1
LT1055/LT1056
Precision, High Speed,
JFET Input Operational Amplifiers
+
0V TO 10V
INPUT
10kHZ
TRIM
5k
4.7k
15V
2N3906
15V
15V
LT1055/56 TA01
15V
= 1N4148
3M
0.001 (POLYSTYRENE)
0.1F
THE LOW OFFSET VOLTAGE OF LT1056
CONTRIBUTES ONLY 0.1Hz OF ERROR
WHILE ITS HIGH SLEW RATE PERMITS
10kHz OPERATION.
0.1F
22k
1.5k
LM329
3.3M
7
6
4
3
2
33pF
*1% FILM
OUTPUT
1Hz TO 10kHz
0.005%
LINEARITY
LT1056
DESCRIPTIO
N
U
FEATURES
s
Guaranteed Offset Voltage
150
V Max
55
C to 125
C
500
V Max
s
Guaranteed Drift
4
V/
C Max
s
Guaranteed Bias Current
70
C
150pA Max
125
C
2.5nA Max
s
Guaranteed Slew Rate
12V/
s Min
APPLICATIO
N
S
U
s
Precision, High Speed Instrumentation
s
Logarithmic Amplifiers
s
D/A Output Amplifiers
s
Photodiode Amplifiers
s
Voltage-to-Frequency Converters
s
Frequency-to-Voltage Converters
s
Fast, Precision Sample-and-Hold
The LT1055/LT1056 JFET input operational amplifiers
combine precision specifications with high speed perfor-
mance.
For the first time, 16V/
s slew rate and 6.5MHz gain-ban-
width product are simultaneously achieved with offset
voltage of typically 50
V, 1.2
V/
C drift, bias currents of
40pA at 70
C and 500pA at 125
C.
The 150
V maximum offset voltage specification is the
best available on any JFET input operational amplifier.
The LT1055 and LT1056 are differentiated by their operat-
ing currents. The lower power dissipation LT1055 achieves
lower bias and offset currents and offset voltage. The
additional power dissipation of the LT1056 permits higher
slew rate, bandwidth and faster settling time with a slight
sacrifice in DC performance.
The voltage-to-frequency converter shown below is one of
the many applications which utilize both the precision and
high speed of the LT1055/LT1056.
For a JFET input op amp with 23V/
s guaranteed slew rate,
refer to the LT1022 data sheet.
and LTC are registered trademarks and LT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
N
U
Distribution of Input Offset Voltage
(H Package)
0kHz to 10kHz Voltage-to-Frequency Converter
INPUT OFFSET VOLTAGE (
V)
0
NUMBER OF UNITS
20
60
80
100
140
400
0
200
LT1055/56 TA02
40
120
400
200
V
S
=
15V
T
A
= 25
C
634 UNITS TESTED
FROM THREE RUNS
50% TO
60
V
2
LT1055/LT1056
Supply Voltage ......................................................
20V
Differential Input Voltage .......................................
40V
Input Voltage .........................................................
20V
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range
LT1055AM/LT1055M/LT1056AM/
LT1056M ......................................... 55
C to 125
C
LT1055AC/LT1055C/LT1056AC/
LT1056C ................................................ 0
C to 70
C
Storage Temperature Range
All Devices ...................................... 65
C to 150
C
Lead Temperature (Soldering, 10 sec).................. 300
C
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
ORDER PART
NUMBER
LT1055CN8
LT1056CN8
LT1055M/LT1056M
LT1055CH/LT1056CH
LT1055CN8/LT1056CN8
LT1055AM/LT1056AM
LT1055AC/LT1056AC
V
S
=
15V, T
A
= 25
C, V
CM
= 0V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Consult factory for Industrial grade parts.
1
2
3
4
8
7
6
5
TOP VIEW
BAL
IN
+
IN
V
N/C
V
+
OUT
BAL
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 100
C,
JA
= 130
C/ W
LT1056ACH
LT1056CH
LT1056AMH
LT1056MH
LT1055ACH
LT1055CH
LT1055AMH
LT1055MH
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage (Note1)
LT1055 H Package
--
50
150
--
70
400
V
LT1056 H Package
--
50
180
--
70
450
V
LT1055 N8 Package
--
--
--
--
120
700
V
LT1056 N8 Package
--
--
--
--
140
800
V
I
OS
Input Offset Current
Fully Warmed Up
--
2
10
--
2
20
pA
I
B
Input Bias Current
Fully Warmed Up
--
10
50
--
10
50
pA
V
CM
= 10V
--
30
130
--
30
150
pA
Input Resistance:Differential
--
10
12
--
--
10
12
--
Common Mode
V
CM
= 11V to 8V
--
10
12
--
--
10
12
--
V
CM
= 8V to 11V
--
10
11
--
--
10
11
--
Input Capacitance
--
4
--
--
4
--
pF
e
n
Input Noise Voltage
0.1Hz to 10Hz
LT1055
--
1.8
--
--
2.0
--
V
P-P
LT1056
--
2.5
--
--
2.8
--
V
P-P
Input Noise Voltage Density
f
0
= 10Hz (Note 2)
--
28
50
--
30
60
nV/
Hz
f
0
= 1kHz (Note 3)
--
14
20
--
15
22
nV/
Hz
I
n
Input Noise Current Density
f
0
= 10Hz, 1kHz (Note 4)
--
1.8
4
--
1.8
4
fA/
Hz
A
VOL
Large-Signal Voltage Gain
V
0
=
10V
R
L
= 2k
150
400
--
120
400
--
V/mV
R
L
= 1k
130
300
--
100
300
--
V/mV
Input Voltage Range
11
12
--
11
12
--
V
CMRR
Common-Mode Rejection Ratio
V
CM
=
11V
86
100
--
83
98
--
dB
PSRR
Power Supply Rejection Ratio
V
S
=
10V to
18V
90
106
--
88
104
--
dB
V
OUT
Output Voltage Swing
R
L
= 2k
12
13.2
--
12
13.2
--
V
SR
Slew Rate
LT1055
10
13
--
7.5
12
--
V/
s
LT1056
12
16
--
9.0
14
--
V/
s
GBW
Gain-Bandwidth Product
f = 1MHz
LT1055
--
5.0
--
--
4.5
--
MHz
LT1056
--
6.5
--
--
5.5
--
MHz
I
S
Supply Current
LT1055
--
2.8
4.0
--
2.8
4.0
mA
LT1056
--
5.0
6.5
--
5.0
7.0
mA
Offset Voltage Adjustment Range
R
POT
= 100k
--
5
--
--
5
--
mV
TOP VIEW
NC
BALANCE
OUT
BALANCE
+
IN
V
8
7
6
5
3
2
1
4
H PACKAGE
8-LEAD TO-5 METAL CAN
IN
V
+
T
JMAX
= 150
C,
JA
= 150
C/ W,
JC
= 45
C/ W
3
LT1055/LT1056
LT1055AM
LT1055M
LT1056AM
LT1056M
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage (Note1)
LT1055
q
--
180
500
--
250
1200
V
LT1056
q
--
180
550
--
250
1250
V
Average Temperature
(Note 5)
q
--
1.3
4.0
--
1.8
8.0
V/
C
Coefficient of Input Offset
Voltage
I
OS
Input Offset Current
Warmed Up
LT1055
q
--
0.20
1.2
--
0.25
1.8
nA
T
A
= 125
C
LT1056
q
--
0.25
1.5
--
0.30
2.4
nA
I
B
Input Bias Current
Warmed Up
LT1055
q
--
0.4
2.5
--
0.5
4.0
nA
T
A
= 125
C
LT1056
q
--
0.5
3.0
--
0.6
5.0
nA
A
VOL
Large-Signal Voltage Gain
V
O
=
10V, R
L
= 2k
q
40
120
--
35
120
--
V/mV
CMRR
Common-Mode Rejection Ratio
V
CM
=
10.5V
q
85
100
--
82
98
--
dB
PSRR
Power Supply Rejection Ratio
V
S
=
10V to
17V
q
88
104
--
86
102
--
dB
V
OUT
Output Voltage Swing
R
L
= 2k
q
12
12.9
--
12
12.9
--
V
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage (Note1)
LT1055 H Package
q
--
100
330
--
140
750
V
LT1056 H Package
q
--
100
360
--
140
800
V
LT1055 N8 Package
q
--
--
--
--
250
1250
V
LT1056 N8 Package
q
--
--
--
--
280
1350
V
Average Temperature
H Package (Note 5)
q
--
1.2
4.0
--
1.6
8.0
V/
C
Coefficient of Input Offset
N8 Package (Note 5)
q
--
--
--
--
3.0
12.0
V/
C
Voltage
I
OS
Input Offset Current
Warmed Up
LT1055
q
--
10
50
--
16
80
pA
T
A
= 70
C
LT1056
q
--
14
70
--
18
100
pA
I
B
Input Bias Current
Warmed Up
LT1055
q
--
30
150
--
40
200
pA
T
A
= 70
C
LT1056
q
--
40
80
--
50
240
pA
A
VOL
Large-Signal Voltage Gain
V
O
=
10V, R
L
= 2k
q
80
250
--
60
250
--
V/mV
CMRR
Common-Mode Rejection Ratio
V
Cm
=
10.5V
q
85
100
--
82
98
--
dB
PSRR
Power Supply Rejection Ratio
V
S
=
10V to
18V
q
89
105
--
87
103
--
dB
V
OUT
Output Voltage Swing
R
L
= 2k
q
12
13.1
--
12
13.1
--
V
LT1055AC
LT1056AC
V
S
=
15V, V
CM
= 0V, 55
C
T
A
125
C unless otherwise noted.
The
q
denotes specifications which apply over the full operating
temperature range.
For MIL-STD components, please refer to LTC883 data sheet for test
listing and parameters.
Note 1: Offset voltage is measured under two different conditions:
(a) approximately 0.5 seconds after application of power; (b) at T
A
= 25
C
only, with the chip heated to approximately 38
C for the LT1055 and to
45
C for the LT1056, to account for chip temperature rise when the device
is fully warmed up.
Note 2: 10Hz noise voltage density is sample tested on every lot of A
grades. Devices 100% tested at 10Hz are available on request.
Note 3: This parameter is tested on a sample basis only.
Note 4: Current noise is calculated from the formula: i
n
= (2ql
B
)
1/2
, where
q = 1.6
10
19
coulomb. The noise of source resistors up to 1G
swamps the contribution of current noise.
Note 5: Offset voltage drift with temperature is practically unchanged when
the offset voltage is trimmed to zero with a 100k potentiometer between
the balance terminals and the wiper tied to V
+
. Devices tested to tighter
drift specifications are available on request.
LT1055CH/LT1056CH
LT1055CN8/LT1056CN8
V
S
=
15V, V
CM
= 0V, 0
C
T
A
70
C unless otherwise noted.
4
LT1055/LT1056
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
0.1Hz to 10Hz Noise
LT1055/56 G02
COMMON-MODE INPUT VOLTAGE (V)
15
120
INPUT BIAS CURRENT, T
A
= 25C, T
A
= 70C (pA)
80
40
0
40
120
10
5
0
5
10
15
80
1200
800
400
0
400
1200
800
V
S
= 15V
WARMED UP
T
A
= 125C
T
A
= 125C
T
A
= 25C
T
A
= 70C
T
A
= 70C
A = POSITIVE INPUT CURRENT
B = NEGATIVE INPUT CURRENT
A
B
B
A
INPUT BIAS CURRENT, T
A
= 125C (pA)
Warm-Up Drift
Distribution of Offset Voltage Drift
with Temperature (H Package)*
Input Bias and Offset Currents
vs Temperature
AMBIENT TEMPERATURE (C)
0
INPUT BIAS AND OFFSET CURRENT (pA)
100
300
1000
100
LT1055/56 G01
30
10
3
25
50
75
125
BIAS OR OFFSET CURRENTS
MAY BE POSITIVE OR NEGATIVE
BIAS CURRENT
OFFSET CURRENT
V
S
= 15V
V
CM
= 0V
WARMED UP
Input Bias Current Over the
Common-Mode Range
Distribution of Input Offset
Voltage (N8 Package)
TIME AFTER POWER ON (MINUTES)
0
CHANGE IN OFFSET VOLTAGE (V)
60
80
100
4
LT1055/56 G05
40
20
0
1
2
3
5
V
S
= 15V
T
A
= 25C
LT1056CN8
LT1055CN8
LT1056 H PACKAGE
LT1055 H PACKAGE
Long Term Drift of
Representative Units
TIME (MONTHS)
0
OFFSET VOLTAGE CHANGE V)
50
50
40
40
30
30
20
20
10
10
0
4
LT1055/56 GO6
1
2
3
5
V
S
= 15V
T
A
= 25C
TIME (SECONDS)
0
NOISE VOLTAGE (1V/DIVISION)
8
LT1055/56 GO7
2
4
6
10
LT1056
LT1055
RMS NOISE VOLTAGE DENSITY (nV/
Hz)
FREQUENCY (Hz)
1
100
30
300
LT1055/56 G09
30
10
3
10
100
300
1000
1000
LT1056
1/f CORNER = 28HZ
LT1055
1/f CORNER
= 20HZ
V
S
= 15V
T
A
= 25C
Voltage Noise vs Frequency
Noise vs Chip Temperature
CHIP TEMPERATURE (C)
20
1
2
3
5
7
10
10
20
30
50
70
100
40
LT1055/56 G08
0.1Hz TO 10Hz PEAK-TO-PEAK NOISE (V/
P-P
)
10
80
30
50
60
70
f
0
= 10kHz
f
0
= 1kHz
PEAK-TO-PEAK
NOISE
RMS NOISE VOLTAGE DENSITY (nV/
Hz)
INPUT OFFSET VOLTAGE (
V)
800
NUMBER OF INPUTS
80
100
120
800
LT1055/56 G03
60
40
0
400
0
400
20
160
140
600
200
200
600
V
S
=
15V
T
A
= 25
C
550 UNITS
TESTED FROM
TWO RUNS
(LT1056)
50% YIELD
TO
140
V
OFFSET VOLTAGE DRIFT WITH TEMPERATURE (
V/
C)
10
0
BATTERY VOLTAGE (V)
20
60
80
100
140
8
0
4
LT1055/56 G04
40
120
2
8
10
6 4
2
6
*DISTRIBUTION IN THE PLASTIC (N8) PACKAGE
IS SIGNIFICANTLY WIDER.
V
S
=
15V
634 UNITS TESTED
FROM THREE RUNS
50% TO
1.5
V/
C
5
LT1055/LT1056
A
V
= 1, C
L
= 100pF, 0.5
s/DIV
5V/DIV
LT1056 Large-Signal Response
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
LT1055/56 G10
LT1055/56 G12
A
V
= 1, C
L
= 100pF, 0.5
s/DIV
5V/DIV
Undistorted Output Swing vs
Frequency
Output Impedence vs Frequency
FREQUENCY (kHz)
1
0.1
OUTPUT IMPEDANCE (
)
1
10
100
10
100
1000
LT1055/56 G15
V
S
= 15V
T
A
= 25C
A
V
= 100
LT1055
LT1056
LT1055
LT1056
LT1056
A
V
= 10
LT1055
A
V
= 1
Gain vs Frequency
FREQUENCY (Hz)
1
GAIN (dB)
60
80
100
100M
LT1055/56 G16
40
20
20
100
10k
1M
0
140
120
10
1k
100k
10M
V
S
= 15V
T
A
= 25C
LT1055
LT1056
TEMPERATURE (C)
25
10
100
30
1000
300
25
75
LT1055/56 G18
VOLTAGE GAIN (V/mV)
75
125
R
L
= 1k
R
L
= 2k
V
S
= 15V
V
O
= 10V
Voltage Gain vs Temperature
FREQUENCY (MHz)
0.1
0
PEAK-TO-PEAK OUTPUT SWING (V)
6
12
18
24
1
10
LT1055/56 G13
30
LT1055
LT1056
V
S
= 15V
T
A
= 25C
FREQUENCY (MHz)
1
GAIN (dB)
PHASE SHIFT (DEGREES)
10
10
LT1055/56 G17
0
10
2
4
20
100
120
140
160
6
8
V
S
= 15V
T
A
= 25C
PHASE
GAIN
LT1055
LT1056
LT1055
LT1056
Small-Signal Response
20mV/DIV
A
V
= 1, C
L
= 100pF, 0.2
s/DIV
LT1055/56 G11
Slew Rate, Gain-Bandwidth vs
Temperature
Gain, Phase Shift vs Frequency
TEMPERATURE (C)
SLEW RATE (V/S)
GAIN-BANDWIDTH PRODUCT (MHz)
20
30
25
75
LT1055/56 G14
10
25
125
0
10
8
6
4
2
V
S
= 15V
f
0
= 1MHz FOR GBW
LT1056 GBW
LT1055 GBW
LT1055 SLEW
LT1056 SLEW
LT1055 Large-Signal Response
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