LT1457
Dual, Precision
JFET Input Op Amp
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DESCRIPTION
FEATURES
■
■
■
■
■
■
■
■
Handles 10,000pF Capacitive Load
450µV Max Offset Voltage
1200µV Max Offset Voltage in S8 Package
50pA Bias Current at 70°C
13nV/√Hz Voltage Noise
4V/µs Slew Rate
4µV/°C Drift
130dB Channel Separation
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APPLICATIONS
■
■
■
Sample-and-Hold (Drives Large Hold Capacitors)
A/D and D/A Converters
Photodiode Amplifiers
Voltage-to-Frequency Converters
Precision specifications include 220µV offset voltage in
plastic and surface mount packages. At 70°C input bias
current is 50pA, input offset current is 20pA. Channel
separation is 130dB.
Other dual JFET input op amps from Linear Technology
include the LT1057, which is three times faster than the
LT1457 but at the expense of significantly lower capacitive
load handling capability; and the LT1113 with 4.5nV/√Hz
voltage noise.
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The LT1457 is a dual, JFET input op amp optimized for
handling large capacitive loads in combination with precision performance.
TYPICAL PERFORMANCE CHARACTERISTICS
Capacitive Load Handling
Input Offset Voltage Distribution
S8 Package
21
100
18
PERCENT OF UNITS
OVERSHOOT (%)
80
VS = ±15V
TA = 25°C
AV = +1
60
40
15
VS = ±15V
TA = 25°C
400 DUALS
(800 OP AMPS)
TESTED FROM
3 RUNS
12
9
6
20
3
0
0.1
1
10
CAPACITIVE LOAD (nF)
100
LT11457• TA01
0
–1.0 –0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8 1.0
INPUT OFFSET VOLTAGE (mV)
LT1457 • TA02
1
LT1457
W
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W W
W
Supply Voltage ...................................................... ±20V
Differential Input Voltage ....................................... ±40V
Input Voltage .......................... Equal to Supply Voltages
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range ................ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
+
OUT A
1
8
V
–IN A
2
7
OUT B
+IN A
3
6
–IN B
V–
4
5
+IN B
LT1457ACN8
LT1457CN8
A
B
N8 PACKAGE
8-LEAD PLASTIC DIP
TJMAX = 115°C, θJA = 130°C/ W
TOP VIEW
+IN A
1
V–
2
+IN B
3
–IN B
A
B
4
8
–IN A
7
OUT A
6
V+
5
OUT B
LT1457S8
S8 PART MARKING
S8 PACKAGE
8-LEAD PLASTIC SOIC
1457
NOTE: THIS PIN CONFIGURATION DIFFERS FROM
THE 8-LEAD DIP PIN LOCATIONS. INSTEAD, IT
FOLLOWS THE INDUSTRY STANDARD LT1013DS8
SO PACKAGE CONFIGURATION.
TJMAX = 130°C, θJA = 190°C/ W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
VS = ±15V, TA = 25°C,VCM = 0V unless otherwise noted. (Note 1)
SYMBOL PARAMETER
VOS
Input Offset Voltage
CONDITIONS
LT1457AC/C
LT1457S8
IOS
Input Offset Current
Fully Warmed Up
IB
Input Bias Current
Input Resistance-Differential
-Common-Mode
MIN
LT1457AC
TYP
MAX
150
450
LT1457C/LT1457S8
MIN
TYP
MAX
200
800
220
1200
UNITS
µV
µV
3
40
Fully Warmed Up
±5
±50
VCM = –11V to 8V
VCM = 8V to 11V
1012
1012
1011
1012
1012
1011
Ω
Ω
Ω
4
4
pF
Input Capacitance
4
50
pA
±7
±75
pA
en
Input Noise Voltage
0.1Hz to 10Hz
2.0
2.1
µVP–P
en
Input Noise Voltage Density
fO = 10Hz
fO = 1kHz (Note 2)
26
13
22
28
14
24
nV/√Hz
nV/√Hz
1.5
4
1.8
6
fA/√Hz
in
Input Noise Current Density
fO = 10Hz, 1kHz (Note 3)
AVOL
Large-Signal Voltage Gain
VO = ±10V, RL = 2k
VO = ±10V, RL = 1k
Input Voltage Range
150
120
350
250
100
80
300
220
±10.5
14.3
–11.5
±10.5
14.3
–11.5
V/mV
V/mV
V
V
CMRR
Common-Mode Rejection Ratio
VCM = ±10.5V
86
100
82
98
dB
PSRR
Power Supply Rejection Ratio
VS = ±4.5V to ±18V
88
103
86
102
dB
VOUT
Output Voltage Swing
RL = 2k
±12
±13
±12
±13
SR
Slew Rate
2
4
2
4
2
V
V/µs
LT1457
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
CONDITIONS
GBW
Gain-Bandwidth Product
(Note 5)
IS
Supply Current Per Amplifier
Channel Separation
IOS
IB
AVOL
CMRR
PSRR
VOUT
IS
Average Temperature Coefficient of
Input Offset Voltage (Note 4)
Input Offset Current
Input Bias Current
Large-Signal Voltage Gain
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Output Voltage Swing
Supply Current Per Amplifier
MIN
1.0
DC to 5kHz, VIN = ±10V
IOS
IB
AVOL
CMRR
PSRR
VOUT
IS
1.0
3.0
1.7
1.8
UNITS
MHz
3.0
130
mA
dB
VS = ±15V, VCM = 0V, 0°C ≤ TA ≤ 70°C, unless otherwise noted.
CONDITIONS
LT1457AC/C
LT1457S8
MIN
●
●
●
Warmed Up, TA = 70°C
Warmed Up, TA = 70°C
VO = ±10V, RL = 2k
VCM = ±10.4V
VS = ±4.5V to ±18V
RL = 2k
●
●
●
●
70
85
87
±12
LT1457AC
TYP
MAX
250
900
3
10
18
±50
220
98
102
±12.8
150
±250
LT1457C/LT1457S8
MIN
TYP
MAX
330
1500
400
1900
4
16
50
80
84
±12
20
±60
200
96
100
±12.8
3.2
●
ELECTRICAL CHARACTERISTICS
Average Temperature Coefficient of
Input Offset Voltage
Input Offset Current
Input Bias Current
Large-Signal Voltage Gain
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Output Voltage Swing
Supply Current Per Amplifier
1.7
LT1457C/LT1457S8
MIN
TYP
MAX
132
TA = 70°C
SYMBOL PARAMETER
Input Offset Voltage
VOS
LT1457AC
TYP
MAX
1.8
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Input Offset Voltage
VOS
VS = ±15V, TA = 25°C,VCM = 0V unless otherwise noted. (Note 1)
250
±350
3.2
1.7
1.7
UNITS
µV
µV
µV/°C
pA
pA
V/mV
dB
dB
V
mA
mA
VS = ±15V, VCM = 0V, –40°C ≤ TA ≤ 85°C, unless otherwise noted. (Note 6)
CONDITIONS
LT1457AC/C
LT1457S8
MIN
●
●
●
Warmed Up, TA = 85°C
Warmed Up, TA = 85°C
VO = ±10V, RL = 2k
VCM = ±10.4V
VS = ±5V to ±17V
RL = 2k
TA = – 40°C
TA = 85°C
The ● denotes the specifications which apply over the full operating
temperature range.
Note 1: Typical parameters are defined as the 60% yield of distributions of
individual amplifiers; i.e., out of 100 LT1457s (200 op amps) typically 120
will be better than the indicated specification.
Note 2: This parameter is tested on a sample basis only.
Note 3: Current noise is calculated from the formula: in = (2qIb)1/2, where
q = 1.6 x 10 –19 coulomb. The noise of source resistors up to 1GΩ
swamps the contribution of current noise.
●
●
●
●
40
84
86
±12
LT1457AC
TYP
MAX
350
1100
3
10
0.1
± 0.2
120
97
100
±12.7
0.5
± 0.7
LT1457C/LT1457S8
MIN
TYP
MAX
400
1800
500
2300
4
16
30
80
83
±12
0.1
±0.2
110
95
98
±12.6
3.8
1.7
0.6
±0.9
3.8
1.7
UNITS
µV
µV
µV/°C
nA
nA
V/mV
dB
dB
V
mA
mA
Note 4: This parameter is not 100% tested.
Note 5: Gain-Bandwidth product is not tested. It is guaranteed by design
and by inference from the slew rate measurement.
Note 6: The LT1457 is not tested and not quality-assurance-sampled at
– 40°C and at 85°C. These specifications are guaranteed by design,
correlation, and/or inference from 0°C, 25°C, and 70°C tests.
3
LT1457
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TYPICAL PERFORMANCE CHARACTERISTICS
Input Bias and Offset Current vs
Temperature
Input Bias Current Over
the Common-Mode Range
100
BIAS CURRENT
30
10
OFFSET CURRENT
0
25
50
75
AMBIENT TEMPERATURE (°C)
120
100
TA = 70°C
80
60
40
20
0
–20
–15
100
18
15
12
9
6
0
5
Long Term Drift of
Representative Units
50
RL = 2k
VS = ±15V
VO = ±10V
VS = ±15V
TA = 25°C
40
300
RL = 1k
100
30
30
20
10
0
–10
–20
–30
–40
10
–50
0
0.2 0.4 0.6 0.8
–0.8 –0.6 –0.4 –0.2 0
INPUT OFFSET VOLTAGE (mV)
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
0
1
2
3
TIME (MONTHS)
4
LT1457 • TPC05
LT1457 • TPC04
Voltage Noise vs Frequency
5
LT1457 • TPC06
0.1Hz to 10Hz Noise
Channel Separation vs Frequency
100
160
VS = ±15V
TA = 25°C
CHANNEL SEPARATION (dB)
VS = ±15V
TA = 25°C
NOISE VOLTAGE (1µV/DIV)
70
50
30
20
140
LIMITED BY
THERMAL
INTERACTION AT
DC = 132dB
120
10
RS = 10Ω
LIMITED BY PIN TO
PIN CAPACITANCE
100
VS = ±15V
TA = 25°C
VIN = 20VP-P TO 5kHz
RL = 2k
80
1/f CORNER = 28Hz
RS = 1k
60
3
10
30
100 300 1k
FREQUENCY (Hz)
3k
10k
LT1457 • TPC07
4
1
2
3
4
TIME AFTER POWER ON (MINUTES)
LT1457 • TPC03
3
RMS VOLTAGE NOISE DENSITY (nV/√Hz)
N8 PACKAGE
30
15
1000
VOLTAGE GAIN (V/mV)
21
60
Voltage Gain vs Temperature
900 DUALS
(1800 OP AMPS)
TESTED FROM 3
RUNS
S8 PACKAGE
90
LT1457 • TPC02
Input Offset Voltage Distribution
N8 Package
VS = ±15V
TA = 25°C
120
0
–10
–5
0
5
10
COMMON-MODE INPUT VOLTAGE (V)
LT1457 • TPC01
24
VS = ±15V
TA = 25°C
TA = 25°C
OFFSET VOLTAGE CHANGE (µV)
300
VS = ±15V
140
CHANGE IN OFFSET VOLTAGE (µV)
VS = ±15V
VCM = 0V
WARMED UP
3
PERCENT OF UNITS
Warm-Up Drift
150
160
INPUT BIAS CURRENT (pA)
INPUT BIAS AND OFFSET CURRENT (pA)
1000
0
2
4
6
TIME (SECONDS)
8
10
LT1457 • TPC08
1
10
100
1k
10k
FREQUENCY (Hz)
100k
1M
LT1457 • TPC09
LT1457
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TYPICAL PERFORMANCE CHARACTERISTICS
Common-Mode Rejection Ratio
vs Frequency
Common-Mode Range vs
Temperature
15
120
VS = ±15V
TA = 25°C
VS = ±5V TO ±17V FOR PSRR
VS = ±15V, VCM = ±10.5V FOR CMRR
60
40
20
13
12
CMRR, PSRR (dB)
80
11
±10
–11
–12
–14
0
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
–25
0
25
50
TEMPERATURE (°C)
LT1457• TPC10
90
–50
100
8
2.0
1.5
GBW (MHz)
GBW
4
1.0
SLEW RISE
2
–25
0
25
50
TEMPERATURE (°C)
75
SUPPLY CURRENT PER AMPLIFIER (mA)
2.5
SLEW FALL
2
VS = ±15V
VS = ±5V
1
0
25
50
TEMPERATURE (°C)
80
60
CL = 1000pF
GAIN
0
–15
0.1
40
20
0
–5
–10
VS = ±15V
TA = 25°C
CL = 1000pF
–20
CL = 10pF
1.0
FREQUENCY (MHz)
75
100
10
LT1457 • TPC16
TA = 25°C
TA = 85°C
TA = 25°C
TA = 85°C
0
–10
–20
–30
TA = – 40°C
VS = ±15V
0
1
2
3
TIME FROM OUTPUT SHORT TO GROUND (MINUTES)
LT1457 • TPC15
Power Supply Rejection Ratio
vs Frequency
140
VS = ±15V
TA = 25°C
TA = 25°C
120
24
100
18
PSRR (dB)
100
PHASE
5
10
– 50
–25
30
CL = 10pF
10
20
Undistorted Output Swing vs
Frequency
PHASE MARGIN (DEG)
15
TA = – 40°C
LT1457 • TPC14
PEAK TO PEAK OUTPUT SWING (V)
20
100
30
– 40
Gain, Phase vs Frequency
75
Short-Circuit Current vs Time
(One Output Shorted to Ground)
40
0
–50
100
PHASE MARGIN = 80°, CL = 10pF
PHASE MARGIN = 51°, CL = 1000pF
0
25
50
TEMPERATURE (°C)
50
LT1457 • TPC18
25
–25
LT1457 • TPC12
3
VS = ±15V
SLEW RATE (V/µs)
75
Supply Current vs Temperature
10
–50
CMRR
100
LT1457 • TPC11
Slew Rate, Gain-Bandwidth
Product vs Temperature
6
PSRR
VS = ±15V
–15
– 50
10M
110
–13
SHORT-CIRCUIT CURRENT (mA)
CMRR (dB)
120
14
COMMON -MODE RANGE (V)
100
VOLTAGE GAIN (dB)
Common-Mode and Power Supply
Rejections vs Temperature
12
POSITIVE
SUPPLY
80
60
NEGATIVE
SUPPLY
40
6
20
0
10k
0
100k
1M
FREQUENCY (Hz)
10M
LT11457• TPC17
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
10M
LT1457• TPC13
5
LT1457
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TYPICAL PERFORMANCE CHARACTERISTICS
Large-Signal Response
AV = 1, CL = 100pF
Small-Signal Response
AV = 1, CL = 1000pF
LT1457 TPC19
Small-Signal Response
AV = 1, CL = 10,000pF
LT1457 TPC20
LT1457 TPC21
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APPLICATIONS INFORMATION
Phase Reversal Protection
Most industry standard JFET input single, dual, and quad
op amps (e.g., LF156, LF351, LF353, LF411, LF412,
OP-15, OP-16, OP-215, and TL084) exhibit phase reversal
at the output when the negative common-mode limit at the
input is exceeded (i.e., below –12V with ±15V supplies).
The photos show a ±16V sine wave input (A), the response
of an LF412A in the unity gain follower mode (B), and the
response of the LT1457 (C).
The phase reversal of photo (B) can cause lock-up in servo
systems. The LT1457 does not phase-reverse due to a
unique phase reversal protection circuit.
LT1457 AI01
(A) ±16V Sine Wave Input
LT1457 AI02
(B) LF412A Output
All Photos 5V/Div Vertical Scale, 50µs/Div Horizontal Scale
6
LT1457 AI03
(C) LT1457 Output
LT1457
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APPLICATIONS INFORMATION
High Speed Operation
When the feedback around the op amp is resisitive (RF), a
pole will be created with RF, the source resistance and
capacitance (RS, CS), and the amplifier input capacitance
(CIN ≈ 4pF). In low closed loop gain configurations and
with RS and RF in the kilohm range, this pole can create
excess phase shift and even oscillation on high speed
amplifiers. Because the LT1457’s phase margin is very
high, this problem is minimal. However, a small capacitor
(CF) in parallel with RF eliminates this problem. With RS(CS
+ CIN) = RFCF, the effect of the feedback pole is completely
removed.
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PACKAGE DESCRIPTION
CF
RF
–
CIN
CS
RS
OUTPUT
+
LT1457 AI04
Dimension in inches (millimeters) unless otherwise noted.
N8 Package
8-Lead Plastic DIP
0.300 – 0.320
(7.620 – 8.128)
0.045 – 0.065
(1.143 – 1.651)
0.130 ± 0.005
(3.302 ± 0.127)
0.400
(10.160)
MAX
8
0.009 – 0.015
(0.229 – 0.381)
(
+0.025
0.325 –0.015
8.255
+0.635
–0.381
7
0.045 ± 0.015
(1.143 ± 0.381)
)
0.100 ± 0.010
(2.540 ± 0.254)
0.125
(3.175)
MIN
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.250 ± 0.010
(6.350 ± 0.254)
1
0.018 ± 0.003
(0.457 ± 0.076)
2
4
3
N8 0392
0.189 – 0.197
(4.801 – 5.004)
8
0.053 – 0.069
(1.346 – 1.752)
7
6
5
0.004 – 0.010
(0.101 – 0.254)
0.008 – 0.010
(0.203 – 0.254)
0°– 8° TYP
5
0.020
(0.508)
MIN
S8 Package
8-Lead Plastic SOIC
0.016 – 0.050
0.406 – 1.270
6
0.065
(1.651)
TYP
0.014 – 0.019
(0.355 – 0.483)
0.050
(1.270)
BSC
0.228 – 0.244
(5.791 – 6.197)
0.150 – 0.157
(3.810 – 3.988)
1
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
2
3
4
SO8 0392
7
LT1457
U.S. Area Sales Offices
NORTHEAST REGION
Linear Technology Corporation
One Oxford Valley
2300 E. Lincoln Hwy.,Suite 306
Langhorne, PA 19047
Phone: (215) 757-8578
FAX: (215) 757-5631
SOUTHEAST REGION
Linear Technology Corporation
17060 Dallas Parkway
Suite 208
Dallas, TX 75248
Phone: (214) 733-3071
FAX: (214) 380-5138
SOUTHWEST REGION
Linear Technology Corporation
22141 Ventura Blvd.
Suite 206
Woodland Hills, CA 91364
Phone: (818) 703-0835
FAX: (818) 703-0517
Linear Technology Corporation
266 Lowell St., Suite B-8
Wilmington, MA 01887
Phone: (508) 658-3881
FAX: (508) 658-2701
CENTRAL REGION
Linear Technology Corporation
Chesapeake Square
229 Mitchell Court, Suite A-25
Addison, IL 60101
Phone: (708) 620-6910
FAX: (708) 620-6977
NORTHWEST REGION
Linear Technology Corporation
782 Sycamore Dr.
Milpitas, CA 95035
Phone: (408) 428-2050
FAX: (408) 432-6331
International Sales Offices
FRANCE
Linear Technology S.A.R.L.
Immeuble "Le Quartz"
58 Chemin de la Justice
92290 Chatenay Malabry
France
Phone: 33-1-41079555
FAX: 33-1-46314613
KOREA
Linear Technology Korea Branch
Namsong Building, #505
Itaewon-Dong 260-199
Yongsan-Ku, Seoul
Korea
Phone: 82-2-792-1617
FAX: 82-2-792-1619
TAIWAN
Linear Technology Corporation
Rm. 801, No. 46, Sec. 2
Chung Shan N. Rd.
Taipei, Taiwan, R.O.C.
Phone: 886-2-521-7575
FAX: 886-2-562-2285
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Linear Techonolgy GmbH
Untere Hauptstr. 9
D-85386 Eching
Germany
Phone: 49-89-3197410
FAX: 49-89-3194821
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Linear Technology Pte. Ltd.
101 Boon Keng Road
#02-15 Kallang Ind. Estates
Singapore 1233
Phone: 65-293-5322
FAX: 65-292-0398
UNITED KINGDOM
Linear Technology (UK) Ltd.
The Coliseum, Riverside Way
Camberley, Surrey GU15 3YL
United Kingdom
Phone: 44-276-677676
FAX: 44-276-64851
JAPAN
Linear Technology KK
5F YZ Bldg.
4-4-12 Iidabashi, Chiyoda-Ku
Tokyo, 102 Japan
Phone: 81-3-3237-7891
FAX: 81-3-3237-8010
World Headquarters
Linear Technology Corporation
1630 McCarthy Blvd.
Milpitas, CA 95035-7487
Phone: (408) 432-1900
FAX: (408) 434-0507
0294
8
Linear Technology Corporation
LT/GP 0594 10K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977
 LINEAR TECHNOLOGY CORPORATION 1994