmin A
Input offset voltage, full bias VCM = 0V ±2 ±7 ±8 ±9 mV max A
Average offset drift, full bias VCM = 0V ±25 ±30 mV/°C max B
Input offset voltage matching, full bias VCM = 0V ±0.5 ±2 ±2.5 ±2.5 mV max A
Input offset voltage, 75% bias VCM = 0V ±2 ±7 ±8 ±9 mV max B
Input offset voltage, 50% bias VCM = 0V ±2 ±7 ±8 ±9 mV max B
(1) Test levels: (A) 100% tested at +25°C. Over temperature limits set by characterization and simulation. (B) Limits set by characterization
and simulation. (C) Typical value only for information.
(2) Junction temperature = ambient for +25°C tested specifications.
(3) Junction temperature = ambient at low temperature limit; junction temperature = ambient +18°C at high temperature limit for over
temperature specifications.
(4) Current is considered positive-out-of node. VCM is the input common-mode voltage.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 3
Product Folder Link(s): OPA2673
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
ELECTRICAL CHARACTERISTICS: VS= ±6V (continued)
At TA= +25°C, A0 = A1 = 0 (full power), G = +4V/V, RF= 402, and RL= 100, unless otherwise noted. See
Figure 76 for ac performance only. Single channel specifications, except where noted.
OPA2673IRGV
MIN/MAX OVER
TYP TEMPERATURE
0°C to –40°C to MIN/ TEST
PARAMETER CONDITIONS +25°C +25°C(2) 70°C(3) +85°C(3) UNIT MAX LEVEL(1)
DC PERFORMANCE (continued)
Noninverting input bias current VCM = 0V ±5 ±25 ±27 ±28 mA max A
Noninverting input bias current drift VCM = 0V ±45 ±47 mA/°C max B
Noninverting input bias current matching VCM = 0V ±0.5 ±5 ±6 ±7 mA max A
Inverting input bias current VCM = 0V ±6 ±48 ±52 ±55 mA max A
Inverting input bias current drift VCM = 0V ±90 ±110 mA/°C max B
Inverting input bias current matching VCM = 0V ±6 ±25 ±30 ±30 mA max A
INPUT(5)
Common-mode input range(6) ±3.6 ±3.5 ±3.3 ±3.2 V min A
Common-mode rejection ratio VCM = 0V, Input-referred 56 50 48 47 dB min A
Noninverting input impedance 1.5 || M|| pF typ C
1.5
Inverting input resistance Open-loop 32 16 min B
Inverting input resistance Open-loop 32 40 max B
Shutdown isolation G = +4V/V, f = 1MHz, A1= A0= 1 85 dB typ C
OUTPUT
Voltage output swing No load ±4.9 ±4.8 ±4.75 ±4.7 V min A
100load ±4.8 ±4.75 ±4.7 ±4.65 V min B
25load ±4.7 ±4.5 ±4.45 ±4.4 V min A
Output current at full power (peak) RL= 4, A1 = 0, A0 = 0 ±700 ±460 ±440 ±425 mA min A
Output current at 75% bias (peak) RL= 4, A1 = 0, A0 = 1 ±500 ±350 ±325 ±300 mA min A
Output current at 50% bias (peak) RL= 4, A1 = 1, A0 = 0 ±180 ±120 ±115 ±110 mA min A
Short-cIrcuit current VO= 0V ±800 mA typ C
Closed-loop output impedance at full power G = +4V/V, f 100kHz, A1 = 0, A0 = 0 0.01 typ C
Closed-loop output impedance at 75% bias G = +4V/V, f 100kHz, A1 = 0, A0 = 1 0.01 typ C
Closed-loop output impedance at 50% bias G = +4V/V, f 100kHz, A1 = 1, A0 = 0 0.01 typ C
Output impedance at shutdown 25 || 4 k|| pF typ C
Output switching glitch Inputs at GND ±20 mV typ C
POWER CONTROL
Maximum logic 0 A1, A0, VS= ±6V 0.8 0.8 0.8 V max A
Minimum logic 1 A1, A0, VS= ±6V 22 2 V min A
Logic input current A0, A1 = 0, each line 6 89 10 mA max A
A0, A1 = 1, each line –50 –110 –125 150 mA min A
(5) Current is considered positive-out-of node. VCM is the input common-mode voltage.
(6) Tested < 3dB below minimum CMRR specifications at ±CMIR limits.
4Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
ELECTRICAL CHARACTERISTICS: VS= ±6V (continued)
At TA= +25°C, A0 = A1 = 0 (full power), G = +4V/V, RF= 402, and RL= 100, unless otherwise noted. See
Figure 76 for ac performance only. Single channel specifications, except where noted.
OPA2673IRGV
MIN/MAX OVER
TYP TEMPERATURE
0°C to –40°C to MIN/ TEST
PARAMETER CONDITIONS +25°C +25°C(2) 70°C(3) +85°C(3) UNIT MAX LEVEL(1)
POWER SUPPLY
Specified operating voltage ±6 V typ C
Maximum operating voltage ±6.5 ±6.5 ±6.5 V max A
Minimum operating voltage (dual supply) ±3.5 V typ C
Minimum operating voltage (single supply) +5.75 V typ C
Maximum quiescent current at full power VS= ±6V, Total both channels, 32 38 40 42 mA max A
A1 = 0, A0 = 0
Minimum quiescent current at full power VS= ±6V, Total both channels, 32 26 25 24 mA min A
A1 = 0, A0 = 0
Supply current at 75% bias VS= ±6V, Total both channels, 24 29 31 33 mA max A
A1 = 0, A0 = 1
Supply current at 50% bias VS= ±6V, Total both channels, 16 19 20 21 mA max A
A1 = 1, A0 = 0
Supply current (off-line) VS= ±6V, Total both channels, 5.5 77.5 8 mA max A
A1 = 1, A0 = 1
Supply current step time
Power-supply rejection ratio (–PSRR) Input-referred 54 49 48 47 dB min A
THERMAL CHARACTERISTICS
Specified operating temperature range IRGV package –40 to °C typ C
+85
Thermal resistance, qJA Junction-to-ambient
RGV QFN-16 PowerPAD soldered to PCB 45 °C/W typ C
PowerPAD floating(7) 75
(7) PowerPad is physically connected to the negative (-VS) supply for dual-supply configuration or ground (GND) for single-supply
configuration.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 5
Product Folder Link(s): OPA2673
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G=+2V/V
R =475
FW
G=+4V/V
R =402
FW
G=+8V/V
R =250
FW
V =500mV
R =100
O PP
LW
G=+1V/V
R =511
FW
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
0 100 200 300 400 500 600 700 800 900 1000
Frequency(MHz)
50%Bias
75%Bias
FullPower
G=+4V/V
R =100
LW
V =500mV
O PP
3
2
1
0
1
2
3
-
-
-
300
200
100
0
100
200
300
-
-
-
OutputVoltage(V)
OutputVoltage(mV)
Time(10ns/div)
G=+4V/V
R =100
LW
LargeSignal 2.5VP
LeftScale
±
SmallSignal 100mVP
RightScale
±
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
0 100 200 300 400 500 600 700 800 900 1000
Frequency(MHz)
G=+4V/V
R =100
LW
V =2V
O PP
V =5V
O PP
V =1V
O PP
V =8V
O PP
-
-
-
-
-
-
-
-
-
40
45
50
55
60
65
70
75
80
Crosstalk(dB)
1 10 100
Frequency(MHz)
Input-Referred
6
4
2
0
2
4
6
-
-
-
OutputVoltage(V)
-800 -600 -400 -200 0 200 400 600 800
OutputCurrent(mA)
2WInternal
PowerDissipation
SingleChannel
2WInternal
PowerDissipation
SingleChannel
100 LoadLineW
25 LoadLineW
10 LoadLineW
50
LoadLine
W
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V, Full Bias
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE
SMALL-SIGNAL FREQUENCY RESPONSE OVER POWER SETTINGS
Figure 1. Figure 2.
SMALL-SIGNAL AND
LARGE-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL PULSE RESPONSES
Figure 3. Figure 4.
CHANNEL-TO-CHANNEL CROSSTALK OUTPUT VOLTAGE AND CURRENT LIMITATIONS
Figure 5. Figure 6.
6Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
-55
60
65
70
75
80
85
90
95
100
105
-
-
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
0.1 1 10 100
Frequency(MHz)
2ndHarmonic
3rdHarmonic
SingleChannel
G=+4V/V
R =100
V =2V
O PP
LW
60
65
70
75
80
85
90
95
100
105
110
-
-
-
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
f=10MHz
LW
0 2 46 8 10
OutputVoltage(V )
PP
-
-
-
-
-
-
-
65
70
75
80
85
90
95
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G=+4V/V
V =2V
f=10MHz
PPO
-76
78
80
82
84
86
88
90
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
3.0 3.5 4.0 4.5 5.0 5.5 6.0
SupplyVoltage(±V )
S
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
f=10MHz
V =2V
LW
O PP
60
50
40
30
20
10
0
InterceptPoint(+dBm)
010 20 30 40 50 100
Frequency(MHz)
PoweratMatched50 LoadW
9080
70
60
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V, Full Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE
Figure 7. Figure 8.
HARMONIC DISTORTION vs LOAD RESISTANCE HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 9. Figure 10.
TWO-TONE, THIRD-ORDER INTERMODULATION
HARMONIC DISTORTION vs NONINVERTING GAIN INTERCEPT
Figure 11. Figure 12.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 7
Product Folder Link(s): OPA2673
8
6
4
2
0
2
4
6
8
-
-
-
-
InputVoltage(V)
32
24
16
8
0
8
16
24
32
-
-
-
-
OutputVoltage(V)
Time(25ns/div)
G=+4V/V
R =100
LWInput
Output
70
60
50
40
30
20
10
0
Power-SupplyRejectionRatio(dB),
Common-ModeRejectionRatio(dB)
1k 10k 100M
Frequency(Hz)
+PSRR
-PSRR
CMRR
100k 1M 10M
120
100
80
60
40
20
0
TransimpedanceGain(dB )W
10k 100k 1G
Frequency(Hz)
Phase
Gain
1M 10M 100M
0
45
90
135
180
225
270
-
-
-
-
-
-
TransimpedancePhase( )°
10
1
0.1
0.01
0.001
Impedance( )W
10k 100k 10M
Frequency(Hz)
1M
6
5
4
3
2
1
0
VoltageRange(±V)
3.5 4.0 6.0
SupplyVoltage( V)±
4.5
PositiveandNegativeOutputVoltageSwing
PositiveandNegativeCommon-ModeInputVoltage
5.0 5.5
100k
10k
1k
100
Impedance( )W
10k 100k 10M
Frequency(Hz)
1M
Open-Loop
Closed-Loop(R =402 ,G=+4V/V)W
F
Single-Ended
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V, Full Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
OVERDRIVE RECOVERY CMRR AND PSRR vs FREQUENCY
Figure 13. Figure 14.
OPEN-LOOP TRANSIMPEDANCE GAIN AND PHASE CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY
Figure 15. Figure 16.
COMMON-MODE INPUT VOLTAGE RANGE
ACTIVE OFF-LINE IMPEDANCE vs FREQUENCY AND OUTPUT SWING vs SUPPLY VOLTAGE
Figure 17. Figure 18.
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4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0.5-
InputOffsetVoltage(mV),
NoninvertingInputBiasCurrent( A)m
-50 -25 125
Temperature( C)°
0
InvertingBiasCurrent
NoninvertingBiasCurrent
InputOffsetVoltage
100755025
17.5
18.0
18.5
19.0
19.5
20.0
20.5
21.0
21.5
22.0
-
-
-
-
-
-
-
-
-
-
InvertingInputBiasCurrent( A)m
8
7
6
5
4
3
2
1
0
dG,d (%/ )f °
1 2 4
Numberof150 LoadsW
3
d ,PositiveVideof
d ,NegativeVideof
dG,PositiveVideo
dG,NegativeVideo
G=+2V/V
R =475
V = 6V
F
S
W
±
600
580
560
540
520
500
480
460
440
420
400
OutputCurrent(mA)
-50 -25 125
Temperature( C)°
0
SupplyCurrent
SinkingOutputCurrent
SourcingOutputCurrent
100755025
31.0
30.8
30.6
30.4
30.2
30.0
29.8
29.6
28.4
29.2
29.0
SupplyCurrent(mA)
100
10
1
VoltageNoiseDensity(nV/ ),
CurrentNoiseDensity(pA/ )
Ö
Ö
Hz
Hz
100 1k 10M
Frequency(Hz)
InvertingCurrentNoise(35pA/ )ÖHz
VoltageNoise(2.4nV/ )ÖHz
NoninvertingCurrentNoise(5.2pA/ )ÖHz
1M100k10k
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V, Full Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
COMPOSITE VIDEO (dG/df) TYPICAL DC DRIFT OVER TEMPERATURE
Figure 19. Figure 20.
SUPPLY AND OUTPUT CURRENT vs TEMPERATURE INPUT VOLTAGE AND CURRENT NOISE DENSITY
Figure 21. Figure 22.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 9
Product Folder Link(s): OPA2673
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G =
V/
DIFF
+2 V
G =+4V/V
DIFF
G = V/
DIFF +8 V
G =+1V/V
V =500mV
R =100 Differential
CM
O PP
LW
G = V/
DIFF +1 V
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
0 100 200 300 400 500 600 700
Frequency(MHz)
G =+4V/V
G =+1V/V
R =100 Differential
DIFF
O PP
CM
LW
V =500mV
50%Bias
75%Bias
FullBias
5
4
3
2
1
0
1
2
3
4
5
-
-
-
-
-
OutputVoltage(V)
Time(10ns/div)
Small-Signal 0.5V
RightScale
P
±
Large-Signal 4V
LeftScale
P
±
1.0
0.8
0.6
0.4
0.2
0
0.2
0.4
0.6
0.8
1.0
-
-
-
-
-
OutputVoltage(V)
20
10
1
R ( )W
S
1 10 100 1000
Capacitance(pF)
15
12
9
6
3
0
Gain(dB)
10M 100M 500M
Frequency(Hz)
C =
L
22pF
C =
L47pF
C =
L10pF
C =
L100pF
RS
RS
OPA2673
OPA2673
CL
1k
(optional)
W
VIN VOUT
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V Differential, Full Bias
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE
SMALL-SIGNAL FREQUENCY RESPONSE OVER POWER SETTING
Figure 23. Figure 24.
SMALL-SIGNAL AND
LARGE-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL PULSE RESPONSES
Figure 25. Figure 26.
DIFFERENTIAL RSvs CAPACITIVE LOAD FREQUENCY RESPONSE vs CAPACITIVE LOAD
Figure 27. Figure 28.
10 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
60
70
80
90
100
110
-
-
-
-
-
-
HarmonicDistortion(dBc)
0.1 1 10 100
Frequency(MHz)
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
R =100 Differential
V =2V
DIFF
CM
L
O PP
W
60
65
70
75
80
85
90
95
100
105
110
-
-
-
-
-
-
-
-
-
-
-
-
55
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
0 2 46 8 10
OutputVoltage(V )
PP
G =+4V/V
G =+1V/V
R =100 Differential
f=10MHz
DIFF
CM
LW
-
-
-
-
-
-
-
75
80
85
90
95
100
105
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
V =2V
f=10MHz
DIFF
PP
CM
O
-84
86
88
90
92
94
96
-
-
-
-
-
-
HarmonicDistortion(dBc)
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
SupplyVoltage( V )
S
±
3rdHarmonic
2ndHarmonic
G =+4V/V
G =+1V/V
R =100 Differential
f=10MHz
V =2V
DIFF
L
O
CM
PP
W
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V Differential, Full Bias (continued)
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE
Figure 29. Figure 30.
HARMONIC DISTORTION vs LOAD RESISTANCE HARMONIC DISTORTION vs NONINVERTING GAIN
Figure 31. Figure 32.
HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 33.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 11
Product Folder Link(s): OPA2673
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G= V/
R =475
+2 V
FW
G=+4 V
R =402
V/
FW
G= V/
R =250
+8 V
FW
V =500mV
R =100
O PP
LW
G=
R =511
+1V/V
FW
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
0 100 200 300 400 500 600 700 800 900
Frequency(MHz)
G=+4V/V
R =100
LW
V =1V
O PP
V =5V
O PP
V =2V
O PP
V =8V
O PP
3
2
1
0
1
2
3
-
-
-
300
200
100
0
100
200
300
-
-
-
OutputVoltage(V)
OutputVoltage(mV)
Time(10ns/div)
G=+4V/V
R =100
LW
LargeSignal 2.5VP
LeftScale
±
SmallSignal 100mVP
RightScale
±
8
6
4
2
0
2
4
6
8
-
-
-
-
InputVoltage(V)
32
24
16
8
0
8
16
24
32
-
-
-
-
OutputVoltage(V)
Time(25ns/div)
G=+4V/V
R =100
LW
Input
Output
500
480
460
440
420
400
380
360
340
320
300
OutputCurrent(mA)
-50 -25 125
Temperature( C)°
0
SupplyCurrent
SinkingOutputCurrent
SourcingOutputCurrent
100755025
24.50
24.25
24.00
23.75
23.50
23.25
23.00
22.75
22.50
22.25
22.00
SupplyCurrent(mA)
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
-
-
-
-
-
-
-
-
-
dG,d (%/ )f °
1 2 4
Numberof150 LoadsW
3
d ,PositiveVideof
d NegativeVideof,
dG,PositiveVideo
dG,NegativeVideo
G=+2V/V
R =475
V = 6V
F
S
W
±
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V, 75% Bias
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL FREQUENCY RESPONSE
Figure 34. Figure 35.
SMALL-SIGNAL AND
LARGE-SIGNAL PULSE RESPONSES OVERDRIVE RECOVERY
Figure 36. Figure 37.
COMPOSITE VIDEO (dG/df) SUPPLY AND OUTPUT CURRENT vs TEMPERATURE
Figure 38. Figure 39.
12 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
-55
60
65
70
75
80
85
90
95
100
105
-
-
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
0.1 1 10 100
Frequency(MHz)
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
V =2V
O PP
LW
60
65
70
75
80
85
90
95
100
105
-
-
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
f=10MHz
LW
0 2 46 8 10
OutputVoltage(V )
PP
-
-
-
-
-
-
-
65
70
75
80
85
90
95
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G=+4V/V
V =2V
f=10MHz
PPO
-74
76
78
80
82
84
86
-
-
-
-
-
-
HarmonicDistortion(dBc)
3.0 3.5 4.0 4.5 5.0 5.5 6.0
SupplyVoltage( V )±S
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
f=10MHz,V =2V
L
O PP
W
60
50
40
30
20
10
0
InterceptPoint(+dBm)
010 20 30 40 50 100
Frequency(MHz)
PoweratMatched50 LoadW
9080
70
60
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V, 75% Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE
Figure 40. Figure 41.
HARMONIC DISTORTION vs LOAD RESISTANCE HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 42. Figure 43.
TWO-TONE, THIRD-ORDER INTERMODULATION
HARMONIC DISTORTION vs NONINVERTING GAIN INTERCEPT
Figure 44. Figure 45.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Link(s): OPA2673
10
1
0.1
0.01
0.001
Impedance( )W
10k 100k 10M
Frequency(Hz)
1M
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V, 75% Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY
Figure 46.
14 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
3
0
3
6
9
12
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G =
V/
DIFF
+2 V
G =+4 V
DIFF V/
G = V/
DIFF +8 V
G =+1V/V
V =500mV
R =100 Differential
CM
O PP
LW
G =
DIFF +1V/V
5
4
3
2
1
0
1
2
3
4
5
-
-
-
-
-
OutputVoltage(V)
Time(10ns/div)
Small-Signal 0.5V
RightScale
P
±
Large-Signal 4V
LeftScale
P
±
1.0
0.8
0.6
0.4
0.2
0
0.2
0.4
0.6
0.8
1.0
-
-
-
-
-
OutputVoltage(V)
-50
60
70
80
90
100
110
-
-
-
-
-
-
HarmonicDistortion(dBc)
100k 1M 10M 100M
Frequency(Hz)
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
R =100 Differential
V =2V
DIFF
CM
L
O PP
W
60
70
80
90
100
110
-
-
-
-
-
-
-
50
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
0 2 46 8 10
OutputVoltage(V )
PP
G =+4V/V
G =+1V/V
R =100 Differential
f=10MHz
DIFF
CM
LW
-
-
-
-
-
-
-
-
-
-
60
65
70
75
80
85
90
95
100
105
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
V =2V
f=10MHz
DIFF
PP
CM
O
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V Differential, 75% Bias
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL FREQUENCY RESPONSE
Figure 47. Figure 48.
SMALL-SIGNAL AND
LARGE-SIGNAL PULSE RESPONSES HARMONIC DISTORTION vs FREQUENCY
Figure 49. Figure 50.
HARMONIC DISTORTION vs OUTPUT VOLTAGE HARMONIC DISTORTION vs LOAD RESISTANCE
Figure 51. Figure 52.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 15
Product Folder Link(s): OPA2673
-74
76
78
80
82
84
86
88
90
92
94
-
-
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
2.5 3.5 4.0 4.5 5.0 5.5 6.0
SupplyVoltage( V )±S
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
R =100 Differential
f=10MHz
V =2V
DIFF
CM
L
O PP
W
3.0
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V Differential, 75% Bias (continued)
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
HARMONIC DISTORTION vs NONINVERTING GAIN HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 53. Figure 54.
16 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
6
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G=
R =475
+2V/V
FW
G=+4 V
R =402
V/
FW
G= V/
R =250
+8 V
FW
V =500mV
R =100
O PP
LW
G= V/
R =511
+1 V
FW
3
2
1
0
1
2
3
-
-
-
300
200
100
0
100
200
300
-
-
-
OutputVoltage(V)
OutputVoltage(mV)
Time(10ns/div)
G=+4V/V
R =100
LW
LargeSignal 2.5VP
LeftScale
±
SmallSignal 100mVP
RightScale
±
8
6
4
2
0
2
4
6
8
-
-
-
-
InputVoltage(V)
32
24
16
8
0
8
16
24
32
-
-
-
-
OutputVoltage(V)
Time(25ns/div)
G=+4V/V
R =100
LW
Input
Output
240
220
200
180
160
140
120
100
OutputCurrent(mA)
-50 -25 125
Temperature( C)°
0
SupplyCurrent
SinkingOutputCurrent
SourcingOutputCurrent
100755025
15.0
14.8
14.6
14.4
14.2
14.0
13.8
13.6
SupplyCurrent(mA)
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
-
-
-
-
-
-
-
-
-
-
dG,d (%/ )f °
1 2 4
Numberof150 LoadsW
3
d ,PositiveVideof
d ,NegativeVideof
dG,PositiveVideo
dG,NegativeVideo
G=+2V/V
R =475
V = 6V
F
S
W
±
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V, 50% Bias
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL FREQUENCY RESPONSE
Figure 55. Figure 56.
SMALL-SIGNAL AND
LARGE-SIGNAL PULSE RESPONSES OVERDRIVE RECOVERY
Figure 57. Figure 58.
COMPOSITE VIDEO (dG/df) SUPPLY AND OUTPUT CURRENT vs TEMPERATURE
Figure 59. Figure 60.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 17
Product Folder Link(s): OPA2673
-
-
40
50
60
70
80
90
100
110
-
-
-
-
-
-
HarmonicDistortion(dBc)
100k 1M 10M 100M
Frequency(Hz)
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
V =2V
O PP
LW
55
60
65
70
75
80
85
90
-
-
-
-
-
-
-
-
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
G=+4V/V
R =100
f=10MHz
LW
0 2 46 8 10
OutputVoltage(V )
PP
-
-
-
-
-
-
-
65
70
75
80
85
90
95
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G=+4V/V
V =2V
f=10MHz
PPO
60
50
40
30
20
10
0
InterceptPoint(+dBm)
010 20 30 40 50 100
Frequency(MHz)
PoweratMatched50 LoadW
9080
70
60
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V, 50% Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE
Figure 61. Figure 62.
HARMONIC DISTORTION vs LOAD RESISTANCE HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 63. Figure 64.
TWO-TONE, THIRD-ORDER INTERMODULATION
HARMONIC DISTORTION vs NONINVERTING GAIN INTERCEPT
Figure 65. Figure 66.
18 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
10
1
0.1
0.01
0.001
Impedance( )W
10k 100k 10M
Frequency(Hz)
1M
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V, 50% Bias (continued)
At TA= +25°C, G = +4V/V, RF= 402, and RL= 100, unless otherwise specified.
CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY
Figure 67.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 19
Product Folder Link(s): OPA2673
3
0
3
6
9
12
15
18
-
-
-
-
-
-
NormalizedGain(dB)
10M 100M 1G
Frequency(Hz)
G =
V/
DIFF
+2 V
G =+4V/V
DIFF
G = V/
DIFF +8 V
G =+1V/V
V =500mV
R =100 Differential
CM
O PP
LW
G = V/
DIFF +1 V
5
4
3
2
1
0
1
2
3
4
5
-
-
-
-
-
OutputVoltage(V)
Time(10ns/div)
Small-Signal 0.5V
RightScale
P
±
Large-Signal 4V
LeftScale
P
±
1.0
0.8
0.6
0.4
0.2
0
0.2
0.4
0.6
0.8
1.0
-
-
-
-
-
OutputVoltage(V)
-45
55
65
75
85
95
105
-
-
-
-
-
-
HarmonicDistortion(dBc)
100k 1M 10M 100M
Frequency(Hz)
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
R =100 Differential
V =2V
DIFF
CM
L
O PP
W
65
70
75
80
85
90
95
100
-
-
-
-
-
-
-
-
-
60
HarmonicDistortion(dBc)
2ndHarmonic
3rdHarmonic
0 2 46 8 10
OutputVoltage(V )
PP
G =+4V/V,
G =+1V/V,f=10MHz
DIFF
CM
R =100 Differential
LW
-
-
-
-
-
-
-
-
-
-
-
60
65
70
75
80
85
90
95
100
105
110
HarmonicDistortion(dBc)
10 100 1k
Resistance( )W
2ndHarmonic
3rdHarmonic
G =+4V/V
G =+1V/V
V =2V
f=10MHz
DIFF
PP
CM
O
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
TYPICAL CHARACTERISTICS: VS= ±6V Differential, 50% Bias
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
SMALL-SIGNAL FREQUENCY RESPONSE LARGE-SIGNAL FREQUENCY RESPONSE
Figure 68. Figure 69.
SMALL-SIGNAL AND
LARGE-SIGNAL PULSE RESPONSES HARMONIC DISTORTION vs FREQUENCY
Figure 70. Figure 71.
HARMONIC DISTORTION vs OUTPUT VOLTAGE HARMONIC DISTORTION vs LOAD RESISTANCE
Figure 72. Figure 73.
20 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
-
-
65
70
75
80
85
90
95
-
-
-
-
-
HarmonicDistortion(dBc)
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
SupplyVoltage( V )
S
±
2ndHarmonic
3rdHarmonic
G =+4V/V
G +1V/V
R =100 Differential
f=10MHz
V =2V
DIFF
O PP
CM
LW
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TYPICAL CHARACTERISTICS: VS= ±6V Differential, 50% Bias (continued)
At TA= +25°C, RF= 511, RL= 100Differential, GDIFF = +4V/V, and GCM = +1V/V, unless otherwise specified.
HARMONIC DISTORTION vs NONINVERTING GAIN HARMONIC DISTORTION vs SUPPLY VOLTAGE
Figure 74. Figure 75.
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 21
Product Folder Link(s): OPA2673
2kW
82.5W
75 CableW
RG-59
82.5W
75W
475W402W
Video1
+5V
+5V
-5V
1/2
OPA2673
1/2
OPA2673
2kW
75W
475W402W
Video2
-5V
+5V
DIS
DIS
Power-supply
decouplingnotshown.
VDIS
1/2
OPA2673
+6V
+
-6V
50 LoadW
50W
50WVO
VI
50 SourceW
RG
133W
RF
402W
+
6.8 Fm
0.1 Fm6.8 Fm
0.1 Fm
+VS
-VS
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
APPLICATION INFORMATION
WIDEBAND VIDEO MULTIPLEXING
WIDEBAND CURRENT-FEEDBACK
OPERATION One common application for video speed amplifiers
that include a disable pin is to wire multiple amplifier
The OPA2673 gives the exceptional ac performance outputs together, then select one of several possible
of a wideband current-feedback op amp with a highly video inputs to source onto a single line. This simple
linear, high-power output stage. Requiring 16mA/ch wired-OR video multiplexer can be easily
quiescent current, the OPA2673 swings to within 1.1V implemented using the OPA2673, as Figure 77
of either supply rail and delivers in excess of 460mA illustrates.
at room temperature. This low output headroom
requirement, along with supply voltage independent
biasing, gives remarkable dual 6V) supply
operation. The OPA2673 delivers greater than
450MHz bandwidth driving a 2VPP output into 100
on a single +12V supply. Previous boosted output
stage amplifiers typically suffer from very poor
crossover distortion as the output current goes
through zero. The OPA2673 achieves a comparable
power gain with much better linearity. The primary
advantage of a current-feedback op amp over a
voltage-feedback op amp is that ac performance
(bandwidth and distortion) is relatively independent of
signal gain. Figure 76 shows the dc-coupled, gain of
+4V/V, dual power-supply circuit configuration used
as the basis of the ±6V Electrical Characteristics and
Typical Characteristics. For test purposes, the input
impedance is set to 50with a resistor to ground and
the output impedance is set to 50with a series
output resistor. Voltage swings reported in the Figure 77. Two-Channel Video Multiplexer
Electrical Characteristics are taken directly at the
input and output pins, while load powers (dBm) are Typically, channel switching is performed either on
defined at a matched 50load. For the circuit of sync or retrace time in the video signal. The two
Figure 76, the total effective load is 100|| 402=inputs are approximately equal at this time. The
80.make-before-break disable characteristic of the
OPA2673 ensures that there is always one amplifier
controlling the line when using a wired-OR circuit
similar to that shown in Figure 77. Because both
inputs may be on for a short period during the
transition between channels, the outputs are
combined through the output impedance matching
resistors (82.5in this case). When one channel is
disabled, its feedback network forms part of the
output impedance and slightly attenuates the signal in
getting out onto the cable. The gain and output
matching resistors have been slightly increased to get
a signal gain of +1V/V at the matched load and
provide a 75output impedance to the cable. The
video multiplexer connection (as shown in Figure 77)
also ensures that the maximum differential voltage
across the inputs of the unselected channel do not
exceed the rated ±1.2V maximum for standard video
signal levels. The active-off line circuitry integrated
Figure 76. DC-Coupled, G = +4V/V, Bipolar within the OPA2673 ensures that the off-channel will
Supply, Specification and Test Circuit stay off independently of the signal amplitude present
at the output.
22 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
12
8
4
0
-4
-8
-12
Frequency(MHz)
20MHz,SECOND-ORDERBUTTERWORTH
LOW-PASSFREQUENCYRESPONSE
0.1 100101
Gain(dB)
600W
20MHz,Second-OrderButterworth
Low-PassFilter
1/2
OPA2673
+10V
Power-supply
decouplingnotshown.
32.3W105W
5kW
5kW51W
VI
0.1 Fm
402W
1/2
OPA2673
4VI
100pF
133W
0.1 Fm
150pF
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
Where two outputs are switched (see Figure 77), the has been adjusted to optimize bandwidth for the
output line is always under the control of one amplifier itself. As the single-supply frequency
amplifier or the other as a result of the response plots show, the OPA2673 in this
make-before-break disable timing. In this case, the configuration gives greater than 400MHz small-signal
switching glitches for two 0V inputs drop to less than bandwidth. The capacitor values were chosen as low
20mV. as possible but adequate to override the parasitic
input capacitance of the amplifier. The resistor values
were slightly adjusted to give the desired filter
HIGH-SPEED ACTIVE FILTERS frequency response while accounting for the
Wideband current-feedback op amps make ideal approximate 1ns propagation delay through each
elements for implementing high-speed active filters channel of the OPA2673.
where the amplifier is used as a fixed gain block
inside a passive RC circuit network. The relatively HIGH-POWER TWISTED-PAIR DRIVER
constant bandwidth versus gain provides low
interaction between the actual filter poles and the A very demanding application for a high-speed
required gain for the amplifier. Figure 78 shows an amplifier is to drive a low load impedance while
example single-supply buffered filter application. In maintaining a high output voltage swing to high
this case, one of the OPA2673 channels is used to frequencies. Using the dual current-feedback op amp
set up the dc operating point and provide impedance OPA2673, an 8VPP output signal swing into a
isolation from the signal source into the second-stage twisted-pair line with a typical impedance of 50can
filter. That stage is set up to implement a 20MHz, be realized. Configured as shown on the front page,
maximally flat Butterworth frequency response and the two amplifiers of the OPA2673 drive the output
provide an ac gain of +4V/V. transformer in a push-pull configuration, thus doubling
the peak-to-peak signal swing at each op amp output
The 51input matching resistor is optional in this to 8VPP. The transformer has a turns ratio of 1.4. The
case. The input signal is ac-coupled to the 5V dc total load seen by the amplifier is 35.
reference voltage developed through the resistor
divider from the +10V power supply. This first stage Line driver applications usually have a high demand
acts as a gain of +1V/V voltage buffer for the signal for transmitting the signal with low distortion.
where the 600feedback resistor is required for Current-feedback amplifiers such as the OPA2673
stability. This first stage easily drives the low input are ideal for delivering low-distortion performance to
resistors required at the input of this high-frequency higher gains. The example shown is set for a
filter. The second stage is set for a dc gain of +1V/V, differential gain of 4V/V. This circuit can deliver the
carrying the 5V operating point through to the output maximum 8VPP signal with over 200MHz bandwidth.
pin, and an ac gain of +4V/V. The feedback resistor
Figure 78. Buffered Single-Supply Active Filter
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 23
Product Folder Link(s): OPA2673
P =10 log´
L(1mW) R´L
VRMS
2
RM
RM
VLPP
nVLPP
RL
±IP
±IP
2VLPP
n
1:n
V =
RMS
10
P
(1mW) R 10´ ´
L
L
V =CrestFactor V =CF V
PRMS RMS
´ ´
V =2 CF V
LP RMS
P´ ´
V =V (V +V ) I (R +R )-
OPP CC 1 2
- ´
P1 2
V =
CC 1 2
P´V +(V +V )+I (R +R )
OPP 1 2
V =2 CF
LPP ´ ´
10
P
(1mW) R 10´ ´
L
L
±I =
P4RM
1
´
2
1
n
2 V´LPP
´
R =
M
ZLINE
2n2
VO
R1
V1
+VCC
R2
V2
IP
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
LINE DRIVER HEADROOM MODEL
The first step in a driver design is to compute the
peak-to-peak output voltage from the target
specifications. This calculation is done using the
following equations:
(1)
With PLpower and VRMS voltage at the load, and RL
load impedance, this calculation gives: Figure 79. Driver Peak Output Model
With the required output voltage and current versus
(2) turns ratio set, an output stage headroom model
(3) allows the required supply voltage versus turns ratio
to be developed.
With VPpeak voltage at the load and the crest factor,
CF: The headroom model (see Figure 80) can be
described with the following set of equations:
(4) First, as available output voltage for each amplifier:
with VLPP: peak-to-peak voltage at the load. (8)
Consolidating Equation 1 through Equation 4 allows
the required peak-to-peak voltage at the load function Or, second, as required single-supply voltage:
of the crest factor, the load impedance, and the (9)
power in the load to be expressed. Thus: The minimum supply voltage for a set of power and
load requirements is given by Equation 9.
(5) Table 1 gives V1, V2, R1, and R2for +12V operation
of the OPA2673.
This VLPP is usually computed for a nominal line
impedance and may be taken as a fixed design
target.
The next step for the driver is to compute the
individual amplifier output voltage and currents as a
function of VPP on the line and transformer turns ratio.
As the turns ratio changes, the minimum allowed
supply voltage also changes. The peak current in the
amplifier is given by:
(6)
With VLPP defined in Equation 5 and RMdefined in
Equation 7.
(7)
The peak current is computed in Figure 79 by noting
that the total load is 4RMand that the peak current is Figure 80. Line Driver Headroom Model
half of the peak-to-peak calculated using VLPP.
Table 1. Line Driver Headroom Model Values
V1R1V2R2
+12V 0.9V 20.9V 2
24 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
RT
+VCC
I =
AVG
IP
CF
P =
OUT CF
IP
´ -
CC
V 2PL
P =I V +
TOT Q´CC CF
IP
´ -
CC
V 2PL
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
TOTAL DRIVER POWER FOR LINE DRIVER DESIGN-IN TOOLS
APPLICATIONS Demonstration Fixture
The total internal power dissipation for the OPA2673
in a line driver application is the sum of the quiescent A printed circuit board (PCB) is available to assist in
power and the output stage power. The OPA2673 the initial evaluation of circuit performance using the
holds a relatively constant quiescent current versus OPA2673 in its QFN package option. This demo
supply voltage—giving a power contribution that is board is offered free of charge as an unpopulated
simply the quiescent current times the supply voltage PCB, delivered with a user’s guide. The summary
used (the supply voltage is greater than the solution information for this fixture is shown in Table 2.
given in Equation 9). The total output stage power
may be computed with reference to Figure 81.Table 2. Demonstration Fixture by Package
ORDERING LITERATURE
PRODUCT PACKAGE NUMBER NUMBER
OPA2673IRGV QFN-16 DEM-OPA-QFN-2A SBOU067
This demonstration fixture can be requested through
the Texas Instruments web site (www.ti.com).
Macromodels and Applications Support
Computer simulation of circuit performance using
SPICE is often useful when analyzing the
performance of analog circuits and systems. This
technique is particularly true for video and RF
amplifier circuits where parasitic capacitance and
inductance can have a major effect on circuit
Figure 81. Output Stage Power Model performance. A SPICE model for the OPA2673 is
available through the TI web site (www.ti.com). This
model does a good job of predicting small-signal ac
The two output stages used to drive the load of and transient performance under a wide variety of
Figure 79 can be seen as an H-Bridge in Figure 81.operating conditions, but does not do as well in
The average current drawn from the supply into this predicting the harmonic distortion or dG/dΦ
H-Bridge and load is the peak current in the load characteristics. This model does not attempt to
given by Equation 6 divided by the crest factor (CF). distinguish between the package types in small-signal
This total power from the supply is then reduced by ac performance, nor does it attempt to simulate
the power in RTto leave the power dissipated internal channel-to-channel coupling.
to the drivers in the four output stage transistors. That
power is simply the target line power used in OPERATING SUGGESTIONS
Equation 7 plus the power lost in the matching
elements (RM). In the examples here, a perfect match Setting Resistor Values to Optimize Bandwidth
is targeted giving the same power in the matching
elements as in the load. The output stage power is A current-feedback op amp such as the OPA2673
then set by Equation 10.can hold an almost constant bandwidth over signal
gain settings with the proper adjustment of the
external resistor values, which are shown in the
(10) Typical Characteristics; the small-signal bandwidth
decreases only slightly with increasing gain. These
The total amplifier power is then: characteristic curves also show that the feedback
resistor is changed for each gain setting. The resistor
values on the inverting side of the circuit for a
(11) current-feedback op amp can be treated as frequency
space response compensation elements, whereas the ratios
set the signal gain.
space
space
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 25
Product Folder Link(s): OPA2673
=
VI
VO
a1+ RG
RF
1+ Z(s)
R +R
F I 1+ RG
RF
=a ´ NG
1+ Z(s)
R +R
F I NG´
VO
RG
VI
RI
Z I(S) ERR
a
RF
IERR
= LoopGain
R +R
F I ´NG
Z(s)
NG=NoiseGain=1+
RG
RF
R =530 NG R-
F´I
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
Figure 82 shows the small-signal frequency response Developing the transfer function for the circuit of
analysis circuit for the OPA2673. Figure 82 gives Equation 13:
(13)
This formula is written in a loop-gain analysis format,
where the errors arising from a non-infinite open-loop
gain are shown in the denominator. If Z(s) is infinite
over all frequencies, the denominator of Equation 13
reduces to 1 and the ideal desired signal gain shown
in the numerator is achieved. The fraction in the
denominator of Equation 13 determines the frequency
response. Equation 14 shows this as the loop-gain
equation:
Figure 82. Current-Feedback Transfer Function (14)
Analysis Circuit If 20log(RF+ NG × RI) is drawn on top of the
open-loop transimpedance plot, the difference
The key elements of this current-feedback op amp between the two would be the loop gain at a given
model are: frequency. Eventually, Z(s) rolls off to equal the
a= buffer gain from the noninverting input to the denominator of Equation 14, at which point the loop
inverting input gain has reduced to 1 (and the curves have
RI= buffer output impedance intersected). This point of equality is where the
IERR = feedback error current signal amplifier closed-loop frequency response given by
Equation 13 starts to roll off, and is exactly analogous
Z(s) = frequency-dependent open-loop to the frequency at which the noise gain equals the
transimpedance gain from IERR to VOopen-loop voltage gain for a voltage-feedback op
amp. The difference here is that the total impedance
in the denominator of Equation 14 may be controlled
(12) somewhat separately from the desired signal gain (or
The buffer gain is typically very close to 1.00V/V and NG). The OPA2673 is internally compensated to give
is normally neglected from signal gain considerations. a maximally flat frequency response for RF= 402at
This gain, however, sets the CMRR for a single op NG = 4V/V on ±6V supplies. Evaluating the
amp differential amplifier configuration. For a buffer denominator of Equation 14 (which is the feedback
gain of a< 1.0, the CMRR = –20 × log(1 a)dB. transimpedance) gives an optimal target of 530. As
the signal gain changes, the contribution of the NG ×
RI, the buffer output impedance, is a critical portion of RIterm in the feedback transimpedance changes, but
the bandwidth control equation. The OPA2673 the total can be held constant by adjusting RF.
inverting output impedance is typically 32.Equation 15 gives an approximate equation for
A current-feedback op amp senses an error current in optimum RF over signal gain:
the inverting node (as opposed to a differential input (15)
error voltage for a voltage-feedback op amp) and
passes this on to the output through an internal As the desired signal gain increases, this equation
frequency-dependent transimpedance gain. The eventually suggests a negative RF. A somewhat
Typical Characteristics show this open-loop subjective limit to this adjustment can also be set by
transimpedance response, which is analogous to the holding RGto a minimum value of 20. Lower values
open-loop voltage gain curve for a voltage-feedback load both the buffer stage at the input and the output
op amp. stage if RFgets too low—actually decreasing the
bandwidth. Figure 83 shows the recommended RF
versus NGfor ±6V operation. The values for RF
versus gain shown here are approximately equal to
the values used to generate the Typical
26 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
600
500
400
300
200
NoiseGain
0 2010 155
FeedbackResistor( )W
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
Characteristics. They differ in that the optimized graph show the zero-voltage output current limit and
values used in the Typical Characteristics are also the zero-current output voltage limit, respectively. The
correcting for board parasitic not considered in the four quadrants give a more detailed view of the
simplified analysis leading to Equation 15. The values OPA2673 output drive capabilities, noting that the
shown in Figure 83 give a good starting point for graph is bounded by a safe operating area of 2W
designs where bandwidth optimization is desired. maximum internal power dissipation (in this case, for
one channel only). Superimposing resistor load lines
onto the plot shows that the OPA2673 can drive ±4V
into 10or ±4.5V into 25without exceeding the
output capabilities or the 2W dissipation limit. A 100
load line (the standard test circuit load) shows the full
±4.8V output swing capability, as stated in the
Electrical Characteristics table. The minimum
specified output voltage and current over temperature
are set by worst-case simulations at the cold
temperature extreme. Only at cold startup do the
output current and voltage decrease to the numbers
shown in the Electrical Characteristics table. As the
output transistors deliver power, the junction
temperatures increase, decreasing the VBEs
(increasing the available output voltage swing), and
increasing the current gains (increasing the available
output current). In steady-state operation, the
Figure 83. Feedback Resistor vs Noise Gain available output voltage and current is always greater
than that shown in the over-temperature
The total impedance going into the inverting input specifications because the output stage junction
may be used to adjust the closed-loop signal temperatures is higher than the minimum specified
bandwidth. Inserting a series resistor between the operating ambient.
inverting input and the summing junction increases
the feedback impedance (the denominator of Driving Capacitive Loads
Equation 14), decreasing the bandwidth. The internal One of the most demanding and yet very common
buffer output impedance for the OPA2673 is slightly load conditions for an op amp is capacitive loading.
influenced by the source impedance coming from of Often, the capacitive load is the input of an
the noninverting input terminal. High-source resistors analog-to-digital converter (ADC)—including
also have the effect of increasing RI, decreasing the additional external capacitance that may be
bandwidth. For those single-supply applications that recommended to improve the ADC linearity. A
develop a midpoint bias at the noninverting input high-speed, high open-loop gain amplifier such as the
through high valued resistors, the decoupling OPA2673 can be very susceptible to decreased
capacitor is essential for power-supply ripple stability and closed-loop response peaking when a
rejection, noninverting input noise current shunting, capacitive load is placed directly on the output pin.
and to minimize the high-frequency value for RIin When the amplifier open-loop output resistance is
Figure 82.considered, this capacitive load introduces an
additional pole in the signal path that can decrease
Output Current and Voltage the phase margin. Several external solutions to this
The OPA2673 provides output voltage and current problem have been suggested.
capabilities that are unsurpassed in a low-cost dual When the primary considerations are frequency
monolithic op amp. Under no-load conditions at response flatness, pulse response fidelity, and/or
+25°C, the output voltage typically swings closer than distortion, the simplest and most effective solution is
1.1V to either supply rail; the tested (+25°C) swing to isolate the capacitive load from the feedback loop
limit is within 1.2V of either rail. Into a 4load (the by inserting a series isolation resistor between the
minimum tested load), it delivers more than ±460mA. amplifier output and the capacitive load. This
The specifications described previously, though approach does not eliminate the pole from the loop
familiar in the industry, consider voltage and current response, but rather shifts it and adds a zero at a
limits separately. In many applications, it is the higher frequency. The additional zero acts to cancel
voltage times current (or V-I product) that is more the phase lag from the capacitive load pole, thus
relevant to circuit operation. Refer to the Output increasing the phase margin and improving stability.
Voltage and Current Limitations plot in the Typical The Typical Characteristics show the Differential RS
Characteristics (Figure 6). The X- and Y-axes of this vs Capacitive Load (Figure 27) and the resulting
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 27
Product Folder Link(s): OPA2673
E =
OE +(I R ) +4kTR
NI BN S S xNG +(I R ) +4kTR NG
BI F F
2 2 2
4kT
RG
RG
RF
RS
1/2
OPA2673
IBI
EO
IBN
4kT=1.6E 20J-
at290 K°
ERS
ENI
Ö4kTRS
Ö4kTRF
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
frequency response at the load. Parasitic capacitive Typical Characteristics show 69dBc difference
loads greater than 2pF can begin to degrade the between the test-tone power and the third-order
performance of the OPA2673. Long PCB traces, intermodulation spurious levels. This exceptional
unmatched cables, and connections to multiple performance improves further when operating at
devices can easily cause this value to be exceeded. lower frequencies.
Always consider this effect carefully, and add the
recommended series resistor as close as possible to Noise Performance
the OPA2673 output pin (see the Board Layout Wideband current-feedback op amps generally have
Guidelines section). a higher output noise than comparable
voltage-feedback op amps. The OPA2673 offers an
Distortion Performance excellent balance between voltage and current noise
The OPA2673 provides good distortion performance terms to achieve low output noise. The inverting
into a 100load on ±6V supplies. Generally, until the current noise (35pA/Hz) is lower than earlier
fundamental signal reaches very high frequency or solutions, whereas the input voltage noise
power levels, the second harmonic dominates the (2.4nV/Hz) is lower than most unity-gain stable,
distortion with a negligible third harmonic component. wideband voltage-feedback op amps. This low input
Focusing then on the second harmonic, increasing voltage noise is achieved at the price of higher
the load impedance improves distortion directly. noninverting input current noise (5.2pA/Hz). As long
Remember that the total load includes the feedback as the ac source impedance from the noninverting
network—in the noninverting configuration (see node is less than 100, this current noise does not
Figure 76), this network is the sum of RF+ RG; in the contribute significantly to the total output noise. The
inverting configuration, it is RF. Also, providing an op amp input voltage noise and the two input current
additional supply decoupling capacitor (0.01mF) noise terms combine to give low output noise under a
between the supply pins (for bipolar operation) wide variety of operating conditions. Figure 84 shows
improves the second-order distortion slightly (3dB to the op amp noise analysis model with all noise terms
6dB). included. In this model, all noise terms are taken to
be noise voltage or current density terms in either
In most op amps, increasing the output voltage swing nV/Hz or pA/Hz.
directly increases harmonic distortion. The Typical
Characteristics show the second harmonic increasing The total output spot noise voltage can be computed
at a little less than the expected 2x rate, whereas the as the square root of the sum of all squared output
third harmonic increases at a little less than the noise voltage contributors. Equation 16 shows the
expected 3x rate. Where the test power doubles, the general form for the output noise voltage using the
difference between it and the second harmonic terms given in Figure 84.
decreases less than the expected 6dB, while the
difference between it and the third harmonic
decreases by less than the expected 12dB. This (16)
factor also shows up in the two-tone, third-order
intermodulation spurious (IM3) response curves. The
third-order spurious levels are extremely low at
low-output power levels. The output stage continues
to hold them low even as the fundamental power
reaches very high levels. As the Typical
Characteristics show, the spurious intermodulation
powers do not increase as predicted by a traditional
intercept model. As the fundamental power level
increases, the dynamic range does not decrease
significantly. For two tones centered at 40MHz, with
10dBm/tone into a matched 50load (that is, 2VPP
for each tone at the load, which requires 8VPP for the
overall two-tone envelope at the output pin), the
Figure 84. Op Amp Noise Analysis Model
28 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
E =
IE +(I xR ) +4kTR
NI BN S S +(I xR ) +4kTR
BI F F
2 2 2
NG
NG2
RG
RF
RS
E2
O
Driver
ERS
EN
IN
II
Ö4kTRS
Ö4kTRF
RF
RS
ERS
EN
II
IN
Ö4kTRS
Ö4kTRG
Ö4kTRF
G =1+
D
2 R´F
RG
E =
O
2E +(I R ) +4kTR
N N S S
´
2 2
2 G´D´
2+2(I R ) +2(4kTR G )
I F F D
2
E =
IE +(I R ) +4kTR
N N S S
´
2 2 4kTRF
GD
RF
GD
2
+22 ´+2 II
V = (NG V ) (I R /2 NG) (I R )
whereNG=noninvertingsignalgain
± ´ ± ´ ´ ± ´
IO(MAX) BN S BI F
OS
= (4 7mV)+(25 A 25 4) (402 48 A)
= 28mV 2.5mV 19.3mV
V = 49.8mV(maxat+25 C)
± ´ m ´ W ´ ± W ´ m
± ± ±
± °
OS
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
Dividing this expression by the noise gain [NG = (1 +
RF/RG)] gives the equivalent input-referred spot noise
voltage at the noninverting input, as shown in
Equation 17.
(17)
Evaluating these two equations for the OPA2673
circuit and component values of Figure 76 gives a
total output spot noise voltage of 18nV/Hz and a
total equivalent input spot noise voltage of 4.5nV/Hz.
This total input-referred spot noise voltage is higher
than the 2.4nV/Hz specification for the op amp
voltage noise alone. This result reflects the noise
added to the output by the inverting current noise
times the feedback resistor. If the feedback resistor is
reduced in high-gain configurations (as suggested
previously), the total input-referred voltage noise
given by Equation 17 approaches only the 2.4nV/Hz
of the op amp. For example, going to a gain of +8V/V
using RF= 250gives a total input-referred noise of
2.8nV/Hz.
Differential Noise Performance
Because the OPA2673 is used as a differential driver
in PLC applications, it is important to analyze the
noise in such a configuration. See Figure 85 for the Figure 85. Differential Op Amp Noise Analysis
op amp noise model for the differential configuration. Model
As a reminder, the differential gain is expressed as:
DC Accuracy and Offset Control
(18) A current-feedback op amp such as the OPA2673
provides exceptional bandwidth in high gains, giving
The output noise voltage can be expressed as shown fast pulse settling but only moderate dc accuracy.
below: The Electrical Characteristics show an input offset
voltage comparable to high-speed, voltage-feedback
amplifiers; however, the two input bias currents are
(19) somewhat higher and are unmatched. While bias
Dividing this expression by the differential noise gain, current cancellation techniques are very effective with
GD= (1 + 2RF/RG), gives the equivalent input-referred most voltage-feedback op amps, they do not
spot noise voltage at the noninverting input, as shown generally reduce the output dc offset for wideband
in Equation 20. current-feedback op amps. Because the two input
bias currents are unrelated in both magnitude and
polarity, matching the input source impedance to
reduce error contribution to the output is ineffective.
Evaluating the configuration of Figure 76, using a
(20) worst-case +25°C input offset voltage and the two
Evaluating this equation for the OPA2673 circuit and input bias currents, gives a worst-case output offset
component values shown on the front page gives a range equal to:
total output spot noise voltage of 72.3nV/Hz and a
total equivalent input spot noise voltage of
18.4nV/Hz.
In order to minimize the noise contributed by IN, it is
recommended to keep the noninverting source
impedance as low as possible. (21)
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 29
Product Folder Link(s): OPA2673
+VS
A0orA1
1.4V
Control
GND
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
Power Control Operation The shutdown feature for the OPA2673 is a
ground-supply referenced, current-controlled
The OPA2673 provides a power control feature that interface. For voltage output logic interfaces, the
may be used to reduce system power. The four on/off voltage levels described in the Electrical
modes of operation for this power control feature are Characteristics apply only for either the ground pin
100% bias, 75% bias, 50% bias, and power RGV package or the –VSpin used for the
shutdown. These four operating modes are set single-supply specifications.
through two logic lines A0 and A1. Table 3 shows the
different modes of operation. THERMAL ANALYSIS
Table 3. Operating Modes As a result of the high output power capability of the
OPA2673, heat-sinking or forced airflow may be
MODE OF required under extreme operating conditions. The
OPERATION A1 A0 maximum desired junction temperature sets the
100% bias 0 0 maximum allowed internal power dissipation,
75% bias 0 1 described below. In no case should the maximum
50% bias 1 0 junction temperature be allowed to exceed +150°C.
Shutdown 1 1 Operating junction temperature (TJ) is given by TA+
PD×qJA. The total internal power dissipation (PD) is
The 100% bias mode is used for normal operating the sum of quiescent power (PDQ) and additional
conditions. The 75% bias mode brings the quiescent power dissipation in the output stage (PDL) to deliver
power to 24mA. The 50% bias mode brings the load power. Quiescent power is the specified no-load
quiescent power to 16mA. The shutdown mode has a supply current times the total supply voltage across
high output impedance as well as the lowest the part. PDL depends on the required output signal
quiescent power (5.5mA). and load; for a grounded resistive load, however, PDL
If the A0 and A1 pins are left unconnected, the is at a maximum when the output is fixed at a voltage
OPA2673 operates normally (100% bias). equal to 1/2 of either supply voltage (for equal bipolar
supplies). Under this condition, PDL = VS2/(4 × RL),
To change the power mode, the control pins (either where RLincludes feedback network loading.
A0 or A1) must be asserted low. This logic control is
referenced to the ground supply, as shown in the Note that it is the power in the output stage and not
simplified circuit of Figure 86.into the load that determines internal power
dissipation.
As a worst-case example, compute the maximum TJ
using an OPA2673 QFN-16 in the circuit of Figure 76
operating at the maximum specified ambient
temperature of +85°C with both outputs driving a
grounded 20load to +2.5V.
PD= 12V × 32mA + 2 × [52/(4 × [20535])]
= 1.03W
Maximum TJ= +85°C + (1.03 × 45°C/W) = 131°C
Although this value is still well below the specified
maximum junction temperature, system, reliability
considerations may require lower tested junction
temperatures.The highest possible internal dissipation
occurs if the load requires current to be forced into
Figure 86. Supply Power Control Circuit the output for positive output voltages, or sourced
from the output for negative output voltages. This
space condition puts a high current through a large internal
drop in the output transistors. The output V-I plot in
space the Typical Characteristics (Figure 6) includes a
boundary for 2W maximum internal power dissipation
under these conditions.
30 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
OPA2673
www.ti.com
SBOS382F JUNE 2008REVISED MAY 2010
BOARD LAYOUT GUIDELINES peaked frequency response. The 402feedback
resistor used in the Typical Characteristics at a gain
Achieving optimum performance with a of +4V/V on ±6V supplies is a good starting point for
high-frequency amplifier such as the OPA2673 design. Note that a 511feedback resistor, rather
requires careful attention to board layout parasitic and than a direct short, is recommended for the unity-gain
external component types. Recommendations that follower application. A current-feedback op amp
optimize performance include: requires a feedback resistor even in the unity-gain
follower configuration to control stability.
a) Minimize parasitic capacitance to any ac ground
for all of the signal I/O pins. Parasitic capacitance on d) Connections to other wideband devices on the
the output and inverting input pins can cause board may be made with short direct traces or
instability; on the noninverting input, it can react with through onboard transmission lines. For short
the source impedance to cause unintentional band connections, consider the trace and the input to the
limiting. To reduce unwanted capacitance, a window next device as a lumped capacitive load. Relatively
around the signal I/O pins should be opened in all of wide traces (50mils to 100mils, or 1,27mm to
the ground and power planes around those pins. 2,54mm) should be used, preferably with ground and
Otherwise, ground and power planes should be power planes opened up around them. Estimate the
unbroken elsewhere on the board. total capacitive load and set RSfrom the plot of
Differential RSvs Capacitive Load (Figure 27). Low
b) Minimize the distance (< 0.25in, or 6,350mm) parasitic capacitive loads (< 5pF) may not need an
from the power-supply pins to high-frequency 0.1mFRSbecause the OPA2673 is nominally compensated
decoupling capacitors. At the device pins, the ground to operate with a 2pF parasitic load. If a long trace is
and power-plane layout should not be in close required, and the 6dB signal loss intrinsic to a
proximity to the signal I/O pins. Avoid narrow power doubly-terminated transmission line is acceptable,
and ground traces to minimize inductance between implement a matched impedance transmission line
the pins and the decoupling capacitors. The using microstrip or stripline techniques (consult an
power-supply connections (on pins 7 and 14 for a ECL design handbook for microstrip and stripline
QFN package) should always be decoupled with layout techniques). A 50environment is normally
these capacitors. An optional supply decoupling not necessary onboard. In fact, a higher impedance
capacitor across the two power supplies (for bipolar environment improves distortion; see the distortion
operation) improves second-harmonic distortion versus load plots. With a characteristic board trace
performance. Larger (2.2mF to 6.8mF) decoupling impedance defined based on board material and
capacitors, effective at a lower frequency, should also trace dimensions, a matching series resistor into the
be used on the main supply pins. These can be trace from the output of the OPA2673 is used, as well
placed somewhat farther from the device and may be as a terminating shunt resistor at the input of the
shared among several devices in the same area of destination device. Remember also that the
the PCB. terminating impedance is the parallel combination of
c) Careful selection and placement of external the shunt resistor and the input impedance of the
components preserve the high-frequency destination device.
performance of the OPA2673. Resistors should be This total effective impedance should be set to match
of a very low reactance type. Surface-mount resistors the trace impedance. The high output voltage and
work best and allow a tighter overall layout. Metal film current capability of the OPA2673 allows multiple
and carbon composition axially-leaded resistors can destination devices to be handled as separate
also provide good high-frequency performance. transmission lines, each with respective series and
Again, keep the leads and PCB trace length as short shunt terminations. If the 6dB attenuation of a
as possible. Never use wire-wound type resistors in a doubly-terminated transmission line is unacceptable,
high-frequency application. Although the output pin a long trace can be series-terminated at the source
and inverting input pin are the most sensitive to end only. Treat the trace as a capacitive load in this
parasitic capacitance, always position the feedback case, and set the series resistor value as shown in
and series output resistor, if any, as close as possible the plot of Differential RSvs Capacitive Load
to the output pin. Other network components, such as (Figure 27). However, this approach does not
noninverting input termination resistors, should also preserve signal integrity as well as a
be placed close to the package. Where double-side doubly-terminated line. If the input impedance of the
component mounting is allowed, place the feedback destination device is low, there is some signal
resistor directly under the package on the other side attenuation because of the voltage divider formed by
of the board between the output and inverting input the series output into the terminating impedance.
pins. The frequency response is primarily determined
by the feedback resistor value as described
previously. Increasing the value reduces the
bandwidth, whereas decreasing it gives a more
Copyright © 2008–2010, Texas Instruments Incorporated Submit Documentation Feedback 31
Product Folder Link(s): OPA2673
External
Pin
+VCC
-VCC
Internal
Circuitry
OPA2673
SBOS382F JUNE 2008REVISED MAY 2010
www.ti.com
e) Socketing a high-speed part such as the These diodes provide moderate protection to input
OPA2673 is not recommended. The additional lead overdrive voltages above the supplies as well. The
length and pin-to-pin capacitance introduced by the protection diodes can typically support 30mA
socket can create an extremely troublesome parasitic continuous current. Where higher currents are
network, which can make it almost impossible to possible (for example, in systems with ±15V supply
achieve a smooth, stable frequency response. Best parts driving into the OPA2673), current-limiting
results are obtained by soldering the OPA2673 series resistors should be added into the two inputs.
directly onto the board. Keep these resistor values as low as possible,
because high values degrade both noise performance
and frequency response.
INPUT AND ESD PROTECTION
The OPA2673 is built using a high-speed
complementary bipolar process. The internal junction
breakdown voltages are relatively low for these very
small geometry devices and are reflected in the
Absolute Maximum Ratings table. All device pins
have limited ESD protection using internal diodes to
the power supplies, as shown in Figure 87.
Figure 87. ESD Steering Diodes
empty for space
empty for space
empty for space
empty for space REVISION HISTORY
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision E (April, 2010) to Revision F Page
Added minimum operating voltage (single supply) parameter ............................................................................................. 5
Changes from Revision D (January, 2010) to Revision E Page
Revised Absolute Maximum Ratings table; deleted lead temperature specification, changed storage temperature
range from –40°C to –65°C .................................................................................................................................................. 2
32 Submit Documentation Feedback Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2673
PACKAGING INFORMATION
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
OPA2673IRGVR ACTIVE VQFN RGV 16 2500 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
OPA2673IRGVRG4 ACTIVE VQFN RGV 16 2500 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
OPA2673IRGVT ACTIVE VQFN RGV 16 250 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
OPA2673IRGVTG4 ACTIVE VQFN RGV 16 250 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
(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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 5-May-2010
Addendum-Page 1
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
OPA2673IRGVR VQFN RGV 16 2500 330.0 12.4 4.25 4.25 1.15 8.0 12.0 Q2
OPA2673IRGVT VQFN RGV 16 250 180.0 12.4 4.25 4.25 1.15 8.0 12.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Jul-2012
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
OPA2673IRGVR VQFN RGV 16 2500 367.0 367.0 35.0
OPA2673IRGVT VQFN RGV 16 250 210.0 185.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Jul-2012
Pack Materials-Page 2
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