a
AD8009
REV. F
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reliable. However, no responsibility is assumed by Analog Devices for its
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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.
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 © 2004 Analog Devices, Inc. All rights reserved.
1 GHz, 5,500 V/s
Low Distortion Amplifier
FUNCTIONAL BLOCK DIAGRAMS
8-Lead Plastic SOIC (R-8) 5-Lead SOT-23 (RT-5)
PRODUCT DESCRIPTION
The AD8009 is an ultrahigh speed current feedback amplifier
with a phenomenal 5,500 V/µs 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 main-
tained 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 –40°C to +85°C.
The AD8009 is also available in an SOT-23-5 and will operate
over the commercial temperature range of 0°C to 70°C.
–30
–80
–40
–50
–60
–70
–100
–90
1
DISTORTION (dBc)
FREQUENCY RESPONSE (MHz)
7010
G = 2
RF = 301
VO = 2V p-p
SECOND
150LOAD
SECOND
100LOAD
THIRD
150LOAD
THIRD
100LOAD
Figure 2. Distortion vs. Frequency; G = +2
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
FREQUENCY RESPONSE (MHz)
1
2
1
–8
0
–1
–2
–3
–4
–5
–6
–7
100010
NORMALIZED GAIN (dB)
100
G = +2
RF = 301
RL = 150
G = +10
RF = 200
RL = 100
VO = 2V p-p
Figure 1. Large Signal Frequency Response; G = +2 and +10
1
VOUT
AD8009
–VS
+IN
2
34
5+VS
–IN
1
2
3
4
8
7
6
5
NC = NO CONNECT
AD8009
NC
–IN
+IN
–V
S
NC
OUT
+V
S
NC
–2– REV. F
AD8009–SPECIFICATIONS
(@ TA = 25C, VS = 5 V, RL = 100 ; for R Package: RF = 301 for G = +1, +2,
RF = 200 for G = +10; for RT Package: RF = 332 for G = +1, RF = 226 for G = +2 and RF = 191 for G = +10, unless otherwise noted.)
AD8009AR/JRT
Model Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Small Signal Bandwidth, V
O
= 0.2 V p-p
R Package G = +1, R
F
= 301 Ω1,000 MHz
RT Package G = +1, R
F
= 332 Ω845 MHz
G = +2 480 700 MHz
G = +10 300 350 MHz
Large Signal Bandwidth, V
O
= 2 V p-p G = +2 390 440 MHz
G = +10 235 320 MHz
Gain Flatness 0.1 dB, V
O
= 0.2 V p-p G = +2, R
L
= 150 Ω45 75 MHz
Slew Rate G = +2, R
L
= 150 Ω, 4 V Step 4,500 5,500 V/µs
Settling Time to 0.1% G = +2, R
L
= 150 Ω, 2 V Step 10 ns
G = +10, 2 V Step 25 ns
Rise and Fall Time G = +2, R
L
= 150 Ω, 4 V Step 0.725 ns
HARMONIC/NOISE PERFORMANCE
Second Harmonic G = +2, V
O
= 2 V p-p 10 MHz –73 dBc
20 MHz –66 dBc
70 MHz –56 dBc
Third Harmonic 10 MHz –77 dBc
20 MHz –75 dBc
70 MHz –58 dBc
Third Order Intercept (3IP) 70 MHz 26 dBm
W.R.T. Output, G = +10 150 MHz 18 dBm
250 MHz 12 dBm
Input Voltage Noise f = 10 MHz 1.9 nV/√Hz
Input Current Noise f = 10 MHz, +In 46 pA/√Hz
f = 10 MHz, –In 41 pA/√Hz
Differential Gain Error NTSC, G = +2, R
L
= 150 Ω0.01 0.03 %
NTSC, G = +2, R
L
= 37.5 Ω0.02 0.05 %
Differential Phase Error NTSC, G = +2, R
L
= 150 Ω0.01 0.03 Degrees
NTSC, G = +2, R
L
= 37.5 Ω0.04 0.08 Degrees
DC PERFORMANCE
Input Offset Voltage 25 mV
T
MIN
to T
MAX
7mV
Offset Voltage Drift 4µV/°C
–Input Bias Current 50 150 ±µA
T
MIN
to T
MAX
75 ±µA
+Input Bias Voltage 50 150 ±µA
T
MIN
to T
MAX
75 ±µA
Open-Loop Transresistance 90 250 kΩ
T
MIN
to T
MAX
170 kΩ
INPUT CHARACTERISTICS
Input Resistance +Input 110 kΩ
–Input 8 Ω
Input Capacitance +Input 2.6 pF
Input Common-Mode Voltage Range 3.8 ±V
Common-Mode Rejection Ratio V
CM
= ±2.5 50 52 dB
OUTPUT CHARACTERISTICS
Output Voltage Swing ±3.7 ±3.8 V
Output Current R
L
= 10 Ω, P
D
Package = 0.7 W 150 175 mA
Short-Circuit Current 330 mA
POWER SUPPLY
Operating Range +5 ±6V
Quiescent Current 14 16 mA
T
MIN
to T
MAX
18 mA
Power Supply Rejection Ratio V
S
= ±4 V to ±6 V 64 70 dB
Specifications subject to change without notice.
–3–
REV. F
AD8009
SPECIFICATIONS
(@ TA = 25C, VS = 5 V, RL = 100 , for R Package: RF = 301 for G = +1, +2,
RF = 200 for G = +10).
AD8009AR/JRT
Model Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Small Signal Bandwidth, V
O
= 0.2 V p-p
G = +1, R
F
= 301 Ω630 MHz
G = +2 430 MHz
G = +10 300 MHz
Large Signal Bandwidth, V
O
= 2 V p-p G = +2 365 MHz
G = +10 250 MHz
Gain Flatness 0.1 dB, V
O
= 0.2 V p-p G = +2, R
L
= 150 Ω65 MHz
Slew Rate G = +2, R
L
= 150 Ω, 4 V Step 2,100 V/µs
Settling Time to 0.1% G = +2, R
L
= 150 Ω, 2 V Step 10 ns
G = +10, 2 V Step 25 ns
Rise and Fall Time G = +2, R
L
= 150 Ω, 4 V Step 0.725 ns
HARMONIC/NOISE PERFORMANCE
Second Harmonic G = +2, V
O
= 2 V p-p 10 MHz –74 dBc
20 MHz –67 dBc
70 MHz –48 dBc
Third Harmonic 10 MHz –76 dBc
20 MHz –72 dBc
70 MHz –44 dBc
Input Voltage Noise f = 10 MHz 1.9 nV/√Hz
Input Current Noise f = 10 MHz, +In 46 pA/√Hz
f = 10 MHz, –In 41 pA/√Hz
DC PERFORMANCE
Input Offset Voltage 14 mV
–Input Bias Current 50 150 ±µA
+Input Bias Voltage 50 150 ±µA
INPUT CHARACTERISTICS
Input Resistance +Input 110 kΩ
–Input 8 Ω
Input Capacitance +Input 2.6 pF
Input Common-Mode Voltage Range 1.2 to 3.8 V
Common-Mode Rejection Ratio V
CM
= 1.5 V to 3.5 V 50 52 dB
OUTPUT CHARACTERISTICS
Output Voltage Swing 1.1 to 3.9 V
Output Current R
L
= 10 Ω, P
D
Package = 0.7 W 175 mA
Short-Circuit Current 330 mA
POWER SUPPLY
Operating Range +5 ±6V
Quiescent Current 10 12 mA
Power Supply Rejection Ratio V
S
= 4.5 V to 5.5 V 64 70 dB
Specifications subject to change without notice.
AD8009
–4– REV. F
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.
ABSOLUTE MAXIMUM RATINGS
1
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.6 V
Internal Power Dissipation
2
Small Outline Package (R) . . . . . . . . . . . . . . . . . . . . . . . 0.75 W
Input Voltage (Common-Mode) . . . . . . . . . . . . . . . . . . . . ±V
S
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . ±3.5 V
Output Short-Circuit Duration
. . . . . . . . . . . . . . . . . . . . . .Observe Power Derating Curves
Storage Temperature Range R Package . . . . –65°C to +125°C
Operating Temperature Range (A Grade) . . . –40°C to +85°C
Operating Temperature Range (J Grade) . . . . . . . 0°C to 70°C
Lead Temperature Range (Soldering 10 sec) . . . . . . . . . 300°C
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent 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: θ
JA
= 155°C/W.
5-Lead SOT-23 Package: θ
JA
= 240°C/W.
MAXIMUM POWER DISSIPATION
The maximum power that can be safely dissipated by the AD8009
is limited by the associated rise in junction temperature. The maxi-
mum safe junction temperature for plastic encapsulated devices
is determined by the glass transition temperature of the plastic,
approximately 150°C. 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 tempera-
ture of 175°C 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 tempera-
ture (150°C) is not exceeded under all conditions. To ensure
proper operation, it is necessary to observe the maximum power
derating curves.
AMBIENT TEMPERATURE (ⴗC)
9
0
80
2.0
1.0
0
1.5
0.5
–50
T
J
= 150 C
MAXIMUM POWER DISSIPATION (W)
706050403020100–40 –30 –20 –10
8-LEAD SOIC PACKAGE
5-LEAD SOT-23 PACKAGE
Figure 3. Plot of Maximum Power Dissipation vs.
Temperature
ORDERING GUIDE
Temperature Package Package
Model Range Description Option Branding
AD8009AR –40°C to +85°C8-Lead SOIC R-8
AD8009AR-REEL –40°C to +85°C8-Lead SOIC R-8
AD8009AR-REEL7 –40°C to +85°C8-Lead SOIC R-8
AD8009ARZ*–40°C to +85°C8-Lead SOIC R-8
AD8009ARZ-REEL*–40°C to +85°C8-Lead SOIC R-8
AD8009ARZ-REEL7*–40°C to +85°C8-Lead SOIC R-8
AD8009JRT-R2 0°C to 70°C5-Lead SOT-23 RT-5 HKJ
AD8009JRT-REEL 0°C to 70°C5-Lead SOT-23 RT-5 HKJ
AD8009JRT-REEL7 0°C to 70°C5-Lead SOT-23 RT-5 HKJ
AD8009JRTZ-REEL* 0°C to 70°C5-Lead SOT-23 RT-5 HKJ
AD8009JRTZ-REEL7* 0°C to 70°C5-Lead SOT-23 RT-5 HKJ
AD8009ACHIPS Die
*Z = Pb-free part.
–5–
REV. F
AD8009
FREQUENCY (MHz)
NORMALIZED GAIN (dB)
10 100
3
2
1
0
–1
–6
–7
–2
–3
–4
–5
11000
R PACKAGE:
R
L
= 100⍀
V
O
= 200mV p–p
G = +1, +2: R
F
= 301⍀
G = +10: R
F
= 200⍀
RT PACKAGE:
G = +1: R
F
= 332⍀
G = +2: R
F
= 226⍀
G = +10: R
F
= 191⍀
G = +1, R
G = +10, R AND RT
G = +2, R AND RT
G = +1, RT
TPC 1. Frequency Response; G = +1, +2, +10,
Rand RT Packages
GAIN (dB)
7
6
5
4
3
2
1
0
–1
–2
8
1001 100010
FREQUENCY (MHz)
G = +2
R
F
= 301⍀
R
L
= 150⍀
V
O
AS SHOWN
4V p-p
2V p-p
TPC 2. Large Signal Frequency Response; G = +2
GAIN (dB)
7
6
5
4
3
2
1
0
–1
–2
8
1001 100010
FREQUENCY (MHz)
G = +2
R
F
= 301⍀
R
L
= 150⍀
V
O
= 2V p–p
–40ⴗC
+85ⴗC
–40ⴗC
+85ⴗC
TPC 3. Large Signal Frequency Response vs.
Temperature; G = +2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
6.2
GAIN FLATNESS (dB)
FREQUENCY (MHz)
10 1001 1000
G = +2
RF = 301⍀
RL = 150⍀
VO = 200mV p-p
TPC 4. Gain Flatness; G = +2
FREQUENCY (MHz)
–0.3
–0.2
–0.1
0
0.1
0.2
0.3
0.4
110100 1000 10000
GAIN FLATNESS (dB)
G = +2
R
F
= 301⍀
R
L
= 150⍀
V
O
= 200mV p-p
V
S
= 5V
TPC 5. Gain Flatness; G = +2; V
S
= 5 V
GAIN (dB)
21
20
19
18
17
16
15
14
13
12
22
1001 100010
FREQUENCY (MHz)
G = +10
R
F
= 200⍀
R
L
= 100⍀
V
O
AS SHOWN
2V p-p
4V p-p
TPC 6. Large Signal Frequency Response; G = +10
Typical Performance Characteristics–
AD8009
–6– REV. F
GAIN (dB)
21
20
19
18
17
16
15
14
13
12
22
1001 100010
FREQUENCY (MHz)
G = +10
RF = 200⍀
RL = 100⍀
VO = 2V p-p
–40ⴗC
+85ⴗC
TPC 7. Large Signal Frequency Response vs.
Temperature; G = +10
DISTORTION (dBc)
–30
–80
–40
–50
–60
–70
–100
–90
THIRD,
150⍀ LOAD
THIRD,
100⍀ LOAD
FREQUENCY RESPONSE (MHz)
11070
SECOND,
100⍀ LOAD
SECOND,
150⍀ LOAD
G = 2
RF = 301⍀
VO = 2V p-p
TPC 8. Distortion vs. Frequency; G = +2
FREQUENCY (MHz)
–20
–80
1200
DISTORTION (dBc)
10 100
–30
–40
–50
–60
–70
G = +2
RF = 301⍀
RL = 100⍀
VO = 2V p-p
VS = 5V
THIRD
SECOND
TPC 9. Distortion vs. Frequency; G = +2; V
S
= 5 V
–35
–70
–85
–40
–65
–75
–80
–45
–55
–50
–60
DISTORTION (dBc)
P
OUT
(dBm)
–10 12–6 –4 –2 0 2 4 6 8 10 14
–8
200⍀
P
OUT
22.1⍀
50⍀
50⍀
50⍀
250MHz
70MHz
5MHz
TPC 10. Second Harmonic Distortion vs. P
OUT
; (G = +10)
IRE 100
0
0.02
DIFF GAIN (%)
–0.02
0.00
–0.01
0.01
R
L
= 37.5⍀
R
L
= 150⍀
G = +2
R
F
= 301⍀
G = +2
R
F
= 301⍀
R
L
= 37.5⍀
R
L
= 150⍀
0.10
DIFF PHASE (Degrees)
–0.10
–0.00
–0.05
0.05
IRE 100
0
TPC 11. Differential Gain and Phase
–30
–35
–80
–40
–45
–50
–55
–60
–65
–70
–75
DISTORTION (dBc)
70105
FREQUENCY (MHz)
G = +10
R
F
= 200⍀
R
L
= 100⍀
V
O
= 2V p-p
SECOND
THIRD
TPC 12. Distortion vs. Frequency; G = +10
–7–
REV. F
AD8009
POUT (dBm)
DISTORTION (dBc)
–45
–80
–95
–10 –8 12–6 –4 –2 0 2 4 6 8 10
–50
–75
–85
–90
–55
–65
–60
–70
–40
–35
14
5MHz
70MHz
250MHz
200⍀
P
OUT
22.1⍀
50⍀
50⍀
50⍀
TPC 13. Third Harmonic Distortion vs. P
OUT
; (G = +10)
INTERCEPT POINT (dBm)
FREQUENCY (MHz)
10 250100
10
50
45
40
35
30
25
20
15
200⍀
P
OUT
22.1⍀
50⍀
50⍀
50⍀
TPC 14. Two Tone, Third Order IMD Intercept vs.
Frequency; G = +10
TRANSRESISTANCE (⍀)
1M
100k
10k
1k
0.01 0.1 1001
GAIN
PHASE
R
L
= 100⍀
100010
PHASE (Degrees)
0
–40
–80
–120
FREQUENCY (MHz)
–160
100
TPC 15. Transresistance and Phase vs. Frequency
FREQUENCY (MHz)
0.03 0.1 10010
10
0
–10
–20
–30
–40
–50
–60
–70
1 500
PSRR (dB)
+PSRR
G = +2
RF = 301⍀
RL = 100⍀
100mV p-p ON TOP OF VS
–PSRR
TPC 16. PSRR vs. Frequency
FREQUENCY (Hz)
300
0
10 100 250M1k 10k 100k 1M 10M 100M
250
200
150
100
50
NONINVERTING CURRENT
INVERTING CURRENT
INPUT CURRENT (pA/
Hz)
TPC 17. Current Noise vs. Frequency
V
IN
=
200mV p-p
100⍀
V
O
301⍀
154⍀
301⍀
154⍀
–15
–20
–25
–30
–35
–40
–45
–50
–55
–60
–10
CMRR (dB)
1001100010
FREQUENCY (MHz)
TPC 18. CMRR vs. Frequency
AD8009
–8– REV. F
100
10
1
0.1
0.01
0.03 0.1 100101 500
OUTPUT RESISTANCE (⍀)
FREQUENCY (MHz)
G = +2
R
F
= 301⍀
TPC 19. Output Resistance vs. Frequency
INPUT VOLTAGE NOISE (nV/ Hz)
0
10
8
6
4
2
FREQUENCY (Hz)
10 100 250M1k 10k 100k 1M 10M 100M
TPC 20. Voltage Noise vs. Frequency
SOURCE RESISTANCE (⍀)
NOISE FIGURE (dB)
25
20
15
10
5
0100101 500
G = +10
R
F
= 301⍀
R
L
= 100⍀
TPC 21. Noise Figure
FREQUENCY (MHz)
(VSWR)
0.1 1 10010
2.0
1.8
1.6
1.4
1.2
1.0
0500
TPC 22. Input VSWR; G = +10
250
20
18
0
16
14
12
10
8
6
4
2
POUT MAX (dBm)
FREQUENCY (MHz)
510010
RF
POUT
RG
50⍀
50⍀
50⍀
G = +2
RF = 301⍀
G = +10
RF = 200⍀
TPC 23. Maximum Output Power vs. Frequency
–70
–80
–90
–60
–50
–40
–30
–20
S12 (dB)
1001 100010
FREQUENCY (MHz)
G = +10
RF = 200⍀
TPC 24. Reverse Isolation (S
12
); G = +10
–9–
REV. F
AD8009
(VSWR)
2.0
1.8
1.6
1.4
1.2
1.0
0
2.2
FREQUENCY (MHz)
0.1 1 10010
CCOMP = 0pF
CCOMP = 3pF
200
49.9
CCOMP
49.9
22.1
500
TPC 25. Output VSWR; G = +10
10
0%
100
90
VOUT
VIN = 2VSTEP
250ns
2V
2V
G = +10
RF = 200
RL = 100
TPC 26. Overdrive Recovery; G = +10
1ns
50mV
G = +2
RF = 301
RL = 150
VO = 200mV p-p
TPC 27. 2 V Transient Response; G = +2
1ns
500mV
G = +2
RF = 301
RL = 150
VO = 2V p-p
TPC 28. 2 V Transient Response; G = +2
1.5ns1V
G = +2
RF = 301
RL = 150
VO = 4V p-p
TPC 29. 4 V Transient Response; G = +2
2ns
50mV
G = +10
RF = 200
RL = 100
VO = 200mV p-p
TPC 30. Small Signal Transient Response; G = +10
AD8009
–10– REV. F
V
O
50mV 1ns
V
S
= 5V
G = +2
R
F
= 301⍀
R
L
= 150⍀
V
O
= 200mV p-p
TPC 34. 2 V Transient Response; V
S
= 5 V; G = +2
FREQUENCY (MHz)
10 1000
100
GAIN
(dB)
8
7
6
5
4
–1
3
2
1
0
12
9
6
3
0
–15
–12
–9
–6
–3
GAIN (dB)
50⍀
V
IN
C
A
499⍀
V
OUT
= 200mV p–p
V
OUT
499⍀100⍀
1
CA = 2pF
3dB/div
CA = 1pF
1dB/div
CA = 0pF
1dB/div
TPC 35. Small Signal Frequency Response vs.
Parasitic Capacitance
1.5ns
40mV
V
OUT
= 200mV p–p
V
S
= ⴞ5V
C
A
= 2pF
C
A
= 1pF
C
A
= 0pF
499⍀100⍀
50⍀
V
OUT
V
IN
C
A
499⍀
TPC 36. Small Signal Pulse Response vs.
Parasitic Capacitance
2ns
500mV
G = +10
R
F
= 200⍀
R
L
= 100⍀
V
O
= 2V p-p
TPC 31. 2 V Transient Response; G = +10
3ns
1V
G = +10
R
F
= 200⍀
R
L
= 100⍀
V
O
= 4V p-p
TPC 32. 4 V Transient Response; G = +10
V
O
50mV 1ns
V
S
= 5V
G = +2
R
F
= 301⍀
R
L
= 150⍀
V
O
= 200mV p-p
TPC 33. Small Signal Transient Response;
V
S
= 5 V; G = +2
–11–
REV. F
AD8009
10F
AD8009
HP8753D
49.9
301
49.9
+5V
–5V
301
3
10F
+
Z
OUT
= 50Z
IN
= 50
+
0.001F0.1F
0.001F0.1F
2
7
4
6
WAVETEK 5201
BPF
TPC 37. AD8009 Driving a Band-Pass RF Filter
CENTER 50.000 MHz SPAN 80.000 MHz
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
REJECTION (dB)
AD8009
G = 2
R
F
= R
G
= 301
DRIVING
WAVETEK 5201
TUNABLE BPF
f
C
= 50MHz
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/band-
width is shown in TPC 36.
As a practical consideration, the higher the capacitance on the
–INPUT to GND, the higher R
F
needs to be to minimize
peaking/ringing.
RF Filter Driver
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 Ω source, while the output must be terminated in
50 Ω for the filters to exhibit their specified frequency response.
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 Ω source impedance that drives a cable that is terminated in
50 Ω at the high impedance noninverting input of the AD8009.
The AD8009 is set at a gain of +2. The series 50 Ω resistor at the
output, along with the 50 Ω 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.
AD8009
–12– REV. F
10F
+
0.1F
AD8009 75
301
5V
301
2
7
3
6
+10F0.1F
4
–5V
AD8009 75
301
301
2
3
6
AD8009 75
301301
2
3
6
75COAX PRIMARY MONITOR
ADDITIONAL MONITOR
75 COAX
75
75
75
75
75
75
75
75
75
RED
GREEN
BLUE
RED
GREEN
BLUE
I
OUT
R
I
OUT
G
I
OUT
B
ADV7160/
ADV7162
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 Ω 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 Ω termination to ground at each end of the 75 Ω
cable. Sometimes this configuration is called “doubly termi-
nated” 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, noninvert-
ing input of an AD8009 that is configured for a gain of +2. The
outputs each drive a series 75 Ω 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.
–13–
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.
10F
+
0.1F0.001F
10F
+
0.1F
0.001F
AD8009
49.9
+5V
–5V
3
24
R
T
R
S
C
L
50pF
2V
STEP
7
6
R
F
R
G
G = +2: R
F
= 301 = R
G
G = +10: R
F
= 200, R
G
= 22.1
Figure 5. Capacitive Load Drive Circuit
Figure 5 shows such a circuit with an AD8009 driving a 50 pF
load. With R
S
= 0, the AD8009 circuit will be unstable. For a
gain of +2 and +10, it was found experimentally that setting R
S
to 42.2 Ω 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 R
S
will yield optimal
settling time, while a larger R
S
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 R
S
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
–14– REV. F
OUTLINE DIMENSIONS
8-Lead Standard Small Outline Package [SOIC]
(R-8)
Dimensions shown in millimeters and (inches)
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
0.50 (0.0196)
0.25 (0.0099) 45
8
0
1.75 (0.0688)
1.35 (0.0532)
SEATING
PLANE
0.25 (0.0098)
0.10 (0.0040)
85
41
5.00 (0.1968)
4.80 (0.1890)
4.00 (0.1574)
3.80 (0.1497)
1.27 (0.0500)
BSC
6.20 (0.2440)
5.80 (0.2284)
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
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
COMPLIANT TO JEDEC STANDARDS MS-012AA
5-Lead Small Outline Transistor Package [SOT-23]
(RT-5)
Dimensions shown in millimeters
PIN 1
1.60 BSC 2.80 BSC
1.90
BSC
0.95 BSC
1 3
4 5
2
0.22
0.08
10
5
0
0.50
0.30
0.15 MAX SEATING
PLANE
1.45 MAX
1.30
1.15
0.90
2.90 BSC
0.60
0.45
0.30
COMPLIANT TO JEDEC STANDARDS MO-178AA
–15–
REV. F
AD8009
Revision History
Location Page
9/04—Data Sheet changed from REV. E to REV. F.
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
–16–
C01011–0–9/04(F)