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FEATURES Ultrahigh Speed 5,500 V/ s Slew Rate, 4 V Step, G = +2 545 ps Rise Time, 2 V Step, G = +2 Large Signal Bandwidth 440 MHz, G = +2 320 MHz, G = +10 Small Signal Bandwidth (-3 dB) 1 GHz, G = +1 700 MHz, G = +2 Settling Time 10 ns to 0.1%, 2 V Step, G = +2 Low Distortion over Wide Bandwidth SFDR -66 dBc @ 20 MHz, Second Harmonic -75 dBc @ 20 MHz, Third Harmonic Third Order Intercept (3IP) 26 dBm @ 70 MHz, G = +10 Good Video Specifications Gain Flatness 0.1 dB to 75 MHz 0.01% Differential Gain Error, RL = 150 0.01 Differential Phase Error, RL = 150 High Output Drive 175 mA Output Load Drive 10 dBm with -38 dBc SFDR @ 70 MHz, G = +10 Supply Operation +5 V to 5 V Voltage Supply 14 mA (Typ) Supply Current APPLICATIONS Pulse Amplifier IF/RF Gain Stage/Amplifiers High Resolution Video Graphics High Speed Instrumentations CCD Imaging Amplifier
2 1 0
NORMALIZED GAIN (dB)
1 GHz, 5,500 V/ s Low Distortion Amplifier AD8009
FUNCTIONAL BLOCK DIAGRAMS 8-Lead Plastic SOIC (R-8)
NC 1 -IN 2
5-Lead SOT-23 (RT-5)
AD8009
VOUT 1 -VS 2 +IN 3
4 5
AD8009
8 NC 7 +VS 6 OUT 5 NC
+VS
+IN 3 -VS 4 NC = NO CONNECT
-IN
PRODUCT DESCRIPTION
The AD8009 is an ultrahigh speed current feedback amplifier with a phenomenal 5,500 V/s slew rate that results in a rise time of 545 ps, making it ideal as a pulse amplifier. The high slew rate reduces the effect of slew rate limiting and results in the large signal bandwidth of 440 MHz required for high resolution video graphic systems. Signal quality is maintained over a wide bandwidth with worst-case distortion of -40 dBc @ 250 MHz (G = +10, 1 V p-p). For applications with multitone signals, such as IF signal chains, the third order intercept (3IP) of 12 dBm is achieved at the same frequency. This distortion performance coupled with the current feedback architecture make the AD8009 a flexible component for a gain stage amplifier in IF/RF signal chains. The AD8009 is capable of delivering over 175 mA of load current and will drive four back terminated video loads while maintaining low differential gain and phase error of 0.02% and 0.04, respectively. The high drive capability is also reflected in the ability to deliver 10 dBm of output power @ 70 MHz with -38 dBc SFDR. The AD8009 is available in a small SOIC package and will operate over the industrial temperature range -40C to +85C. The AD8009 is also available in an SOT-23-5 and will operate over the commercial temperature range of 0C to 70C.
-30 -40 -50 -60 -70 -80 THIRD 100 LOAD THIRD 150 LOAD G=2 RF = 301 VO = 2V p-p SECOND 100 LOAD SECOND 150 LOAD
G = +2 RF = 301 RL = 150
-1 VO = 2V p-p -2 -3 -4 -5 -6 -7 -8 1 100 10 FREQUENCY RESPONSE (MHz) 1000 G = +10 RF = 200 RL = 100
DISTORTION (dBc)
-90 -100 1
Figure 1. Large Signal Frequency Response; G = +2 and +10
REV. F
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.
10 FREQUENCY RESPONSE (MHz)
70
Figure 2. Distortion vs. Frequency; G = +2
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 (c) 2004 Analog Devices, Inc. All rights reserved.
= V AD8009-SPECIFICATIONSfor(@=T +1,25 C, 226= R = 200 for G = +10; for RT Package: R = 332 G R=
A S F F F
5 V, RL = 100 ; for R Package: RF = 301 for G = +1, +2, for G = +2 and RF = 191 for G = +10, unless otherwise noted.)
Min AD8009AR/JRT Typ Max Unit
Model DYNAMIC PERFORMANCE -3 dB Small Signal Bandwidth, VO = 0.2 V p-p R Package RT Package
Conditions
Large Signal Bandwidth, VO = 2 V p-p Gain Flatness 0.1 dB, VO = 0.2 V p-p Slew Rate Settling Time to 0.1% Rise and Fall Time HARMONIC/NOISE PERFORMANCE Second Harmonic G = +2, VO = 2 V p-p Third Harmonic
G = +1, RF = 301 G = +1, RF = 332 G = +2 G = +10 G = +2 G = +10 G = +2, RL = 150 G = +2, RL = 150 , 4 V Step G = +2, RL = 150 , 2 V Step G = +10, 2 V Step G = +2, RL = 150 , 4 V Step 10 MHz 20 MHz 70 MHz 10 MHz 20 MHz 70 MHz 70 MHz 150 MHz 250 MHz f = 10 MHz f = 10 MHz, +In f = 10 MHz, -In NTSC, G = +2, RL = 150 NTSC, G = +2, RL = 37.5 NTSC, G = +2, RL = 150 NTSC, G = +2, RL = 37.5
480 300 390 235 45 4,500
1,000 845 700 350 440 320 75 5,500 10 25 0.725 -73 -66 -56 -77 -75 -58 26 18 12 1.9 46 41 0.01 0.02 0.01 0.04 2
MHz MHz MHz MHz MHz MHz MHz V/s ns ns ns dBc dBc dBc dBc dBc dBc dBm dBm dBm nV/Hz pA/Hz pA/Hz % % Degrees Degrees mV mV V/C A A A A k k k pF V dB V mA mA 6 16 18 V mA mA dB
Third Order Intercept (3IP) W.R.T. Output, G = +10 Input Voltage Noise Input Current Noise Differential Gain Error Differential Phase Error DC PERFORMANCE Input Offset Voltage
0.03 0.05 0.03 0.08 5 7 150 150
TMIN to TMAX Offset Voltage Drift -Input Bias Current TMIN to TMAX +Input Bias Voltage TMIN to TMAX Open-Loop Transresistance TMIN to TMAX INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio OUTPUT CHARACTERISTICS Output Voltage Swing Output Current Short-Circuit Current POWER SUPPLY Operating Range Quiescent Current Power Supply Rejection Ratio
Specifications subject to change without notice.
90
4 50 75 50 75 250 170 110 8 2.6 3.8 52 3.8 175 330
+Input -Input +Input VCM = 2.5 50
3.7 RL = 10 , PD Package = 0.7 W 150
+5 14 TMIN to TMAX VS = 4 V to 6 V 64 70
-2-
REV. F
AD8009
SPECIFICATIONS R = 200
Model
(@ TA = 25 C, VS = 5 V, RL = 100 for G = +10). F
Conditions
, for R Package: RF = 301
for G = +1, +2,
Min
AD8009AR/JRT Typ Max
Unit
DYNAMIC PERFORMANCE -3 dB Small Signal Bandwidth, VO = 0.2 V p-p
Large Signal Bandwidth, VO = 2 V p-p Gain Flatness 0.1 dB, VO = 0.2 V p-p Slew Rate Settling Time to 0.1% Rise and Fall Time HARMONIC/NOISE PERFORMANCE Second Harmonic G = +2, VO = 2 V p-p Third Harmonic
G = +1, RF = 301 G = +2 G = +10 G = +2 G = +10 G = +2, RL = 150 G = +2, RL = 150 , 4 V Step G = +2, RL = 150 , 2 V Step G = +10, 2 V Step G = +2, RL = 150 , 4 V Step 10 MHz 20 MHz 70 MHz 10 MHz 20 MHz 70 MHz f = 10 MHz f = 10 MHz, +In f = 10 MHz, -In
630 430 300 365 250 65 2,100 10 25 0.725 -74 -67 -48 -76 -72 -44 1.9 46 41 1 50 50 4 150 150
MHz MHz MHz MHz MHz MHz V/s ns ns ns dBc dBc dBc dBc dBc dBc nV/Hz pA/Hz pA/Hz mV A A k pF V dB V mA mA 6 12 V mA dB
Input Voltage Noise Input Current Noise DC PERFORMANCE Input Offset Voltage -Input Bias Current +Input Bias Voltage INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio OUTPUT CHARACTERISTICS Output Voltage Swing Output Current Short-Circuit Current POWER SUPPLY Operating Range Quiescent Current Power Supply Rejection Ratio
Specifications subject to change without notice.
+Input -Input +Input VCM = 1.5 V to 3.5 V 50
110 8 2.6 1.2 to 3.8 52 1.1 to 3.9 175 330
RL = 10 , PD Package = 0.7 W
+5 VS = 4.5 V to 5.5 V 64 10 70
REV. F
-3-
AD8009
ABSOLUTE MAXIMUM RATINGS 1 MAXIMUM POWER DISSIPATION
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.6 V Internal Power Dissipation2 Small Outline Package (R) . . . . . . . . . . . . . . . . . . . . . . . 0.75 W Input Voltage (Common-Mode) . . . . . . . . . . . . . . . . . . . . VS Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . 3.5 V Output Short-Circuit Duration . . . . . . . . . . . . . . . . . . . . . . Observe Power Derating Curves Storage Temperature Range R Package . . . . -65C to +125C Operating Temperature Range (A Grade) . . . -40C to +85C Operating Temperature Range (J Grade) . . . . . . . 0C to 70C Lead Temperature Range (Soldering 10 sec) . . . . . . . . . 300C
NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 Specification is for device in free air: 8-Lead SOIC Package: JA = 155C/W. 5-Lead SOT-23 Package: JA = 240C/W.
The maximum power that can be safely dissipated by the AD8009 is limited by the associated rise in junction temperature. The maximum safe junction temperature for plastic encapsulated devices is determined by the glass transition temperature of the plastic, approximately 150C. Exceeding this limit temporarily may cause a shift in parametric performance due to a change in the stresses exerted on the die by the package. Exceeding a junction temperature of 175C for an extended period can result in device failure. While the AD8009 is internally short circuit protected, this may not be sufficient to guarantee that the maximum junction temperature (150C) is not exceeded under all conditions. To ensure proper operation, it is necessary to observe the maximum power derating curves.
2.0 TJ = 150 C
MAXIMUM POWER DISSIPATION (W)
1.5
8-LEAD SOIC PACKAGE
1.0
0.5
5-LEAD SOT-23 PACKAGE
0 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 AMBIENT TEMPERATURE ( C)
70 80 90
Figure 3. Plot of Maximum Power Dissipation vs. Temperature
ORDERING GUIDE
Model AD8009AR AD8009AR-REEL AD8009AR-REEL7 AD8009ARZ* AD8009ARZ-REEL* AD8009ARZ-REEL7* AD8009JRT-R2 AD8009JRT-REEL AD8009JRT-REEL7 AD8009JRTZ-REEL* AD8009JRTZ-REEL7* AD8009ACHIPS
*Z = Pb-free part.
Temperature Range -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C 0C to 70C 0C to 70C 0C to 70C 0C to 70C 0C to 70C
Package Description 8-Lead SOIC 8-Lead SOIC 8-Lead SOIC 8-Lead SOIC 8-Lead SOIC 8-Lead SOIC 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 Die
Package Option R-8 R-8 R-8 R-8 R-8 R-8 RT-5 RT-5 RT-5 RT-5 RT-5
Branding
HKJ HKJ HKJ HKJ HKJ
CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD8009 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
-4-
REV. F
Typical Performance Characteristics-AD8009
3 2
G = +1, RT
6.2
G = +1, R
6.1 6.0
1
NORMALIZED GAIN (dB)
GAIN FLATNESS (dB)
0 -1 -2 -3 -4 -5 -6 -7 1 10 100 1000 R PACKAGE: RL = 100 VO = 200mV p-p G = +1, +2: RF = 301 G = +10: RF = 200 RT PACKAGE: G = +1: RF = 332 G = +2: RF = 226 G = +10: RF = 191
5.9 5.8 5.7 5.6 5.5 5.4 5.3 5.2 1 10 100 FREQUENCY (MHz) 1000
G = +2 RF = 301 RL = 150 VO = 200mV p-p
G = +2, R AND RT G = +10, R AND RT
FREQUENCY (MHz)
TPC 1. Frequency Response; G = +1, +2, +10, R and RT Packages
TPC 4. Gain Flatness; G = +2
8 7 6 5
0.4
G = +2 RF = 301 RL = 150 VO = 200mV p-p VS = 5V
0.3 0.2
GAIN FLATNESS (dB)
GAIN (dB)
4 3 2 1 0 -1 -2 1
G = +2 RF = 301 RL = 150 VO AS SHOWN
4V p-p 2V p-p
0.1
0
-0.1 -0.2 -0.3
10 100 FREQUENCY (MHz)
1000
1
10
100 FREQUENCY (MHz)
1000
10000
TPC 2. Large Signal Frequency Response; G = +2
TPC 5. Gain Flatness; G = +2; VS = 5 V
8 7 6
-40 C +85 C
22 21 20
5
GAIN (dB)
-40 C
GAIN (dB)
19 18 17 16 15 14 13 12 G = +10 RF = 200 RL = 100 VO AS SHOWN 2V p-p
4 3 2 1 0 -1 -2
1
G = +2 RF = 301 RL = 150 VO = 2V p-p
+85 C
4V p-p
10 100 FREQUENCY (MHz)
1000
1
10 100 FREQUENCY (MHz)
1000
TPC 3. Large Signal Frequency Response vs. Temperature; G = +2
TPC 6. Large Signal Frequency Response; G = +10
REV. F
-5-
AD8009
22 21 20 -40 C +85 C
DISTORTION (dBc)
-35 -40 -45 70MHz -50 250MHz
19 GAIN (dB) 18 17 16 15 14 13 12 1 10 100 FREQUENCY (MHz) G = +10 RF = 200 RL = 100 VO = 2V p-p
-55 -60 -65
5MHz
200
-70 -75
22.1
50 POUT 50
50
-80 -85 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14
1000
POUT (dBm)
TPC 7. Large Signal Frequency Response vs. Temperature; G = +10
-30
TPC 10. Second Harmonic Distortion vs. POUT; (G = +10)
0.02
DIFF GAIN (%)
-40
G=2 RF = 301 VO = 2V p-p SECOND, 100 LOAD SECOND, 150 LOAD
0.01 0.00 -0.01 -0.02
G = +2 RF = 301
RL = 150
-50
DISTORTION (dBc)
-60
RL = 37.5 0 IRE RL = 37.5 100
-80
THIRD, 100 LOAD THIRD, 150 LOAD
DIFF PHASE (Degrees)
-70
0.10 G = +2 0.05 RF = 301 -0.00 RL = 150 -0.05 -0.10 0
-90 -100 1 10 FREQUENCY RESPONSE (MHz) 70
IRE
100
TPC 8. Distortion vs. Frequency; G = +2
TPC 11. Differential Gain and Phase
-20 G = +2 RF = 301 RL = 100 VO = 2V p-p VS = 5V THIRD
-30 -35 -40 -45
DISTORTION (dBc)
-30
DISTORTION (dBc)
G = +10 RF = 200 RL = 100 VO = 2V p-p
SECOND
-40 SECOND -50
-50 -55 -60 -65 -70 -75
-60
THIRD
-70
-80 1 10 FREQUENCY (MHz) 100 200
-80 5 10 70
FREQUENCY (MHz)
TPC 9. Distortion vs. Frequency; G = +2; VS = 5 V
TPC 12. Distortion vs. Frequency; G = +10
-6-
REV. F
AD8009
-35 -40 -45 -50
DISTORTION (dBc)
10 0
G = +2 RF = 301 RL = 100 100mV p-p ON TOP OF VS
250MHz
-10
70MHz
-20
-55 -60 -65 -70 -75 -80 -85 -90 -95 -10 -8 -6 -4 -2 0 2 4
50 50 200 22.1 50 POUT
PSRR (dB)
-30 -40 -50 -60 -70 0.03 0.1
-PSRR
5MHz
+PSRR
6
8
10
12
14
1
10
100
500
POUT (dBm)
FREQUENCY (MHz)
TPC 13. Third Harmonic Distortion vs. POUT; (G = +10)
TPC 16. PSRR vs. Frequency
50 45
22.1 200
300
250
50 50 50
INPUT CURRENT (pA/ Hz)
INTERCEPT POINT (dBm)
40 35 30 25 20 15 10 10
POUT
200
150
100 NONINVERTING CURRENT 50 INVERTING CURRENT 0
100 FREQUENCY (MHz)
250
10
100
1k
10k
100k
1M
10M
100M 250M
FREQUENCY (Hz)
TPC 14. Two Tone, Third Order IMD Intercept vs. Frequency; G = +10
TPC 17. Current Noise vs. Frequency
1M
0
-10 -15
301 301 VIN = 200mV p-p 154 154 VO 100
TRANSRESISTANCE ( )
100k
GAIN
-40
-20
PHASE (Degrees)
-25
CMRR (dB)
-30 -35 -40 -45 -50 -55
10k
RL = 100
PHASE
-80
1k
-120
100 0.01
0.1
1
10
100
-160 1000
-60 1 10 100 FREQUENCY (MHz) 1000
FREQUENCY (MHz)
TPC 15. Transresistance and Phase vs. Frequency
TPC 18. CMRR vs. Frequency
REV. F
-7-
AD8009
2.0
100
OUTPUT RESISTANCE ( )
G = +2 RF = 301
1.8
10
1.6
1
(VSWR)
1.4
0.1
1.2
1.0
0.01 0.03 0.1 1 10 100 500
0 0.1
1
FREQUENCY (MHz)
10 FREQUENCY (MHz)
100
500
TPC 19. Output Resistance vs. Frequency
TPC 22. Input VSWR; G = +10
10
20 18
INPUT VOLTAGE NOISE (nV/ Hz)
8
POUT MAX (dBm)
16 14 12 10 8
RF
G = +2 RF = 301
6
G = +10 RF = 200
4
6 2 4 2 0 10 0 100 1k 10k 100k 1M 10M 100M 250M 5
RG
50 50
POUT
50
10 FREQUENCY (MHz)
100
250
FREQUENCY (Hz)
TPC 20. Voltage Noise vs. Frequency
TPC 23. Maximum Output Power vs. Frequency
25
-20 -30
20
-40 NOISE FIGURE (dB)
15
G = +10 RF = 200
-50 S12 (dB)
10 100 SOURCE RESISTANCE ( ) 500 G = +10 RF = 301 RL = 100
-60 -70 -80
10
5
-90
0
1
1
10 100 FREQUENCY (MHz)
1000
TPC 21. Noise Figure
TPC 24. Reverse Isolation (S12); G = +10
-8-
REV. F
AD8009
2.2
CCOMP 49.9 49.9 200
2.0 1.8 (VSWR) 1.6 1.4
G = +2 RF = 301 RL = 150 VO = 2V p-p
22.1
CCOMP = 0pF 1.2 CCOMP = 3pF 1.0 0 0.1
500mV
1ns
1
10 FREQUENCY (MHz)
100
500
TPC 25. Output VSWR; G = +10
TPC 28. 2 V Transient Response; G = +2
100 90
VOUT
G = +10 RF = 200 RL = 100
G = +2 RF = 301 RL = 150 VO = 4V p-p
VIN = 2VSTEP
10 0%
2V
2V
250ns
1V
1.5ns
TPC 26. Overdrive Recovery; G = +10
TPC 29. 4 V Transient Response; G = +2
G = +2 RF = 301 RL = 150 VO = 200mV p-p
G = +10 RF = 200 RL = 100 VO = 200mV p-p
50mV
1ns
50mV
2ns
TPC 27. 2 V Transient Response; G = +2
TPC 30. Small Signal Transient Response; G = +10
REV. F
-9-
AD8009
G = +10 RF = 200 RL = 100 VO = 2V p-p V O
500mV
2ns
50mV
VS = 5V G = +2 RF = 301 RL = 150 VO = 200mV p-p
1ns
TPC 31. 2 V Transient Response; G = +10
TPC 34. 2 V Transient Response; VS = 5 V; G = +2
8
12 CA = 2pF 3dB/div 9 6 CA = 1pF 1dB/div CA = 0pF 1dB/div
VOUT = 200mV p-p
G = +10 RF = 200 RL = 100 VO = 4V p-p
7 6 5
GAIN (dB)
3
GAIN (dB)
4 3 2 1 0
VIN 50 499 CA 499 100 VOUT
0 -3 -6 -9 -12 -15 1 10 100 FREQUENCY (MHz) 1000
1V
3ns
-1
TPC 32. 4 V Transient Response; G = +10
TPC 35. Small Signal Frequency Response vs. Parasitic Capacitance
CA = 2pF CA = 1pF
VIN 50 CA 499 499
VOUT 100
V O
VOUT = 200mV p-p VS = 5V CA = 0pF
50mV
VS = 5V G = +2 RF = 301 RL = 150 VO = 200mV p-p
1ns
40mV
1.5ns
TPC 33. Small Signal Transient Response; VS = 5 V; G = +2
TPC 36. Small Signal Pulse Response vs. Parasitic Capacitance
-10-
REV. F
AD8009
HP8753D
0 -10 AD8009 G=2 RF = RG= 301 DRIVING WAVETEK 5201 TUNABLE BPF fC = 50MHz
Z OUT = 50 +5V 0.001 F 3 49.9 2 4 301 7
Z IN = 50
REJECTION (dB)
-20 -30
0.1 F
+
10 F
-40 -50 -60 -70 -80 -90
AD8009
6
49.9
WAVETEK 5201 BPF
301 -5V
0.001 F
0.1 F
10 F +
CENTER 50.000 MHz
SPAN 80.000 MHz
TPC 37. AD8009 Driving a Band-Pass RF Filter
TPC 38. Frequency Response of Band-Pass Filter Circuit
APPLICATIONS
All current feedback op amps are affected by stray capacitance on their -INPUT. TPCs 35 and 36 illustrate the AD8009's response to such capacitance. TPC 35 shows the bandwidth can be extended by placing a capacitor in parallel with the gain resistor. The small signal pulse response corresponding to such an increase in capacitance/bandwidth is shown in TPC 36. As a practical consideration, the higher the capacitance on the -INPUT to GND, the higher RF needs to be to minimize peaking/ringing.
RF Filter Driver
TPC 37 shows a circuit for driving and measuring the frequency response of a filter, a Wavetek 5201 tunable band-pass filter that is tuned to a 50 MHz center frequency. The HP8753D network provides a stimulus signal for the measurement. The analyzer has a 50 source impedance that drives a cable that is terminated in 50 at the high impedance noninverting input of the AD8009. The AD8009 is set at a gain of +2. The series 50 resistor at the output, along with the 50 termination provided by the filter and its termination, yield an overall unity gain for the measured path. The frequency response plot of TPC 38 shows the circuit to have an insertion loss of 1.3 dB in the pass band and about 75 dB rejection in the stop band.
The output drive capability, wide bandwidth, and low distortion of the AD8009 are well suited for creating gain blocks that can drive RF filters. Many of these filters require that the input be driven by a 50 source, while the output must be terminated in 50 for the filters to exhibit their specified frequency response.
REV. F
-11-
AD8009
75 IOUTR 75 RED 75 COAX PRIMARY MONITOR
ADV7160/ ADV7162
IOUTG 75 GREEN 75
IOUTB 75 BLUE 75
5V + 0.1 F 3 7 10 F 75 COAX RED 75 ADDITIONAL MONITOR
AD8009
2 301 301
6 4
75
0.1 F -5V
+
10 F
3
AD8009
2 301 301 3
6
75 GREEN 75
AD8009
2
6
75 BLUE 75
301
301
Figure 4. Driving an Additional High Resolution Monitor Using Three AD8009s
RGB Monitor Driver
High resolution computer monitors require very high full power bandwidth signals to maximize their display resolution. The RGB signals that drive these monitors are generally provided by a current-out RAMDAC that can directly drive a 75 doubly terminated line. There are times when the same output wants to be delivered to additional monitors. The termination provided internally by each monitor prohibits the ability to simply connect a second monitor in parallel with the first. Additional buffering must be provided. Figure 4 shows a connection diagram for two high resolution monitors being driven by an ADV7160 or ADV7162, a 220 MHz (Megapixel per second) triple RAMDAC. This pixel rate requires a driver whose full power bandwidth is at least half the pixel rate or 110 MHz. This is to provide good resolution for a worst-case signal that swings between zero scale and full scale on adjacent pixels.
The primary monitor is connected in the conventional fashion with a 75 termination to ground at each end of the 75 cable. Sometimes this configuration is called "doubly terminated" and is used when the driver is a high output impedance current source. For the additional monitor, each of the RGB signals close to the RAMDAC output is applied to a high input impedance, noninverting input of an AD8009 that is configured for a gain of +2. The outputs each drive a series 75 resistor, cable, and termination resistor in the monitor that divides the output signal by two, thus providing an overall unity gain. This scheme is referred to as "back termination" and is used when the driver is a low output impedance voltage source. Back termination requires that the voltage of the signal be double the value that the monitor sees. Double termination requires that the output current be double the value that flows in the monitor termination.
-12-
REV. F
AD8009
Driving a Capacitive Load
A capacitive load, like that presented by some A/D converters, can sometimes be a challenge for an op amp to drive depending on the architecture of the op amp. Most of the problem is caused by the pole created by the output impedance of the op amp and the capacitor that is driven. This creates extra phase shift that can eventually cause the op amp to become unstable. One way to prevent instability and improve settling time when driving a capacitor is to insert a resistor in series between the op amp output and the capacitor. The feedback resistor is still connected directly to the output of the op amp, while the series resistor provides some isolation of the capacitive load from the op amp output.
+5V G = +2: RF = 301 = RG 0.001 F 7 0.1 F + 10 F G = +10: RF = 200 , RG = 22.1 3 RT 49.9
Figure 5 shows such a circuit with an AD8009 driving a 50 pF load. With RS = 0, the AD8009 circuit will be unstable. For a gain of +2 and +10, it was found experimentally that setting RS to 42.2 will minimize the 0.1% settling time with a 2 V step at the output. The 0.1% settling time was measured to be 40 ns with this circuit. For smaller capacitive loads, a smaller RS will yield optimal settling time, while a larger RS will be required for larger capacitive loads. Of course, a larger capacitance will always require more time for settling to a given accuracy than a smaller one, and this will be lengthened by the increase in RS required. At best, a given RC combination will require about seven time constants by itself to settle to 0.1%, so a limit will be reached where too large a capacitance cannot be driven by a given op amp and still meet the system's required settling time specification.
AD8009
2 4
6 2VSTEP
RS CL 50pF
RG
RF 0.001 F -5V 0.1 F + 10 F
Figure 5. Capacitive Load Drive Circuit
REV. F
-13-
AD8009
OUTLINE DIMENSIONS 8-Lead Standard Small Outline Package [SOIC] (R-8)
Dimensions shown in millimeters and (inches)
5.00 (0.1968) 4.80 (0.1890)
8 5 4
4.00 (0.1574) 3.80 (0.1497)
1
6.20 (0.2440) 5.80 (0.2284)
1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY SEATING 0.10 PLANE
1.75 (0.0688) 1.35 (0.0532) 8 0.25 (0.0098) 0 0.17 (0.0067)
0.50 (0.0196) 0.25 (0.0099)
45
0.51 (0.0201) 0.31 (0.0122)
1.27 (0.0500) 0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
5-Lead Small Outline Transistor Package [SOT-23] (RT-5)
Dimensions shown in millimeters
2.90 BSC
5
4
1.60 BSC
1 2 3
2.80 BSC
PIN 1 0.95 BSC 1.30 1.15 0.90 1.90 BSC
1.45 MAX
0.22 0.08 10 5 0 0.60 0.45 0.30
0.15 MAX
0.50 0.30
SEATING PLANE
COMPLIANT TO JEDEC STANDARDS MO-178AA
-14-
REV. F
AD8009 Revision History
Location 9/04--Data Sheet changed from REV. E to REV. F. Page
Changes to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Change to TPC 37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3/03--Data Sheet changed from REV. D to REV. E.
Updated Data Sheet Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Universal Changes to FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Changes to Figure 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Deleted AD8009EB from ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Inserted new TPC 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Inserted new TPC 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Inserted new TPC 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Inserted new TPCs 33 and 34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
REV. F
-15-
-16-
C01011-0-9/04(F)

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