Analog Devices AD8047 8 a Datasheet

250 MHz, General Purpose

Voltage Feedback Op Amps

AD8047/AD8048

FEATURES
Wide Bandwidth AD8047, G = +1 AD8048, G = +2

Small Signal 250 MHz 260 MHz
Large Signal (2 V p-p) 130 MHz 160 MHz

5.8 mA Typical Supply Current
Low Distortion, (SFDR) Low Noise

–66 dBc Typ @ 5 MHz
–54 dBc Typ @ 20 MHz

5.2 nV/√Hz (AD8047), 3.8 nV/√Hz (AD8048) Noise

Drives 50 pF Capacitive Load
High Speed

Slew Rate 750 V/s (AD8047), 1000 V/s (AD8048)
Settling 30 ns to 0.01%, 2 V Step

3 V to 6 V Supply Operation

APPLICATIONS
Low Power ADC Input Driver
Differential Amplifiers
IF/RF Amplifiers
Pulse Amplifiers
Professional Video
DAC Current to Voltage Conversion
Baseband and Video Communications
Pin Diode Receivers
Active Filters/Integrators

PRODUCT DESCRIPTION

The AD8047 and AD8048 are very high speed and wide band­width amplifiers. The AD8047 is unity gain stable. The AD8048 is
stable at gains of two or greater. The AD8047 and AD8048,
which utilize a voltage feedback architecture, meet the require­ments of many applications that previously depended on current
feedback amplifiers.

A proprietary circuit has produced an amplifier that combines
many of the best characteristics of both current feedback and
voltage feedback amplifiers. For the power (6.6 mA max), the
AD8047 and AD8048 exhibit fast and accurate pulse response
(30 ns to 0.01%) as well as extremely wide small signal and large
signal bandwidth and low distortion. The AD8047 achieves
–54 dBc distortion at 20 MHz, 250 MHz small signal, and
130 MHz large signal bandwidths.

FUNCTIONAL BLOCK DIAGRAM

8-Pin Plastic PDIP (N)

and SOIC (R) Packages

NC

–INPUT

+INPUT

–V

1

2

3

4

S

NC = NO CONNECT

AD8047/

AD8048

(TOP VIEW)

8

7

6

5

NC

+V

S

OUTPUT

NC

The AD8047 and AD8048’s low distortion and cap load drive
make the AD8047/AD8048 ideal for buffering high speed ADCs.
They are suitable for 12-bit/10 MSPS or 8-bit/60 MSPS ADCs.
Additionally, the balanced high impedance inputs of the voltage
feedback architecture allow maximum flexibility when designing
active filters.

The AD8047 and AD8048 are offered in industrial (–40°C to
+85°C) temperature ranges and are available in 8-lead PDIP
and SOIC packages.

1V

5ns

Figure 1. AD8047 Large Signal Transient Response,
VO = 4 V p-p, G = +1

REV. A

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 companies.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

AD8047/AD8048–SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

(VS = 5 V, R

= 100 , AV = 1 (AD8047), AV = 2 (AD8048), unless otherwise noted.)

LOAD

AD8047A AD8048A

Parameter Conditions Min Typ Max Min Typ Max Unit

DYNAMIC PERFORMANCE

Bandwidth (–3 dB)

Small Signal V
Large Signal

1

Bandwidth for 0.1 dB Flatness V

≤ 0.4 V p-p 170 250 180 260 MHz

OUT

V

= 2 V p-p 100 130 135 160 MHz

OUT

= 300 mV p-p

OUT

AD8047, RF=0 Ω;

= 200 Ω 35 50 MHz

F

Slew Rate, Average +/– V
Rise/Fall Time V

AD8048, R

= 4 V Step 475 750 740 1000 V/µs

OUT

= 0.5 V Step 1.1 1.2 ns

OUT

= 4 V Step 4.3 3.2 ns

V

OUT

Settling Time

To 0.1% V
To 0.01% V

= 2 V Step 13 13 ns

OUT

= 2 V Step 30 30 ns

OUT

HARMONIC/NOISE PERFORMANCE

Second Harmonic Distortion 2 V p-p; 20 MHz –54 –48 dBc

= 1 kΩ –64 –60 dBc

R

L

Third Harmonic Distortion 2 V p-p; 20 MHz –60 –56 dBc

= 1 kΩ –61 –65 dBc

R

L

Input Voltage Noise f = 100 kHz 5.2 3.8 nV/√Hz
Input Current Noise f = 100 kHz 1.0 1.0 pA/√Hz
Average Equivalent Integrated

Input Noise Voltage 0.1 MHz to 10 MHz 16 11 µV rms

Differential Gain Error (3.58 MHz) R

= 150 Ω, G = +2 0.02 0.01 %

L

Differential Phase Error (3.58 MHz) RL = 150 Ω, G = +2 0.03 0.02 Degree

2,

DC PERFORMANCE

Input Offset Voltage

RL = 150 Ω

3

T

MIN

to T

MAX

13 13 mV

44mV

Offset Voltage Drift ±5 ±5 µV/°C
Input Bias Current 1 3.5 1 3.5 µA

T

MIN

to T

MAX

6.5 6.5 µA

Input Offset Current 0.5 2 0.5 2 µA

Common-Mode Rejection Ratio V
Open-Loop Gain V

to T

T

T

MIN

CM

OUT

MIN

MAX

= ±2.5 V 74 80 74 80 dB

= ±2.5 V 58 62 65 68 dB
to T

MAX

54 56 dB

33µA

INPUT CHARACTERISTICS

Input Resistance 500 500 kΩ
Input Capacitance 1.5 1.5 pF
Input Common-Mode Voltage Range ±3.4 ±3.4 V

OUTPUT CHARACTERISTICS

Output Voltage Range, RL = 150 Ω±2.8 ±3.0 ±2.8 ±3.0 V
Output Current 50 50 mA
Output Resistance 0.2 0.2 Ω
Short-Circuit Current 130 130 mA

POWER SUPPLY

Operating Range ±3.0 ± 5.0 ±6.0 ± 3.0 ±5.0 ±6.0 V
Quiescent Current 5.8 6.6 5.9 6.6 mA

T

MIN

to T

MAX

7.5 7.5 mA

Power Supply Rejection Ratio 72 78 72 78 dB

NOTES

1

See Absolute Maximum Ratings and Theory of Operation sections.

2

Measured at AV = 50.

3

Measured with respect to the inverting input.

Specifications subject to change without notice.

REV. A–2–

AD8047/AD8048

ABSOLUTE MAXIMUM RATINGS

1

Supply Voltage, (+VS) – (–VS) . . . . . . . . . . . . . . . . . . . . 12.6 V

Voltage Swing × Bandwidth Product

AD8047 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 V-MHz

AD8048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 V-MHz

Internal Power Dissipation

2

Plastic Package (N) . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 W

Small Outline Package (R) . . . . . . . . . . . . . . . . . . . . . 0.9 W

Input Voltage (Common Mode) . . . . . . . . . . . . . . . . . . . . ±V

S

Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . ± 1.2 V

Output Short-Circuit Duration . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . .Observe Power Derating Curves

Storage Temperature Range (N, 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 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 PDIP Package, ␪JA = 90°C/W; 8-Lead
SOIC Package, ␪JA = 140°C/W

METALLIZATION PHOTOS

Dimensions shown in inches and (mm)

Connect Substrate to –VS.

AD8047

+V

S

MAXIMUM POWER DISSIPATION

The maximum power that can be safely dissipated by these devices
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 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 temperature of 175°C for an extended period can
result in device failure.

While the AD8047 and AD8048 are internally short circuit
protected, this may not be sufficient to guarantee that the maxi­mum junction temperature (150°C) is not exceeded under all
conditions. To ensure proper operation, it is necessary to observe
the maximum power derating curves.

2.0

1.5

1.0

0.5

8-PIN PDIP PACKAGE

8-PIN SOIC PACKAGE

TJ = +150C

–IN

–IN

+IN

+IN

0.044
(1.13)

AD8048

+V

S

0.044
(1.13)

MAXIMUM POWER DISSIPATION (W)

0

–50 80

–40

0.045
(1.14)

V

OUT

Figure 2. Plot of Maximum Power Dissipation vs.

0 10 –10 –20 –30 20 30 40 50 60 70

AMBIENT TEMPERATURE (C)

90

Temperature

ORDERING GUIDE

–V

S

Temperature Package Package

Model Range Description Option*

AD8047AN –40°C to +85°CPDIP N-8
AD8047AR –40°C to +85°C SOIC R-8
AD8047AR-REEL –40°C to +85°C SOIC R-8
AD8047AR-REEL7 –40°C to +85°C SOIC R-8
AD8048AN –40°C to +85°CPDIP N-8

0.045

(1.14)

V

OUT

–V

S

AD8048AR –40°C to +85°C SOIC R-8
AD8048AR-REEL –40°C to +85°C SOIC R-8
AD8048AR-REEL7 –40°C to +85°C SOIC R-8

*N = PDIP, R= SOIC

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
AD8047/AD8048 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.

REV. A

–3–

AD8047/AD8048–Typical Performance Characteristics

T

T

10F

S

0.1F

7

= 100

R

L

V

OU

6

0.1F

4

10F

S

PULSE

GENERATOR

TR/TF = 500ps

V

IN

RT = 49.9

+V

2

AD8047

3

–V

TPC 1. AD8047 Noninverting Configuration, G = +1

PULSE

GENERATOR

TR/TF = 500ps

V

IN

RT = 66.5

100

TPC 4. AD8047 Inverting Configuration, G = –1

R

F

+V

R

IN

2

AD8047

3

–V

10F

S

0.1F

7

6

0.1F

4

10F

S

V

OU

RL = 100

1V

5ns

TPC 2. AD8047 Large Signal Transient Response;
VO = 4 V p-p, G = +1

100mV

5ns

TPC 3. AD8047 Small Signal Transient Response;
VO = 400 mV p-p, G = +1

1V

5ns

TPC 5. AD8047 Large Signal Transient Response;
VO = 4 V p-p, G = –1, RF = RIN = 200

100mV

Ω

5ns

TPC 6. AD8047 Small Signal Transient Response;
VO = 400 mV p-p, G = –1, RF = R

= 200

IN

Ω

REV. A–4–

R

F

PULSE

GENERATOR

TR/TF = 500ps

R

V

IN

= 49.9

R

T

+V

IN

2

AD8048

3

–V

10F

S

0.1F

7

V

R

L

OUT

= 100

6

0.1F

4

10F

S

TPC 7. AD8048 Noninverting Configuration, G = +2

AD8047/AD8048

R

F

PULSE

GENERATOR

TR/TF = 500ps

V

IN

RS = 100

R

IN

RT = 66.5

+V

2

AD8048

3

–V

TPC 10. AD8048 Inverting Configuration, G= –1

10F

S

0.1F

7

6

0.1F

4

10F

S

V

OUT

RL = 100

5ns1V

TPC 8. AD8048 Large Signal Transient Response;
VO = 4 V p-p, G = +2, RF = RIN = 200

100mV

Ω

5ns

TPC 9. AD8048 Small Signal Transient Response;
VO = 400 mV p-p, G = +2, RF = RIN = 200

Ω

1V

5ns

TPC 11. AD8048 Large Signal Transient Response;
VO = 4 V p-p, G = –1, RF = RIN = 200

100mV

Ω

5ns

TPC 12. AD8048 Small Signal Transient Response;
VO = 400 mV p-p, G = –1, RF = R

= 200

IN

Ω

REV. A

–5–