FEATURES
Low Cost Single (AD8051), Dual (AD8052) and Quad
(AD8054)
Voltage Feedback Architecture
Fully Specified at +3 V, +5 V and ⴞ5 V Supplies
Single Supply Operation
Output Swings to Within 25 mV of Either Rail
= 1K
= 1K
L
= +5 V
S
= 150 ⍀
L
= 100 ⍀
Input Voltage Range: –0.2 V to +4 V; V
High Speed and Fast Settling on +5 V:
110 MHz –3 dB Bandwidth (G = +1) (AD8051/AD8052)
150 MHz –3 dB Bandwidth (G = +1) (AD8054)
145 V/s Slew Rate
50 ns Settling Time to 0.1%
Small Packaging
AD8051 Available in SOT-23-5
AD8052 Available in SOIC-8
AD8054 Available in TSSOP-14
Good Video Specifications (G = +2)
Gain Flatness of 0.1 dB to 20 MHz; R
0.03% Differential Gain Error; R
0.03ⴗ Differential Phase Error; R
L
L
Low Distortion
–80 dBc Total Harmonic @ 1 MHz, R
Outstanding Load Drive Capability
Drives 45 mA, 0.5 V from Supply Rails (AD8051/AD8052)
Drives 50 pF Capacitive Load (G = +1) (AD8051/AD8052)
Low Power of 2.75 mA/Amplifier (AD8054)
Low Power of 4.4 mA/Amplifier (AD8051/AD8052)
APPLICATIONS
Coax Cable Driver
Active Filters
Video Switchers
A/D Driver
Professional Cameras
CCD Imaging Systems
CD/DVD ROM
Rail-to-Rail Amplifiers
AD8051/AD8052/AD8054
CONNECTION DIAGRAMS
(Top Views)
SO-8
AD8051
1
NC
2
–IN
3
+IN
4
S
NC = NO CONNECT
8
NC
7
+V
S
6
V
OUT
5
NC–V
R-8, SOIC (RM)R-14, TSSOP-14 (RU-14)
OUT1
–IN1
+IN1
–V
1
–
2
+
3
4
S
8
+V
S
7
OUT
6
–IN2
–
+
+IN2
5
AD8052
portable equipment. Low distortion and fast settling make them
ideal for active filter applications.
The AD8051/AD8052/AD8054 offer low power supply current and can operate on a single +3 V power supply. These
features are ideally suited for portable and battery powered
applications where size and power are critical.
The wide bandwidth and fast slew rate on a single +5 V supply
make these amplifiers useful in many general purpose, high speed
applications where dual power supplies of up to ±6 V and single
supplies from +3 V to +12 V are needed.
All of this low cost performance is offered in an 8-lead SOIC,
along with a tiny SOT-23-5 package (AD8051), a µSOIC
package (AD8052) and a TSSOP-14 (AD8054).
SOT-23-5 (RT)
AD8051
V
1
OUT
–V
2
S
3
1
OUT A
2
2IN A
3
+IN A
4
V+
AD8054
5
+IN B
6
2IN B2IN C
7
OUT B
+–
5
+V
S
4
–IN+IN
14
OUT D
13
2IN D
12
+IN D
11
V2
10
+IN C
9
8
OUT C
PRODUCT DESCRIPTION
The AD8051 (single), AD8052 (dual) and AD8054 (quad) are
low cost, voltage feedback, high speed amplifiers designed to
operate on +3 V, +5 V or ±5 V supplies. They have true single
supply capability with an input voltage range extending 200␣ mV
below the negative rail and within 1␣ V of the positive rail.
Despite their low cost, the AD8051/AD8052/AD8054 provide
excellent overall performance and versatility. The output voltage swing extends to within 25 mV of each rail, providing the
maximum output dynamic range with excellent overdrive recovery. This makes the AD8051/AD8052/AD8054 useful for video
electronics such as cameras, video switchers or any high speed
REV. B
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
Input Resistance290300kΩ
Input Capacitance1.41.5pF
Input Common-Mode Voltage Range–0.2 to 4–0.2 to 4V
Common-Mode Rejection RatioVCM = 0 V to +3.5 V72887086dB
OUTPUT CHARACTERISTICS
Output Voltage SwingR
Output CurrentV
= 10␣ kΩ to +2.5 V0.015 to 4.9850.03 to 4.975V
L
= 2␣ kΩ to +2.5 V0.1 to 4.90.025 to 4.9750.125 to 4.875 0.05 to 4.95V
R
L
= 150 Ω to +2.5 V0.3 to 4.625 0.2 to 4.80.55 to 4.40.25 to 4.65V
R
L
= 0.5 V to +4.5 V4530mA
OUT
T
MIN–TMAX
4530mA
Short Circuit CurrentSourcing8045mA
Sinking13085mA
Capacitive Load DriveG = +1 (AD8051/AD8052)50pF
G = +2 (AD8054)40pF
POWER SUPPLY
Operating Range312312V
Quiescent Current/Amplifier4.452.753.275 mA
Power Supply Rejection Ratio∆VS = ±1 V70806880dB
OPERATING TEMPERATURE RANGE–40+85 –40+85°C
NOTES
1
Refer to Figure 15.
Specifications subject to change without notice.
–2–
REV. B
Page 3
AD8051/AD8052/AD8054
SPECIFICATIONS
ParameterConditionsMinTypMax MinTypMax Units
DYNAMIC PERFORMANCE
–3 dB Small Signal BandwidthG = +1, V
Bandwidth for 0.1 dB FlatnessG = +2, V
Slew RateG = –1, V
Full Power ResponseG = +1, V
Settling Time to 0.1%G = –1, VO = 2 V Step5555ns
(@ TA = +25ⴗC, VS = +3 V, RL = 2 k⍀ to +1.5 V, unless otherwise noted)
AD8051A/AD8052AAD8054A
= 0.2 V p-p7011080135MHz
O
G = –1, +2, V
R
= 150 Ω to 2.5 V,
L
= 402 Ω for AD8051A/AD8052A17MHz
R
F
R
= 200 Ω for AD8054A10MHz
F
= 0.2 V p-p5065MHz
O
= 0.2 V p-p,
O
= 2 V Step90135110150V/µs
O
= 1 V p-p6585MHz
O
NOISE/DISTORTION PERFORMANCE
Total Harmonic Distortion
1
fC = 5 MHz, VO = 2 V p-p,
G = –1, R
= 100 Ω to +1.5 V–47–48dB
L
Input Voltage Noisef = 10 kHz1616nV/√Hz
Input Current Noisef = 10 kHz600600fA/√Hz
Differential Gain Error (NTSC)G = +2, V
Input Resistance290300kΩ
Input Capacitance1.41.5pF
Input Common-Mode Voltage Range–0.2 to 2–0.2 to 2V
Common-Mode Rejection RatioVCM = 0 V to 1.5 V72887086dB
OUTPUT CHARACTERISTICS
Output Voltage SwingR
Output CurrentV
= 10␣ kΩ to +1.5 V0.01 to 2.990.025 to 2.98V
L
= 2␣ kΩ to +1.5 V0.075 to 2.9 0.02 to 2.980.1 to 2.90.35 to 2.965V
R
L
R
= 150 Ω to +1.5 V0.2 to 2.75 0.125 to 2.8750.35 to 2.550.15 to 2.75V
L
= 0.5 V to +2.5 V4525mA
OUT
T
MIN–TMAX
4525mA
Short Circuit CurrentSourcing6030mA
Sinking9050mA
Capacitive Load DriveG = +1 (AD8051/AD8052)45pF
G = +2 (AD8054)35pF
POWER SUPPLY
Operating Range312312V
Quiescent Current/Amplifier4.24.82.6253.125 mA
Power Supply Rejection Ratio∆V
= +0.5 V68806880dB
S
OPERATING TEMPERATURE RANGE–40+85 – 40+85°C
NOTES
1
Refer to Figure 15.
Specifications subject to change without notice.
–3–REV. B
Page 4
(@ TA = +25ⴗC, VS = ⴞ5 V, RL = 2 k⍀ to Ground,
AD8051/AD8052/AD8054–SPECIFICATIONS
AD8051A/AD8052AAD8054A
ParameterConditionsMinTypMax MinTypMax Units
DYNAMIC PERFORMANCE
–3 dB Small Signal BandwidthG = +1, VO = 0.2 V p-p7011085160MHz
G = –1, +2, VO = 0.2 V p-p5065MHz
Bandwidth for 0.1 dB FlatnessG = +2, VO = 0.2 V p-p,
R
= 150 Ω,
L
R
= 1.1 kΩ for AD8051A/AD8052A20MHz
F
R
= 200 Ω for AD8054A15MHz
Slew RateG = –1, V
Full Power ResponseG = +1, VO = 2 V p-p4050MHz
Settling Time to 0.1%G = –1, VO = 2 V Step5040ns
NOISE/DISTORTION PERFORMANCE
Total Harmonic DistortionfC = 5 MHz, VO = 2 V p-p, G = +2–71–72dB
Input Voltage Noisef = 10 kHz1616nV/√Hz
Input Current Noisef = 10 kHz900900fA/√Hz
Differential Gain Error (NTSC)G = +2, R
Storage Temperature Range (R) . . . . . . . . . –65°C to +125°C
Operating Temperature Range (A Grade) . . . –40°C to +85°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.
The maximum power that can be safely dissipated by the AD8051/
AD8052/AD8054 is limited by the associated rise in junction
temperature. The maximum safe junction temperature for
ORDERING GUIDE
TemperaturePackagePackageBrand
ModelRangeDescriptionsOptions*Code
plastic encapsulated devices is determined by the glass transi-
tion temperature of the plastic, approximately +150°C. Tempo-
rarily exceeding this limit 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 +175°C for an
extended period can result in device failure.
While the AD8051/AD8052/AD8054 are internally short circuit
protected, this may not be sufficient to guarantee that the maxi-
mum junction temperature (+150°C) is not exceeded under
all conditions. To ensure proper operation, it is necessary to observe the maximum power derating curves.
Figure 2. Plot of Maximum Power Dissipation vs.
Temperature for AD8051/AD8052/AD8054
AD8051AR–40°C to +85°C8-Lead SOICSO-8
AD8051AR-REEL–40°C to +85°C13" Tape and ReelSO-8
AD8051AR-REEL7–40°C to +85°C7" Tape and ReelSO-8
AD8051ART-REEL–40°C to +85°C13" Tape and ReelRT-5H2A
AD8051ART-REEL7–40°C to +85°C7" Tape and ReelRT-5H2A
AD8052AR–40°C to +85°C8-Lead SOICSO-8
AD8052AR-REEL–40°C to +85°C13" Tape and ReelSO-8
AD8052AR-REEL7–40°C to +85°C7" Tape and ReelSO-8
AD8052ARM–40°C to +85°C8-Lead µSOICRM-8H4A
AD8052ARM-REEL–40°C to +85°C13" Tape and ReelRM-8H4A
AD8052ARM-REEL7–40°C to +85°C7" Tape and ReelRM-8H4A
AD8054AR–40°C to +85°C14-Lead SOICR-14
AD8054AR-REEL–40°C to +85°C13" Tape and ReelR-14
AD8054AR-REEL7–40°C to +85°C7" Tape and ReelR-14
AD8054ARU–40°C to +85°C14-Lead µSOICRU-14
AD8054ARU-REEL–40°C to +85°C13" Tape and ReelRU-14
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
AD8054ARU-REEL7–40°C to +85°C7" Tape and ReelRU-14
*R = Small Outline; RM = Micro Small Outline; RT = Surface Mount; RU = TSSOP .
accumulate on the human body and test equipment and can discharge without detection.
Although the AD8051/AD8052/AD8054 feature 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.
REV. B
WARNING!
ESD SENSITIVE DEVICE
–5–
Page 6
AD8051/AD8052/AD8054
3
2
1
0
–1
–2
–3
VS = +5V
–4
GAIN AS SHOWN
NORMALIZED GAIN – dB
R
–5
R
VO = 0.2V p-p
–6
–7
0.1110100
AS SHOWN
F
= 2kV
L
G = +10
R
= 2kV
F
G = +2
R
= 2kV
F
G = +5
R
= 2kV
F
FREQUENCY – MHz
G = +1
= 0
R
F
Figure 3. AD8051/AD8052 Normalized Gain vs.
Frequency; V
3
2
1
0
–1
–2
GAIN – dB
–3
–4
–5
–6
–7
0.1500110100
= +5 V
S
VS AS SHOWN
G = +1
= 2kV
R
L
= 0.2V p-p
V
O
VS = +3V
VS = 65V
FREQUENCY – MHz
VS = +5V
Figure 4. AD8051/AD8052 Gain vs. Frequency
vs. Supply
500
5
VS = +5V
4
GAIN AS SHOWN
3
AS SHOWN
R
F
= 5kV
R
L
2
= 0.2V p-p
V
O
1
0
–1
–2
–3
NORMALIZED GAIN – dB
–4
–5
–6
–7
100k
1M
G = +10
= 2kV
R
F
G = +5
= 2kV
R
F
FREQUENCY – Hz
G = +2
= 2kV
R
F
10M100M
G = +1
= 0
R
F
500M
Figure 6. AD8054 Normalized Gain vs. Frequency;
V
= +5 V
S
6
5
G = +1
R
4
C
3
V
2
1
GAIN – dB
0
–1
–2
–3
–4
100k
= 2kV
L
= 5pF
L
= 0.2V p-p
O
1M10M100M
FREQUENCY – Hz
+3V
+5V
65V
65V
+3V
+5V
500M
Figure 7. AD8054 Gain vs. Frequency vs. Supply
3
2
1
0
–1
–2
GAIN – dB
–3
VS = +5V
–4
G = +1
R
= 2kV
L
–5
= 0.2V p-p
V
O
TEMPERATURE AS SHOWN
–6
–7
0.1
FREQUENCY – MHz
–408C
+858C
+258C
500110100
Figure 5. AD8051/AD8052 Gain vs. Frequency vs.
Temperature
4
3
2
1
0
VS = +5V
–1
GAIN – dB
R
= 2kV TO 2.5V
L
–2
C
= 5pF
L
G = +1
–3
V
= 0.2V p-p
O
–4
–5
110100
FREQUENCY – MHz
+858C
+258C
–408C
Figure 8. AD8054 Gain vs. Frequency vs. Temperature
–6–
500
REV. B
Page 7
AD8051/AD8052/AD8054
80
40
–10
70
60
50
30
20
10
0
–20
30k 100k1M10M100M
GAIN
PHASE
458 PHASE
MARGIN
VS = +5V
R
L
= 2kV
CL = 5pF
FREQUENCY – Hz
180
135
90
45
0
500M
OPEN-LOOP GAIN – dB
PHASE MARGIN – Degrees
6.3
6.2
6.1
6.0
5.9
5.8
0.1
VS = +5V
G = +2
= 150V
R
L
= 806V
R
F
= 0.2V p-p
V
O
110100
FREQUENCY – MHz
5.7
5.6
GAIN FLATNESS – dB
5.5
5.4
5.3
Figure 9. AD8051/AD8052 0.1 dB Gain Flatness vs.
Frequency; G = +2
9
VS = 65V
= 4V p-p
V
O
VS = +5V
V
= 2V p-p
O
8
7
6
5
4
GAIN – dB
3
VS AS SHOWN
2
G = +2
= 2kV
R
L
1
= 2kV
R
F
AS SHOWN
V
O
0
–1
0.1500110100
FREQUENCY – MHz
6.3
6.2
6.1
6.0
5.9
5.8
VS = +5V
V
= 200
R
5.7
5.6
GAIN FLATNESS – dB
5.5
5.4
5.3
F
V
R
= 150
L
G = +2
= 0.2V p-p
V
O
110010
FREQUENCY – MHz
Figure 12. AD8054 0.1 dB Gain Flatness vs. Frequency;
G = +2
9
= 4V p-p
VS = +5V
= 2V p-p
V
O
8
7
6
5
4
GAIN – dB
3
VS AS SHOWN
2
G = +2
= 2kV
R
L
1
= 2kV
R
F
AS SHOWN
V
0
O
–1
0.1500110100
VS = 65V
V
O
FREQUENCY – MHz
Figure 10. AD8051/AD8052 Large Signal Frequency
Response; G = +2
80
70
60
50
40
30
20
10
OPEN-LOOP GAIN – dB
REV. B
0
–10
–20
0.015000.1110100
Figure 11. AD8051/AD8052 Open-Loop Gain and
Phase vs. Frequency
GAIN
PHASE
FREQUENCY – MHz
508 PHASE
MARGIN
VS = +5V
R
= 2kV
L
0
–45
–90
–135
PHASE – Degrees
–180
Figure 13. AD8054 Large Signal Frequency Response;
G = +2
Figure 14. AD8054 Open-Loop Gain and Phase
Margin vs. Frequency
–7–
Page 8
AD8051/AD8052/AD8054
20
2
VO = 2V p-p
30
2
40
2
VS = +5V, G = +1
50
2
60
2
70
2
80
2
90
2
TOTAL HARMONIC DISTORTION – dBc
100
2
110
2
= 100
R
L
12345
VS = +5V, G = +2
= 2kV, RL = 100
R
F
V
VS = +5V, G = +2
= 2kV, RL = 2k
R
F
FUNDAMENTAL FREQUENCY – MHz
VS = +3V, G = 21
= 2kV, RL = 100
R
F
V
VS = +5V, G = +1
= 2k
R
V
L
V
678910
V
Figure 15. Total Harmonic Distortion
230
240
250
260
270
280
290
2100
2110
WORST HARMONIC – dBc
2120
2130
2140
05.00.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
10MHz
5MHz
1MHz
OUTPUT VOLTAGE – V p-p
VS = +5V
= 2kV
R
L
G = +2
4.5
Figure 16. Worst Harmonic vs. Output Voltage
1000
VS = +5V
Hz
100
10
VOLTAGE NOISE – nA
1
1010M100
1k10k100k1M
FREQUENCY – Hz
Figure 18. Input Voltage Noise vs. Frequency
100
VS = +5V
10
1
CURRENT NOISE – pA Hz
0.1
1010M1001k10k100k1M
FREQUENCY – Hz
Figure 19. Input Current Noise vs. Frequency
0.10
NTSC SUBSCRIBER (3.58MHz)
0.08
0.06
0.04
0.02
0.00
20.02
DIFFERENTIAL
DIFFERENTIAL
VS = +5, G = +2
GAIN ERROR – %
20.04
R
= 2kV, RL AS SHOWN
F
20.06
0
0.10
20.05
20.10
20.15
20.20
20.25
PHASE ERROR – Degrees
1060207030804090
0.05
0.00
VS = +5, G = +2
R
= 2kV, RL AS SHOWN
F
0
50
MODULATING RAMP LEVEL – IRE
RL = 150V
RL = 1kV
100
RL = 1kV
RL = 150V
100501060207030804090
Figure 17. AD8051/AD8052 Differential Gain and Phase
Errors
0.10
NTSC SUBSCRIBER (3.58MHz)
0.05
0.00
GAIN – %
–0.05
VS = +5, G = +2
DIFFERENTIAL
DIFFERENTIAL
PHASE – Degrees
= 2kV, RL AS SHOWN
R
F
–0.10
1st6th2nd7th3rd8th4th9th5th10th 11th
0.3
0.2
0.1
0.0
VS = +5, G = +2
–0.1
= 2kV,
R
F
–0.2
AS SHOWN
R
L
–0.3
1st6th2nd7th3rd8th4th9th5th10th 11th
MODULATING RAMP LEVEL – IRE
RL = 1kV
RL = 150V
RL = 1kV
RL = 150V
Figure 20. AD8054 Differential Gain and Phase Errors
–8–
REV. B
Page 9
AD8051/AD8052/AD8054
INPUT STEPS – Volts p-p
60
0
40
30
20
10
50
70
0.5211.5
SETTING TIME TO 0.1% 2 ns
AD8051/AD8052
AD8054
VS = 15V
G = 21
R
L
= 2k
V
–10
VS = +5V
–20
= 2kV
R
F
= 2kV
R
L
–30
= 2V p-p
V
O
–40
–50
–60
–70
CROSSTALK – dB
–80
–90
–100
0.1
FREQUENCY – MHz
500110100
Figure 21. AD8052 Crosstalk (Output-to-Output) vs.
Frequency
0
VS = +5V
–10
–20
–30
–40
–50
–60
CMRR – dB
–70
–80
–90
–100
0.03500
0.1110100
FREQUENCY – MHz
Figure 22. CMRR vs. Frequency
–10
–20
–30
–40
–50
–60
–70
CROSSTALK – dB
–80
–90
–100
–110
0.1
RL = 100V
RL = 1kV
110
FREQUENCY – MHz
VS = 65V
R
= 1kV
F
= AS SHOWN
R
L
= 2V p-p
V
O
100
500
Figure 24. AD8054 Crosstalk (Output-to-Output) vs.
Frequency
20
VS = +5V
10
0
–10
–20
–30
–40
PSRR – dB
–50
–60
–70
–80
–PSRR
+PSRR
1500101000.10.01
FREQUENCY – MHz
Figure 25. PSRR vs. Frequency
100
31
10
3.1
1
0.31
0.1
OUTPUT RESISTANCE – V
0.031
0.01
Figure 23. Closed Loop Output Resistance vs. Frequency
REV. B
0.1110100500
VS = 15V
G = 11
FREQUENCY – MHz
Figure 26. Settling Time vs. Input Step
–9–
Page 10
AD8051/AD8052/AD8054
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
OUTPUT SATURATION VOLTAGE – Volts
0
06551015202530354045505560
VOH = +858C
VOH = +258C
VOH = –408C
LOAD CURRENT – mA
VOL = –408C
VS = +5V
VOL = +858C
VOL = +258C
70 75 80 85
Figure 27. AD8051/AD8052 Output Saturation Voltage vs.
Load Current
100
RL = 2kV
90
RL = 150V
80
1.00
VS = +5V
0.875
0.750
0.625
0.500
0.375
0.250
0.125
OUTPUT SATURATION VOLTAGE – Volts
0.00
0303 6 9 121518212427
+5V –VOH (–558C)
LOAD CURRENT – mA
+5V –VOH (+258C)
VOL (–558C)
+5V –VOH (+1258C)
VOL (+1258C)
VOL (+258C)
Figure 29. AD8054 Output Saturation Voltage vs. Load
Current
OPEN-LOOP GAIN – dB
70
VS = +5V
60
05
0.511.522.533.544.5
OUTPUT VOLTAGE – Volts
Figure 28. Open-Loop Gain vs. Output Voltage
–10–
REV. B
Page 11
AD8051/AD8052/AD8054
5
1.50V
Figure 30. 100 mV Step Response, G = +1
2.60
2.50
2.40
20ns
Figure 31. AD8051/AD8052 200 mV Step Response;
= +5 V, G = +1
V
S
2.5
VOLTS
Figure 33. Output Swing; G = –1, RL = +2 k
2.55
2.50
VOLTS
2.45
Ω
Figure 34. AD8054 100 mV Step Response; VS = +5 V,
G = +1
3.5
2.5
VOLTS
1.5
Figure 32. Large Signal Step Response; VS = +5 V, G = +2
4
3
2
1
21
22
23
24
Figure 35. Large Signal Step Response; VS = ±5 V, G = +1
REV. B
–11–
Page 12
AD8051/AD8052/AD8054
Overdrive Recovery
Overdrive of an amplifier occurs when the output and/or input
range are exceeded. The amplifier must recover from this overdrive condition. As shown in Figure 36, the AD8051/AD8052/
AD8054 recovers within 60␣ ns from negative overdrive and
within 45␣ ns from positive overdrive.
Figure 36.␣ Overdrive Recovery
Driving Capacitive Loads
Consider the AD8051/AD8052 in a closed-loop gain of +1 with
+V
= 5 V and a load of 2 kΩ in parallel with 50 pF. Figures 37
S
and 38 show its frequency and time domain responses, respectively, to a small-signal excitation. The capacitive load drive of
the AD8051/AD8052/AD8054 can be increased by adding a
low valued resistor in series with the load. Figures 39 and 40
show the effect of a series resistor on capacitive drive for varying
voltage gains. As the closed-loop gain is increased, the larger
phase margin allows for larger capacitive loads with less peaking. Adding a series resistor with lower closed-loop gains accomplishes the same effect. For large capacitive loads, the
frequency response of the amplifier will be dominated by the
roll-off of the series resistor and the load capacitance.
2.60
2.55
2.50
2.45
2.40
Figure 38. AD8051/AD8052 200 mV Step Response:
C
= 50 pF
L
10000
VS = +5V
# 30%
F
P
CAPACITIVE LOAD 2
1000
100
10
OVERSHOOT
1
162
RS = 3V
RS = 0V
R
R
G
F
V
IN
100mV STEP
50V
345
A
– V/V
CL
R
S
V
OUT
C
L
Figure 39. AD8051/AD8052 Capacitive Load Drive vs.
Closed-Loop Gain
8
6
4
2
0
22
GAIN – dB
24
VS = +5V
26
G = +1
R
= 2kV
L
28
C
= 50pF
L
V
= 200mV p-p
O
210
0.1110100
FREQUENCY – MHz
500
Figure 37. AD8051/AD8052 Closed-Loop Frequency
Response: C
= 50 pF
L
1000
VS = +5V
# 30%
OVERSHOOT
RS = 10V
R
50V
RS = 0V
R
G
F
R
S
V
OUT
C
L
100
CAPACITIVE LOAD – pF
10
162345
V
IN
100mV STEP
ACL – V/V
Figure 40. AD8054 Capacitive Load Drive vs. Closed-Loop
Gain
Circuit Description
The AD8051/AD8052/AD8054 is fabricated on Analog Devices’
proprietary eXtra-Fast Complementary Bipolar (XFCB) process, which enables the construction of PNP and NPN transistors with similar f
s in the 2 GHz–4 GHz region. The process is
T
dielectrically isolated to eliminate the parasitic and latch-up
–12–
REV. B
Page 13
AD8051/AD8052/AD8054
problems caused by junction isolation. These features allow the
construction of high frequency, low distortion amplifiers with low
supply currents. This design uses a differential output input stage
to maximize bandwidth and headroom (see Figure 1). The smaller
signal swings required on the first stage outputs (nodes S1P, S1N)
reduce the effect of nonlinear currents due to junction capacitances
and improve the distortion performance. With this design har-
monic distortion of –80 dBc @ 1 MHz into 100 Ω with V
OUT
=
2 V p-p (Gain = +1) on a single 5 V supply is achieved.
The inputs of the device can handle voltages from –0.2 V below
the negative rail to within 1 V of the positive rail. Exceeding
these values will not cause phase reversal; however, the input
ESD devices will begin to conduct if the input voltages exceed
the rails by greater than 0.5 V. During this overdrive condition,
the output stays at the rail.
The rail-to-rail output range of the AD8051/AD8052/AD8054
is provided by a complementary common-emitter output stage.
High output drive capability is provided by injecting all output stage predriver currents directly into the bases of the output
devices Q8 and Q36. Biasing of Q8 and Q36 is accomplished by
I8 and I5, along with a common-mode feedback loop (not
shown). This circuit topology allows the AD8051/AD8052 to drive
45 mA of output current and the AD8054 to drive 30 mA of output current with the outputs within 0.5␣ V of the supply rails.
V
VINP
VINN
V
CC
R26
Q4
R2
R15
Q1
Q13
Q2
C7
EE
Q40
R5
V
SIP
I10
R39
Q5
EE
SIN
Q11
Q3
R21
I2I3
Q22
R3
Q25
Q39
Q51
R27
R23
Q7
Q21Q27
Q24Q47
I7
Q50
Q31
Q23
I11
I9
Q36
I5
V
EE
C3
V
OUT
C9
Q8
I8
V
CC
Figure 41. AD8051/AD8052 Simplified Schematic
to a minimum. Parasitic capacitance of less than 1 pF at the
inverting input can significantly affect high speed performance.
Stripline design techniques should be used for long signal traces
(greater than about 25 mm). These should be designed with a
characteristic impedance of 50 Ω or 75 Ω and be properly termi-
nated at each end.
Active Filters
Active filters at higher frequencies require wider bandwidth op
amps to work effectively. Excessive phase shift produced by
lower frequency op amps can significantly impact active filter
performance.
Figure 42 shows an example of a 2␣ MHz biquad bandwidth
filter that uses three op amps of an AD8054. Such circuits are
sometimes used in medical ultrasound systems to lower the
noise bandwidth of the analog signal before A/D conversion.
Please note that the unused amplifiers’ inputs should be tied to
ground.
R6
1kV
C1
50pF
R2
2kV
R1
3kV
V
IN
2
3
1
AD8054
R3
2kV
6
5
AD8054
R4
2kV
C2
50pF
R5
2kV
7
9
10
AD8054
13
12
8
V
OUT
14
Figure 42. 2␣ MHz Biquad Bandpass Filter Using AD8054
The frequency response of the circuit is shown in Figure 43.
0
210
220
APPLICATIONS
Layout Considerations
The specified high speed performance of the AD8051/AD8052/
AD8054 requires careful attention to board layout and component selection. Proper RF design techniques and low-parasitic
component selection are necessary.
The PCB should have a ground plane covering all unused portions of the component side of the board to provide a low impedance path. The ground plane should be removed from the
area near the input pins to reduce the parasitic capacitance.
Chip capacitors should be used for the supply bypassing. One
end should be connected to the ground plane and the other
within 3 mm of each power pin. An additional large (4.7␣ µF to
10 µF) tantalum electrolytic capacitor should be connected in
parallel, but not necessarily so close, to supply current for fast,
large signal changes at the output.
The feedback resistor should be located close to the inverting
input pin in order to keep the parasitic capacitance at this node
REV. B
–13–
GAIN – dB
230
240
10k100M100k1M10M
FREQUENCY – Hz
Figure 43. Frequency Response of 2␣ MHz Bandpass
Biquad Filter
A/D and D/A Applications
Figure 44 is a schematic showing the AD8051 used as a driver
for an AD9201, a 10-bit 20 MSPS dual A/D converter. This
converter is designed to convert I and Q signals in communication systems. In this application, only the I channel is being
driven. The I channel is enabled by applying a logic HIGH to
SELECT, Pin 27.
The AD8051 is running from a dual supply and is configured
for a gain of +2. The input signal is terminated in 50 Ω and
Page 14
AD8051/AD8052/AD8054
0.33mF
50V
+5V
AD8051
0.1mF
10mF
0.01mF
22V
1kV
22V
0.1mF
0.1mF
1kV
25V
0.1mF
10mF
15V
10mF
10mF0.1mF
1kV
0.1mF
22V
Figure 44. AD8051 Driving an AD9201, a 10-Bit 20 MSPS A/D Converter
applied to the noninverting input of the AD8051. The amplifier
output is 2 V p-p, which is the maximum input range of the
AD9201. The 22 Ω series resistor limits the maximum current
that flows and helps to lower the distortion of the A/D.
The AD9201 has differential inputs for each channel. These are
designated the A and B inputs. The B inputs of each channel are
connected to VREF (Pin 8) which supplies a positive reference
of 2.5 V. Each of the B inputs has a small low pass filter that
also helps to reduce distortion.
The output of the op amp is ac coupled into INA-I (Pin 2) via
two parallel capacitors to provide good high frequency and low
frequency coupling. The 1 kΩ resistor references the signal to
VREF that is applied to INB-I. Thus, INA-I will swing both
22V
0.1mF
22V
10pF
10pF
0.1mF10mF
0.1mF10mF0.1mF
10pF
SLEEP
INA-I
INB-I
REFT-I
REFB-I
AVSS
REFSENSE
V
REF
AVDD
REFB-Q
REFT-Q
INB-Q
AD9201
CLK
SELECT
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DVDD
DVSS
1V
DD
DATA OUT
15V
10mF0.1mF
INA-Q
10pF
THREE–STATE
positive and negative with respect to the bias voltage applied to
INB-I.
With the sampling clock running at 20 MSPS, the A/D output
was analyzed with a digital analyzer. Two input frequencies
were used, 1 MHz and 9.5 MHz, which is just short of the
Nyquist frequency. These signals were well filtered to minimize
any harmonics.
Figure 45 shows the FFT response of the A/D for the case of
1 MHz analog input. The SFDR is 71.66 dB and the A/D is
producing 8.8 ENOB (effective number of bits). When the
analog frequency was raised to 9.5 MHz, the SFDR was reduced to 60.18 dB and the A/D operated with 8.46 ENOBs as
shown in Figure 46. The inclusion of the AD8051 in the circuit
had no worsening of the distortion performance of the AD9201.
Synchronizing pulses are sometimes carried on video signals so
as not to require a separate channel to carry the synchronizing
information. However, for some functions, like A/D conversion,
it is not desirable to have the sync pulses on the video signal.
These pulses will reduce the dynamic range of the video signal
and do not provide any useful information for such a function.
A sync stripper will remove the synchronizing pulses from a
video signal while passing all the useful video information. Figure 47 shows a practical single supply circuit that uses only a
single AD8051. It is capable of directly driving a reverse terminated video line.
VIDEO WITHOUT SYNC
+
R2
1kV
0.1mF
10mF
100V
GROUND
TO A/D
V
BLANK
GROUND
VIDEO WITH SYNC
V
IN
(OR 2 3 V
+0.8V
R1
1kV
BLANK
+0.4V
AD8051
+3V OR +5V
)
Figure 47. Sync Stripper
The video signal plus sync is applied to the noninverting input
with the proper termination. The amplifier gain is set equal to
two via the two 1 kΩ resistors in the feedback circuit. A bias
voltage must be applied to R1 in order that the input signal has
the sync pulses stripped at the proper level.
The blanking level of the input video pulse is the desired place
to remove the sync information. This level is multiplied by two
by the amplifier. This level must be at ground at the output in
order for the sync stripping action to take place. Since the gain
of the amplifier from the input of R1 to the output is –1, a volt-
age equal to 2 × V
must be applied to make the blanking
BLANK
level come out at ground.
Single Supply Composite Video Line Driver
Many composite video signals have their blanking level at
ground and have video information that is both positive and
negative. Such signals require dual supply amplifiers to pass
them. However, by ac level shifting a single supply amplifier can
be used to pass these signals. The following complications may
arise from such techniques.
Signals of bounded peak-to-peak amplitude that vary in duty
cycle require larger dynamic swing capacity than their (bounded)
peak to peak amplitude after they are ac coupled. As a worst
case, the dynamic signal swing will approach twice the peakto-peak value. The two conditions that define the maximum
dynamic wing requirements are a signal that is mostly low, but
goes high with a duty cycle that is a small fraction of a percent.
The opposite condition defines the other extreme.
The worst case of composite video is not quite this demanding.
One bounding condition is a signal that is mostly black for an
entire frame, but has a white (full amplitude) minimum width
spike at least once in a frame.
The other extreme is for a full white video signal. The blanking
intervals and sync tips of such a signal will have negative-going
excursions is compliance with the composite video specifications. The combination of horizontal and vertical blanking intervals limit such a signal to being at the highest (white) level for a
maximum of about 75% of the time.
As a result of the duty cycles between the two extremes presented above, a 1 V p-p composite video signal that is multiplied
by a gain of two requires about 3.2 V p-p of dynamic voltage
swing at the output for an op amp to pass a composite video
signal of arbitrary varying duty cycle without distortion.
Some circuits use a sync tip clamp to hold the sync tips at a
relatively constant level in order to lower the amount of dynamic
signal swing required. However, these circuits can have artifacts
like sync tip compression unless they are driven by a source with
a very low output impedance. The AD8051/AD8052/AD8054
have adequate signal swing when running on a single +5 V
supply to handle an ac coupled composite video signal.
The input to the circuit in Figure 48 is a standard composite
(1 V p-p) video signal that has the blanking level at ground. The
input network level shifts the video signal by means of ac coupling. The noninverting input of the op amp is biased to half of
the supply voltage.
The feedback circuit provides unity gain for the dc biasing of the
input, and provides a gain of two for any signals that are in the
video bandwidth. The output is ac coupled and terminated to
drive the line.
The capacitor values were selected for providing minimum “tilt”
or field time distortion of the video signal. These values would
be required for video that is considered to be studio or broadcast quality. However, if a lower consumer grade of video,
sometimes referred to as “consumer video” is all that is desired,
the values and the cost of the capacitors can be reduced by as
much as a factor of five with minimum visible degradation in the
picture.
+5V
4.99kV
+
1kV
10mF
R
G
10mF
AD8051
220mF
R
1kV
0.1mF
F
+
1000mF
+
0.1mF
10mF
R
75V
BT
V
OUT
R
L
75V
COMPOSITE
VIDEO
IN
75V
R
T
4.99kV
47mF
+
Figure 48. Single Supply Composite Video Line Driver
REV. B
–15–
Page 16
AD8051/AD8052/AD8054
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
0.1574 (4.00)
0.1497 (3.80)
0.0098 (0.25)
0.0040 (0.10)
SEATING
PLANE
0.122 (3.10)
0.114 (2.90)
0.006 (0.15)
0.002 (0.05)
SEATING
PLANE
0.1968 (5.00)
0.1890 (4.80)
8
PIN 1
0.0500
(1.27)
BSC
0.122 (3.10)
0.114 (2.90)
8
1
PIN 1
0.0256 (0.65) BSC
0.120 (3.05)
0.112 (2.84)
0.018 (0.46)
0.008 (0.20)
8-Lead SOIC
(SO-8)
5
0.2440 (6.20)
41
0.2284 (5.80)
0.0688 (1.75)
0.0532 (1.35)
0.0192 (0.49)
0.0138 (0.35)
0.0098 (0.25)
0.0075 (0.19)
8-Lead SOIC
(RM-8)
5
0.199 (5.05)
0.187 (4.75)
4
0.043 (1.09)
0.037 (0.94)
0.011 (0.28)
0.003 (0.08)
0.0196 (0.50)
0.0099 (0.25)
8°
0°
0.0500 (1.27)
0.0160 (0.41)
0.120 (3.05)
0.112 (2.84)
33°
27°
x 45°
0.028 (0.71)
0.016 (0.41)
0.1574 (4.00)
0.1497 (3.80)
0.0098 (0.25)
0.0040 (0.10)
SEATING
PLANE
0.177 (4.50)
0.169 (4.30)
0.006 (0.15)
0.002 (0.05)
SEATING
PLANE
0.3444 (8.75)
0.3367 (8.55)
148
PIN 1
0.0500
0.0192 (0.49)
(1.27)
0.0138 (0.35)
BSC
14-Lead TSSOP
0.201 (5.10)
0.193 (4.90)
148
1
PIN 1
0.0118 (0.30)
0.0256
(0.65)
0.0075 (0.19)
BSC
14-Lead SOIC
(R-14)
0.2440 (6.20)
71
0.2284 (5.80)
0.0688 (1.75)
0.0532 (1.35)
0.0098 (0.25)
0.0075 (0.19)
(RU-14)
0.256 (6.50)
0.246 (6.25)
7
0.0433
(1.10)
MAX
0.0079 (0.20)
0.0035 (0.090)
0.0196 (0.50)
0.0099 (0.25)
8°
0°
0.0500 (1.27)
0.0160 (0.41)
8°
0°
C3139b–0–9/99
x 45°
0.028 (0.70)
0.020 (0.50)
0.0709 (1.800)
0.0590 (1.500)
0.0512 (1.300)
0.0354 (0.900)
0.0590 (0.150)
0.0000 (0.000)
PIN 1
5-Lead Plastic Surface Mount
(RT-5)
0.1220 (3.100)
0.1063 (2.700)
4 5
0.1181 (3.000)
1 3
2
0.0748 (1.900)
REF
0.0197 (0.500)
0.0118 (0.300)
0.0984 (2.500)
0.0374 (0.950) REF
0.0571 (1.450)
0.0354 (0.900)
SEATING
PLANE
10°
0°
0.0079 (0.200)
0.0035 (0.090)
0.0236 (0.600)
0.0039 (0.100)
–16–
PRINTED IN U.S.A.
REV. B
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