Low Distortion 750 MHz
1
2
3
4
8
7
6
5
NC = NO CONNECT
AD9630
***
NC
**
INPUT
+V
S
NC
–V
S
OUTPUT
NOTE: FOR BEST SETTLING TIME PERFORMANCE USE
OPTIONAL POWER SUPPLIES. ALL SPECIFICATIONS
ARE BASED ON USING SINGLE 6V
S
CONNECTIONS,
EXCEPT FOR SETTLING TIME TO 0.02% AND SMALL
SIGNAL S21. CONSULT THE FACTORY FOR VERSIONS
WITH OPTIONAL POWER SUPPLY PINS DISCONNECTED
INTERNAL TO THE PACKAGE.
**OPTIONAL +V
S
***OPTIONAL –V
S
a
FEATURES
Excellent Gain Accuracy: 0.99 V/V
Wide Bandwidth: 750 MHz
Slew Rate: 1200 V/s
Low Distortion
–65 dBc @ 20 MHz
–80 dBc @ 4.3 MHz
Settling Time
5 ns to 0.1%
8 ns to 0.02%
Low Noise: 2.4 nV/√Hz
Improved Source for CLC-110
APPLICATIONS
IF/Communications
Impedance Transformations
Drives Flash ADCs
Line Driving
GENERAL DESCRIPTION
The AD9630 is a monolithic buffer amplifier that utilizes a
patented, innovative, closed-loop design technique to achieve
exceptional gain accuracy, wide bandwidth, and low distortion.
Slew rate limiting has been overcome as indicated by the
1200 V/µs slew rate; this improvement allows the user greater
flexibility in wideband and pulse applications. The second harmonic distortion terms for an analog input tone of 4.3 MHz
and 20 MHz are –80 dBc and –66 dBc, respectively. Clearly,
the AD9630 establishes a new standard by combining outstanding dc and dynamic performance in one part.
Closed-Loop Buffer Amp
AD9630*
PIN CONFIGURATION
The large signal bandwidth, low distortion over frequency, and
drive capabilities of the AD9630 make the buffer an ideal flash
ADC driver. The AD9630 provides better signal fidelity than
many of the flash ADCs that it has been designed to drive.
Other applications that require increased current drive at unity
voltage gain (such as cable driving) benefit from the AD9630’s
performance.
The AD9630 is available in plastic DIP (N) and SOIC (R).
*Protected under U.S. patent numbers 5,150,074 and 5,537,079.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
Fax: 617/326-8703 © Analog Devices, Inc., 1999
AD9630–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
(unless otherwise noted, ⴞVS = ⴞ5 V; RIN = 50 ⍀, R
= 100 ⍀)
LOAD
Test AD9630AN/AR
Parameter Conditions Temp Level Min Typ Max Units
DC SPECIFICATIONS
Output Offset Voltage +25°CI–8±3+8mV
Offset Voltage TC Full IV –40 ±8 +40 µV/°C
Input Bias Current +25°C I –25 ±2 +25 µA
Bias Current TC Full IV –100 ±20 +100 nA/°C
Input Resistance +25 to T
T
MIN
MAX
II 300 450 kΩ
VI 150 250 kΩ
Input Capacitance +25°CV 1.0 pF
Gain V
= 2 V p-p +25 to T
OUT
= 2 V p-p T
V
OUT
MAX
MIN
II 0.983 0.990 V/V
VI 0.980 0.985 V/V
Output Voltage Range Full VI +3.2 ±3.6 –3.2 V
Output Current (50 Ω Load) +25 to T
T
MIN
MAX
II 50 mA
VI 40 mA
Output Impedance At DC +25°CV 0.6 Ω
PSRR ∆V
= ±5% Full VI 44 55 dB
S
DC Nonlinearity ±2 V Full Scale +25°C V 0.03 %
FREQUENCY DOMAIN
Bandwidth (–3 dB)
Small Signal V
Large Signal V
≤ 0.7 V p-p T
O
≤ 0.7 V p-p T
V
O
= 5 V p-p T
O
= 5 V p-p T
V
O
to +25 II 400 750 MHz
MIN
MAX
to +25 V 120 MHz
MIN
MAX
II 330 550 MHz
V 105 MHz
Output Peaking ≤200 MHz Full II 0.4 1.2 dB
Output Rolloff ≤200 MHz Full II 0 0.3 dB
Group Delay DC to 150 MHz +25°CV 0.7 ns
Linear Phase Deviation DC to 150 MHz +25°C V 0.7 Degrees
2nd Harmonic Distortion 2 V p-p; 4.3 MHz Full IV –80 –73 dBc
2 V p-p; 20 MHz Full IV –66 –58 dBc
2 V p-p; 50 MHz Full II –52 –43 dBc
3rd Harmonic Distortion 2 V p-p; 4.3 MHz Full IV –86 –79 dBc
2 V p-p; 20 MHz Full IV –75 –68 dBc
2 V p-p; 50 MHz T
2 V p-p; 50 MHz T
to +25 II –47 –41 dBc
MIN
MAX
II –46 –40 dBc
Spectral Input Noise Voltage 10 MHz +25°C V 2.4 nV/√Hz
Integrated Output Noise 100 kHz – 200 MHz +25°CV 32 µV
TIME DOMAIN
Slew Rate V
Rise/Fall Time V
Overshoot Amplitude V
= 5 V Step +25°C IV 700 1200 V/µs
OUT
= 1 V Step +25°CIV 1.11.7ns
OUT
= 1 V Step T
V
OUT
= 5 V Step +25°CIV 4.25.7ns
V
OUT
= 5 V Step T
V
OUT
= 2 V Step Full IV 2 12 %
OUT
MIN
MIN
to T
to T
MAX
MAX
IV 1.3 1.9 ns
IV 5.0 6.5 ns
Settling Time
To 0.1% V
To 0.02%
4
= 2 V Step T
OUT
= 2 V Step T
V
OUT
V
= 2 V Step T
OUT
= 2 V Step T
V
OUT
to +25 IV 6 10 ns
MIN
MAX
to +25 IV 8 ns
MIN
MAX
IV 7 12 ns
V12ns
Differential Gain 4.4 MHz +25°C V 0.015 %
Differential Phase 4.4 MHz +25°C V 0.025 Degree
SUPPLY CURRENTS
(+IS)V
V
CC
VEE (–IS)V
NOTES
1
Short-term settling with 50 Ω source impedance.
Specifications subject to change without notice.
= +5 V Full II 19 26 mA
CC
= –5 V Full II 19 26 mA
EE
–2–
REV. B
AD9630
1
2
3
4
8
7
6
5
TOP VIEW
(Not to Scale)
NC = NO CONNECT
AD9630
NC
NC
NC
NC
100V
(5%, 0.25W)
24V
(5%, 0.25W)
+5V
–5.2V
0.1mF
0.1mF
CL – pF
50
40
0
0
10020
R
SERIES
– V
40 60 80
30
20
10
7
R
S
C
L
200V
"R"
NO R
S
NEEDED
WHEN
C
L
< 7pF;
FOR
C
L
> 30pF, "R"
CAN
BE OMITTED
WARNING!
ESD SENSITIVE DEVICE
ABSOLUTE MAXIMUM RATINGS
Supply Voltages (±VS) . . . . . . . . . . . . . . . . . . . . . . . . . . . ±7 V
Continuous Output Current
2
. . . . . . . . . . . . . . . . . . . . . 70 mA
1
Temperature Range over Which Specifications Apply
°
AD9630AN/AR . . . . . . . . . . . . . . . . . . . . . –40
C to +85°C
Lead Soldering Temperature (10 sec) . . . . . . . . . . . . . +300°C
Storage Temperature
AD9630AN/AR . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Junction Temperature
3
AD9630AN/AR . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150°C
NOTES
1
Absolute maximum ratings are limiting values to be applied individually, and
beyond which the serviceability of the circuit may be impaired. Functional
operability is not necessarily implied. Exposure to absolute maximum rating
conditions for an extended period of time may affect device reliability.
2
Output is short-circuit protected to ground, but not to supplies. Prolonged short
circuit to ground may affect device reliability.
3
Typical thermal impedances (part soldered onto board): Plastic DIP (N): θ
110°C/W; θJC = 30°C/W; SOIC (R): θJA = 155°C/W; θJC = 40°C/W.
=
JA
ORDERING GUIDE
Temperature Package Package
Model Range Description Option
AD9630AN –40°C to +85°C 8-Lead Plastic DIP N-8
AD9630AR –40°C to +85°C 8-Lead SOIC SO-8
AD9630AR-REEL –40°C to +85°C13" Tape and Reel SO-8
EXPLANATION OF TEST LEVELS
Test Level
I 100% Production tested.
II 100% Production tested at +25°C and sample tested at
specified temperatures. AC testing of AN and AR grades
done on sample basis only.
III Sample tested only.
IV Parameter is guaranteed by design and characterization
testing.
V Typical value.
VI S Versions are 100% production tested at temperature
extremes. Other grades are sample tested at extremes.
AD9630 Burn-In Circuit
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 AD9630 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.
THEORY OF OPERATION
The AD9630 is a wide-bandwidth, closed-loop, unity-gain
buffer that makes use of a new voltage-feedback architecture.
This architecture brings together wide bandwidth and high slew
rate along with exceptional dc linearity. Most previous widebandwidth buffers achieved their bandwidth by utilizing an
open-loop topology which sacrificed both dc linearity and fre-
Parasitic or load capacitance (>7 pF) connected directly to the
AD9630 output will result in frequency peaking. A small series
resistor (R
) connected between the buffer output and capaci-
S
tive load will negate this effect. Figure 1 shows the optimal value
as a function of CL to obtain the flattest frequency re-
of R
S
sponse. Figure 2 illustrates frequency response for various
capacitive loads utilizing the recommended R
.
S
quency distortion when driven into low load impedances. The
design’s high loop correction factor radically improves dc linearity and distortion characteristics without diminishing
bandwidth. This, in combination with high slew rate, results in
exceptionally low distortion over a wide frequency range.
The AD9630 is an excellent choice to drive high speed and high
resolution analog-to-digital converters. Its output stage is designed to drive high speed flash converters with minimal or no
series resistance. A current booster built into the output driver
helps to maintain low distortion.
REV. B
Figure 1. Recommended RS vs. C
L
–3–