ANALOG DEVICES AD548 Service Manual
Precision, Low Power
a
FEATURES
Enhanced Replacement for LF441 and TL061
DC Performance:
200 A max Quiescent Current
10 pA max Bias Current, Warmed Up (AD548C)
250 V max Offset Voltage (AD548C)
2 V/C max Drift (AD548C)
2 V p-p Noise, 0.1 Hz to 10 Hz
AC Performance:
1.8 V/s Slew Rate
1 MHz Unity Gain Bandwidth
Available in Plastic and Hermetic Metal Can Packages
and in Chip Form
Available in Tape and Reel in Accordance with
EIA-481A Standard
MIL-STD-883B Parts Available
Dual Version Available: AD648
Surface-Mount (SOIC) Package Available
PRODUCT DESCRIPTION
The AD548 is a low power, precision monolithic operational
amplifier. It offers both low bias current (10 pA max, warmed
up) and low quiescent current (200 µA max) and is fabricated
with ion-implanted FET and laser wafer trimming technologies.
Input bias current is guaranteed over the AD548’s entire
common-mode voltage range.
The economical J grade has a maximum guaranteed input offset
voltage of less than 2 mV and an input offset voltage drift of less
than 20 µV/°C. This level of dc precision is achieved utilizing
Analog’s laser wafer drift trimming process. The combination of
low quiescent current and low offset voltage drift minimizes
changes in input offset voltage due to self-heating effects.
The AD548 is recommended for any dual supply op amp application requiring low power and excellent dc and ac performance.
In applications such as battery-powered, precision instrument
front ends and CMOS DAC buffers, the AD548’s excellent combination of low input offset voltage and drift, low bias current,
and low 1/f noise reduces output errors. High common-mode
rejection (82 dB, min on the “B” grade) and high open-loop
gain ensures better than 12-bit linearity in high impedance,
buffer applications.
The AD548 is pinned out in a standard op amp configuration
and is available in three performance grades. The AD548J and
AD548K are rated over the commercial temperature range of
0°C to 70°C. The AD548B is rated over the industrial temperature range of –40°C to +85°C.
The AD548 is available in an 8-lead plastic mini-DIP and
surface-mount (SOIC) packages.
BiFET Op Amp
AD548
CONNECTION DIAGRAMS
Plastic Mini-DIP (N) Package
and
SOIC (R)Package
OFFSET NULL
INVERTING
NONINVERTING
NOTE: PIN 4 CONNECTED TO CASE
NC = NO CONNECT
PRODUCT HIGHLIGHTS
INPUT
INPUT
V–
1
2
3
4
1
AD548
TOP VIEW
10k
VOS TRIM
TOP VIEW
1. A combination of low supply current, excellent dc and ac
performance and low drift makes the AD548 the ideal op
amp for high performance, low power applications.
2. The AD548 is pin compatible with industry standard op
amps such as the LF441, TL061, and AD542, enabling
designers to improve performance while achieving a reduction
in power dissipation of up to 85%.
3. Guaranteed low input offset voltage (2 mV max) and drift
(20 µV/°C max) for the AD548J are achieved utilizing
Analog Devices’ laser drift trimming technology, eliminating
the need for external trimming.
4. Analog Devices specifies each device in the warmed-up
condition, insuring that the device will meet its published
specifications in actual use.
5. A dual version, the AD648, is also available.
6. Enhanced replacement for LF441 and TL061.
8
7
6
5
5
–15V
4
NC
V+
OUTPUT
OFFSET
NULL
REV. D
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2002
AD548–SPECIFICATIONS
(@ 25C and VS = 15 V dc unless otherwise noted.)
AD548J AD548K/B
Parameter Min Typ Max Min Typ Max Unit
INPUT OFFSET VOLTAGE
1
Initial Offset 0.75 2.0 0.3 0.5 mV
T
MIN
to T
MAX
3.0/3.0/3.0 0.7/0.8 mV
vs. Temperature 20 5 µV/°C
vs. Supply 80 86 dB
vs. Supply, T
MIN
to T
MAX
76/76/76 80 dB
Long-Term Offset Stability 15 15 µV/Month
INPUT BIAS CURRENT
Either Input2, VCM = 0 5 20 3 10 pA
Either Input
2
at T
, VCM = 0 0.45/1.3/20 0.25/0.65 nA
MAX
Max Input Bias Current Over
Common-Mode Voltage Range 30 15 pA
Offset Current, V
Offset Current at T
INPUT IMPEDANCE
Differential 1 × 10
= 0 5 10 2 5 pA
CM
MAX
0.25/0.65/10 0.15/0.35 nA
12
储31 × 1012储3 Ω储pF
Common Mode 3 × 1012储33 × 1012储3 Ω储pF
INPUT VOLTAGE RANGE
Differential
3
±20 ±20 V
Common Mode ±11 ±12 ±11 ±12 V
Common-Mode Rejection
= ±10 V 76 90 82 92 dB
V
CM
to T
T
MIN
V
= ±11 V 70 84 76 86 dB
CM
T
MIN
to T
MAX
MAX
76/76/76 90 82 92 dB
70/70/70 84 76 86 dB
INPUT VOLTAGE NOISE
Voltage 0.1 Hz to 10 Hz 2 2 µV p-p
f = 10 Hz 80 80 nV/√Hz
f = 100 Hz 40 40 nV/√Hz
f = 1 kHz 30 30 nV/√Hz
f = 10 kHz 30 30 nV/√Hz
INPUT CURRENT NOISE
f = 1 kHz 1.8 1.8 fA/√Hz
FREQUENCY RESPONSE
Unity Gain, Small Signal 0.8 1.0 0.8 1.0 MHz
Full Power Response 30 30 kHz
Slew Rate, Unity Gain 1.0 1.8 1.0 1.8 V/µs
Settling Time to ±0.01% 8 8 µs
OPEN LOOP GAIN
VO = ±10 V, RL ≥ 10 kΩ 300 1000 300 1000 3V/mV
to T
T
MIN
V
= ±10 V, RL ≥ 5 kΩ 150 500 150 500 V/mV
O
T
to T
MIN
, RL ≥ 10 kΩ 300/300/300 700 300 700 V/mV
MAX
, RL ≥ 5 kΩ 150/150/150 300 150 300 V/mV
MAX
OUTPUT CHARACTERISTICS
Voltage @ R
T
MIN
Voltage @ R
T
MIN
≥ 10 kΩ, ±12 ±13 ±12 ±13 V
L
to T
MAX
≥ 5 kΩ, ±11 ±12.3 ±11 ±12.3 V
L
to T
MAX
±12/± 12/±12 ±12
±11/± 11/±11 ±11
Short Circuit Current 15 15 mA
–2–
REV. D
SPECIFICATIONS (continued)
AD548J AD548K/B
Min Typ Max Min Typ Max Unit
POWER SUPPLY
Rated Performance ±15 ±15 V
Operating Range ±4.5 ±18 ±4.5 ± 18 V
Quiescent Current 170 200 170 200 µA
TEMPERATURE RANGE
Operating, Rated Performance
Commercial (0°C to 70°C) AD548J AD548K
Industrial (–40°C to +85°C) AD548A AD548B
Military (–55°C to +125°C) AD548S
PACKAGE OPTIONS
SOIC (R-8) AD548JR AD548KR
Plastic (N-8) AD548JN
4
AD548KN
Tape and Reel AD548JR-REEL AD548KR-REEL
NOTES
1
Input Offset Voltage specifications are guaranteed after five minutes of operation at TA = 25°C.
2
Bias Current specifications are guaranteed maximum at either input after five minutes of operation at TA = 25°C. For higher temperature, the current doubles every 10°C.
3
Defined as voltages between inputs, such that neither exceeds ±10 V from ground.
4
Not recommended for new designs; obsolete April 2002.
Specifications subject to change without notice.
4
4
AD548
REV. D
–3–
AD548
WARNING!
ESD SENSITIVE DEVICE
ABSOLUTE MAXIMUM RATINGS
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±18 V
Internal Power Dissipation
Input Voltage
3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V
2
. . . . . . . . . . . . . . . . . . . . 500 mW
l
Output Short Circuit Duration . . . . . . . . . . . . . . . . .Indefinite
Differential Input Voltage . . . . . . . . . . . . . . . . . . +V
and –V
S
Storage Temperature Range (Q, H) . . . . . . . –65°C to +150°C
(N, R) . . . . . . . . –65°C to +125°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 sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
2
Thermal Characteristics: 8-Pin SOIC Package: θJA = 160°C/W, θ
S
8-Lead Plastic Package: θJA = 90°C/W.
3
For supply voltages less than ± 18 V, the absolute maximum input voltage is equal
to the supply voltage.
Operating Temperature Range
AD548J/K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
AD548B . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
Lead Temperature Range (Soldering 60 sec) . . . . . . . . . 300°C
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 AD548 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.
= 42°C/W;
JC
–4–
REV. D
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