Linear LT1028CS8, LT1128CS8 Schematic [ru]
FEATURES
■
Voltage Noise
1.1nV/√Hz Max at 1kHz
0.85nV/√Hz Typ at 1kHz
1.0nV/√Hz Typ at 10Hz
35nV
■
Voltage and Current Noise 100% Tested
■
Gain-Bandwidth Product
Typ, 0.1Hz to 10Hz
P-P
LT1028: 50MHz Min
LT1128: 13MHz Min
■
Slew Rate
LT1028: 11V/µs Min
LT1128: 5V/µs Min
■
Offset Voltage: 40µV Max
■
Drift with Temperature: 0.8µV/°C Max
■
Voltage Gain: 7 Million Min
■
Available in 8-Pin SO Package
U
APPLICATIO S
LT1028/LT1128
Ultralow Noise Precision
High Speed Op Amps
U
DESCRIPTIO
The LT®1028(gain of –1 stable)/LT1128(gain of +1 stable)
achieve a new standard of excellence in noise performance
with 0.85nV/√Hz 1kHz noise, 1.0nV/√Hz 10Hz noise. This
ultralow noise is combined with excellent high speed
specifications (gain-bandwidth product is 75MHz for
LT1028, 20MHz for LT1128), distortion-free output, and
true precision parameters (0.1µV/°C drift, 10µV offset
voltage, 30 million voltage gain). Although the LT1028/
LT1128 input stage operates at nearly 1mA of collector
current to achieve low voltage noise, input bias current is
only 25nA.
The LT1028/LT1128’s voltage noise is less than the noise
of a 50Ω resistor. Therefore, even in very low source
impedance transducer or audio amplifier applications, the
LT1028/LT1128’s contribution to total system noise will
be negligible.
, LTC and LT are registered trademarks of Linear Technology Corporation
■
Low Noise Frequency Synthesizers
■
High Quality Audio
■
Infrared Detectors
■
Accelerometer and Gyro Amplifiers
■
350Ω Bridge Signal Conditioning
■
Magnetic Search Coil Amplifiers
■
Hydrophone Amplfiers
TYPICAL APPLICATIO
Flux Gate Amplifier
SQUARE
WAVE
DRIVE
1kHz
FLUX GATE
TYPICAL
SCHONSTEDT
#203132
U
+
LT1028
–
DEMODULATOR
SYNC
OUTPUT TO
DEMODULATOR
1k
50Ω
1028/1128 TA01
VOLTAGE NOISE DENSITY (nV/√Hz)
Voltage Noise vs Frequency
10
MAXIMUM
1/f CORNER = 14Hz
TYPICAL
1
1/f CORNER = 3.5Hz
0.1
0.1
1
FREQUENCY (Hz)
10
VS = ±15V
= 25°C
T
A
100
1028/1128 TA02
1k
1
LT1028/LT1128
TOP VIEW
SW PACKAGE
16-LEAD PLASTIC SOL
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
NC
NC
TRIM
–IN
+IN
V
–
NC
NC
NC
NC
TRIM
V
+
OUT
NC
NC
NOTE: THIS DEVICE IS NOT RECOMMENDED FOR NEW DESIGNS
OVERCOMP
+
–
A
W
O
LUTEXI TIS
S
A
WUW
U
(Note 1)
ARB
G
Supply Voltage
–55°C to 105°C ................................................ ±22V
105°C to 125°C ................................................ ±16V
Differential Input Current (Note 9) ......................±25mA
Input Voltage ............................ Equal to Supply Voltage
Output Short Circuit Duration .......................... Indefinite
PACKAGE
1
TRIM
V
OS
2
–IN
3
+IN
H PACKAGE
8-LEAD TO-5 METAL CAN
T
= 175°C, θJA = 140°C/W, θJC = 40°C/W
JMAX
/
O
RDER I FOR ATIO
TOP VIEW
VOS TRIM
8
–
+
4
–
V
(CASE)
7
5
+
V
6
OUT
OVERCOMP
ORDER PART
LT1028AMH
LT1028MH
LT1028ACH
LT1028CH
WU
NUMBER
U
OBSOLETE PACKAGE
Consider S8 or N8 Packages for Alternate Source
Operating Temperature Range
LT1028/LT1128AM, M (OBSOLETE). –55°C to 125°C
LT1028/LT1128AC, C (Note 11) ......... – 40°C to 85°C
Storage Temperature Range
All Devices........................................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec.)................. 300°C
ORDER PART
NUMBER
TOP VIEW
V
OS
1
TRIM
–IN
+IN
–
V
T
–
2
+
3
45
S8 PACKAGE
8-LEAD PLASTIC SOIC
= 135°C, θJA = 140°C/W
JMAX
8
7
6
V
OS
TRIM
V+
OUT
OVER-
COMP
LT1028CS8
LT1128CS8
S8 PART MARKING
1028
1128
V
OS
TRIM
–IN
+IN
–
V
T
Consult LTC Marketing for parts specified with wider operating temperature ranges.
2
TOP VIEW
V
1
–
2
+
3
45
N8 PACKAGE
8-LEAD PLASTIC DIP
= 130°C, θJA = 130°C/W
JMAX
J8 PACKAGE
8-LEAD CERAMIC DIP
T
= 165°C, θJA = 100°C/W
JMAX
OS
8
TRIM
V+
7
6
OUT
OVER-
COMP
OBSOLETE PACKAGE
Consider N8 Package for Alternate Source
ORDER PART
NUMBER
LT1028ACN8
LT1028CN8
LT1128ACN8
LT1128CN8
LT1028AMJ8
LT1028MJ8
LT1028ACJ8
LT1028CJ8
LT1128AMJ8
LT1128MJ8
LT1128CJ8
T
= 140°C, θJA = 130°C/W
JMAX
ORDER PART
NUMBER
LT1028CSW
LECTRICAL C CHARA TERIST
E
ICS
VS = ±15V, TA = 25°C, unless otherwise noted.
LT1028/LT1128
LT1028AM/AC
LT1128AM/AC
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
V
OS
∆V
∆Time Voltage Stability
I
OS
I
B
e
n
I
n
CMRR Common Mode Rejection Ratio VCM = ±11V 114 126 110 126 dB
PSRR Power Supply Rejection Ratio VS = ±4V to ±18V 117 133 110 132 dB
A
VOL
V
OUT
SR Slew Rate A
GBW Gain-Bandwidth Product fO = 20kHz (Note 7) LT1028 50 75 50 75 MHz
Z
O
I
S
Input Offset Voltage (Note 2) 10 40 20 80 µV
Long Term Input Offset (Note 3) 0.3 0.3 µV/Mo
OS
Input Offset Current VCM = 0V 12 50 18 100 nA
Input Bias Current VCM = 0V ±25 ±90 ±30 ±180 nA
Input Noise Voltage 0.1Hz to 10Hz (Note 4) 35 75 35 90 nV
Input Noise Voltage Density fO = 10Hz (Note 5) 1.00 1.7 1.0 1.9 nV/√Hz
fO = 1000Hz, 100% tested 0.85 1.1 0.9 1.2 nV/√Hz
Input Noise Current Density fO = 10Hz (Note 4 and 6) 4.7 10.0 4.7 12.0 pA/√Hz
fO = 1000Hz, 100% tested 1.0 1.6 1.0 1.8 pA/√Hz
Input Resistance
Common Mode 300 300 MΩ
Differential Mode 20 20 kΩ
Input Capacitance 5 5 pF
Input Voltage Range ±11.0 ±12.2 ±11.0 ±12.2 V
Large-Signal Voltage Gain RL ≥ 2k, VO = ±12V 7.0 30.0 5.0 30.0 V/µV
R
≥ 1k, VO = ±10V 5.0 20.0 3.5 20.0 V/µV
L
RL ≥ 600Ω, VO = ±10V 3.0 15.0 2.0 15.0 V/µV
Maximum Output Voltage Swing RL ≥ 2k ±12.3 ±13.0 ±12.0 ±13.0 V
RL ≥ 600Ω±11.0 ±12.2 ±10.5 ±12.2 V
= –1 LT1028 11.0 15.0 11.0 15.0 V/µs
VCL
A
= –1 LT1128 5.0 6.0 4.5 6.0 V/µs
VCL
fO = 200kHz (Note 7) LT1128 13 20 11 20 MHz
Open-Loop Output Impedance VO = 0, IO = 0 80 80 Ω
Supply Current 7.4 9.5 7.6 10.5 mA
LT1028M/C
LT1128M/C
P-P
LECTRICAL C CHARA TERIST
E
ICS
The ● denotes the specifications which apply over the temperature range
–55°C ≤ TA ≤ 125°C. VS = ±15V, unless otherwise noted.
LT1028AM
LT1128AM
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
V
OS
∆V
∆Temp
I
OS
I
B
CMRR Common Mode Rejection Ratio VCM = ±10.3V ● 106 122 100 120 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±16V ● 110 130 104 130 dB
A
VOL
V
OUT
I
S
Input Offset Voltage (Note 2) ● 30 120 45 180 µV
Average Input Offset Drift (Note 8) ● 0.2 0.8 0.25 1.0 µV/°C
OS
Input Offset Current VCM = 0V ● 25 90 30 180 nA
Input Bias Current VCM = 0V ● ±40 ±150 ±50 ±300 nA
Input Voltage Range ● ±10.3 ±11.7 ±10.3 ±11.7 V
Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V ● 3.0 14.0 2.0 14.0 V/µV
RL ≥ 1k, VO = ±10V 2.0 10.0 1.5 10.0 V/µV
Maximum Output Voltage Swing RL ≥ 2k ● ±10.3 ±11.6 ±10.3 ±11.6 V
Supply Current ● 8.7 11.5 9.0 13.0 mA
LT1028M
LT1128M
3
LT1028/LT1128
LECTRICAL C CHARA TERIST
E
0°C ≤ TA ≤ 70°C. VS = ±15V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
V
OS
∆V
∆Temp
I
OS
I
B
CMRR Common Mode Rejection Ratio VCM = ±10.5V ● 110 124 106 124 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±18V ● 114 132 107 132 dB
A
VOL
V
OUT
I
S
E
–40°C ≤ TA ≤ 85°C. VS = ±15V, unless otherwise noted. (Note 11)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
V
OS
∆V
∆Temp
I
OS
I
B
CMRR Common Mode Rejection Ratio VCM = ±10.5V ● 108 123 102 123 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±18V ● 112 131 106 131 dB
A
VOL
V
OUT
I
S
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Input Offset Voltage measurements are performed by automatic
test equipment approximately 0.5 sec. after application of power. In
addition, at T
approximately 55°C to account for the chip temperature rise when the
device is fully warmed up.
Note 3: Long Term Input Offset Voltage Stability refers to the average
trend line of Offset Voltage vs. Time over extended periods after the first
30 days of operation. Excluding the initial hour of operation, changes in
V
OS
Note 4: This parameter is tested on a sample basis only.
Note 5: 10Hz noise voltage density is sample tested on every lot with the
exception of the S8 and S16 packages. Devices 100% tested at 10Hz are
available on request.
Note 6: Current noise is defined and measured with balanced source
resistors. The resultant voltage noise (after subtracting the resistor noise
Input Offset Voltage (Note 2) ● 15 80 30 125 µV
Average Input Offset Drift (Note 8) ● 0.1 0.8 0.2 1.0 µV/°C
OS
Input Offset Current VCM = 0V ● 15 65 22 130 nA
Input Bias Current VCM = 0V ● ±30 ±120 ±40 ±240 nA
Input Voltage Range ● ±10.5 ±12.0 ±10.5 ±12.0 V
Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V ● 5.0 25.0 3.0 25.0 V/µV
Maximum Output Voltage Swing RL ≥ 2k ● ±11.5 ±12.7 ±11.5 ±12.7 V
Supply Current ● 8.0 10.5 8.2 11.5 mA
LECTRICAL C CHARA TERIST
Input Offset Voltage ● 20 95 35 150 µV
Average Input Offset Drift (Note 8) ● 0.2 0.8 0.25 1.0 µV/°C
OS
Input Offset Current VCM = 0V ● 20 80 28 160 nA
Input Bias Current VCM = 0V ● ±35 ±140 ±45 ±280 nA
Input Voltage Range ● ±10.4 ±11.8 ±10.4 ±11.8 V
Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V ● 4.0 20.0 2.5 20.0 V/µV
Maximum Output Voltage Swing RL ≥ 2k ● ±11.0 ±12.5 ±11.0 ±12.5 V
Supply Current ● 8.5 11.0 8.7 12.5 mA
= 25°C, offset voltage is measured with the chip heated to
A
during the first 30 days are typically 2.5µV.
ICS
RL ≥ 1k, VO = ±10V 4.0 18.0 2.5 18.0 V/µV
RL ≥ 600Ω (Note 10) ±9.5 ±11.0 ±9.0 ±10.5 V
ICS
RL ≥ 1k, VO = ±10V 3.0 14.0 2.0 14.0 V/µV
The ● denotes the specifications which apply over the temperature range
LT1028AC
LT1128AC
LT1028C
LT1128C
The ● denotes the specifications which apply over the temperature range
LT1028AC
LT1128AC
on an RMS basis) is divided by the sum of the two source resistors to
obtain current noise. Maximum 10Hz current noise can be inferred from
100% testing at 1kHz.
Note 7: Gain-bandwidth product is not tested. It is guaranteed by design
and by inference from the slew rate measurement.
Note 8: This parameter is not 100% tested.
Note 9: The inputs are protected by back-to-back diodes. Current-limiting
resistors are not used in order to achieve low noise. If differential input
voltage exceeds ±1.8V, the input current should be limited to 25mA.
Note 10: This parameter guaranteed by design, fully warmed up at T
70°C. It includes chip temperature increase due to supply and load
currents.
Note 11: The LT1028/LT1128 are designed, characterized and expected to
meet these extended temperature limits, but are not tested at –40°C and
85°C. Guaranteed I grade parts are available. Consult factory.
LT1028C
LT1128C
=
A
4
LPER
TEMPERATURE (°C)
–50
0
RMS VOLTAGE DENSITY (nV/√Hz)
0.8
2.0
0
50
75
LT1028/1128 • TPC09
O.4
1.6
1.2
–25
25
100
125
VS = ±15V
AT 10Hz
AT 1kHz
F
O
10Hz Voltage Noise Distribution
180
160
140
120
100
80
60
NUMBER OF UNITS
40
20
0
0.6
158
148
70
57
28
8
7
4
232
22
1
1.6 2.0 2.2
0.8 1.2
1.0
VOLTAGE NOISE DENSITY (nV/√Hz)
1.4
R
ATYPICA
VS = ±15V
T
= 25°C
A
500 UNITS
MEASURED
FROM 4 RUNS
3
2
11
1.8
LT1020/1120 • TPC01
UW
E
C
1
CCHARA TERIST
Wideband Noise, DC to 20kHz
VERTICAL SCALE = 0.5µV/DIV
HORIZONTAL SCALE = 0.5ms/DIV
ICS
LT1028/LT1128
Wideband Voltage Noise
(0.1Hz to Frequency Indicated)
10
VS = ±15V
= 25°C
T
A
1
0.1
RMS VOLTAGE NOISE (µV)
0.01
100
BANDWIDTH (Hz)
100k 1M 10M
10k1k
LT1028/1128 • TPC03
Total Noise vs Matched Source
Resistance
100
R
S
–
R
S
+
10
AT 10Hz
TOTAL NOISE DENSITY (nV/√Hz)
1
0.1
1
3 1k 10k
MATCHED SOURCE RESISTANCE (Ω)
2 RS NOISE ONLY
10 30 100 300 3k
0.1Hz to 10Hz Voltage Noise
VS = ±15V
= 25°C
T
A
AT 1kHz
VS = ±15V
= 25°C
T
A
LT1028/1128 • TPC04
Total Noise vs Unmatched
Source Resistance Current Noise Spectrum
100
R
S
10
AT 10Hz
1
TOTAL NOISE DENSITY (nV/√Hz)
0.1
1
3 1k 10k
UNMATCHED SOURCE RESISTANCE (Ω)
2 RS NOISE ONLY
10 30 100 300 3k
0.01Hz to 1Hz Voltage Noise
VS = ±15V
= 25°C
T
A
AT 1kHz
VS = ±15V
= 25°C
T
A
LT1028/1128 • TPC05
100
MAXIMUM
10
1/f CORNER = 800Hz
TYPICAL
1
1/f CORNER = 250Hz
CURRENT NOISE DENSITY (pA/√Hz)
0.1
10
100 1k 10k
FREQUENCY (Hz)
Voltage Noise vs Temperature
LT1028/1128 • TPC06
10nV
10nV
2
08
4
TIME (SEC)
6
10
LT1028/1128 • TPC07
080
20
40
TIME (SEC)
60
100
LT1028/1128 • TPC08
5
LT1028/LT1128
COMMON MODE INPUT VOLTAGE (V)
–15
–80
INPUT BIAS CURRENT (nA)
–60
–20
0
20
–5
5
15
100
LT1028/1128 • TPC15
–40
–10 0
40
60
80
10
RCM =
20V
65nA
≈ 300MΩ
V
S
= ±15V
T
A
= 25°C
POSITIVE INPUT CURRENT
(UNDERCANCELLED) DEVICE
NEGATIVE INPUT CURRENT
(OVERCANCELLED) DEVICE
LPER
F
O
R
ATYPICA
UW
CCHARA TERIST
E
C
ICS
Distribution of Input Offset
Voltage
20
VS = ±15V
18
= 25°C
T
A
800 UNITS TESTED
16
FROM FOUR RUNS
14
12
10
UNITS (%)
8
6
4
2
0
–40
–30
24
20
16
12
8
–50
VS = ±15V
T
–20
OFFSET VOLTAGE (µV)
= 25°C
A
–10
METAL CAN (H) PACKAGE
Offset Voltage Drift with
Temperature of Representative Units
50
VS = ±15V
40
30
20
10
0
–10
–20
OFFSET VOLTAGE (µV)
–30
–40
–50
0
10
20
30
40
50
LT1028/1128 • TPC10
–50
–25
0
TEMPERATURE (°C)
50
25
75
LT1028/1128 • TPC11
100
125
Input Bias and Offset Currents
Over Temperature
60
VS = ±15V
= 0V
V
CM
50
40
30
20
BIAS CURRENT
Long-Term Stability of Five
Representative Units
10
VS = ±15V
8
= 25°C
T
A
t = 0 AFTER 1 DAY PRE-WARM UP
6
4
2
0
–2
–4
–6
OFFSET VOLTAGE CHANGE (µV)
–8
–10
1
0
TIME (MONTHS)
3
2
Bias Current Over the Common
Mode RangeWarm-Up Drift
4
LT1028/1128 • TPC12
5
4
CHANGE IN OFFSET VOLTAGE (µV)
0
0
Voltage Noise vs Supply Voltage
1.5
TA = 25°C
1.25
1.0
0.75
RMS VOLTAGE NOISE DENSITY (nV/√Hz)
0.5
0
6
DUAL-IN-LINE PACKAGE
PLASTIC (N) OR CERDIP (J)
1234
TIME AFTER POWER ON (MINUTES)
LT1028/1128 • TPC13
AT 10Hz
±5 ±10
SUPPLY VOLTAGE (V)
AT 1kHz
±15
LT1028/1128 • TPC16
±20
10
INPUT BIAS AND OFFSET CURRENTS (nA)
5
0
–50
–25 0
Supply Current vs Temperature
10
9
8
7
6
5
4
3
SUPPLY CURRENT (mA)
2
1
0
–50
–25
OFFSET CURRENT
50 100 125
25 75
TEMPERATURE (˚C)
VS = ±15V
VS = ±5V
50
25
0
TEMPERATURE (°C)
LT1028/1128 • TPC14
75
100
LT1028/1128 • TPC17
Output Short-Circuit Current
vs Time
50
40
30
20
SOURCING
10
0
–10
–20
–30
SINKING
SHORT-CIRCUIT CURRENT (mA)
–40
–50
125
0
TIME FROM OUTPUT SHORT TO GROUND (MINUTES)
25°C
25°C
2
VS = ±15V
3
LT1028/1128 • TPC18
–50°C
125°C
125°C
–50°C
1
LPER
FREQUENCY (Hz)
10k
5
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
20
25
30
100k 1M 10M
LT1028/1128 • TPC27
15
10
LT1128 LT1028
VS = ±15V
T
A
= 25°C
R
L
= 2k
LT1028/LT1128
UW
R
F
O
ATYPICA
CCHARA TERIST
E
C
ICS
Voltage Gain vs Frequency
160
140
120
100
80
60
40
VOLTAGE GAIN (dB)
20
0
–20
0.01
LT1128 LT1028
0.1 1 10 100 1k 10k 100k 1M 10M 100M
FREQUENCY (Hz)
Gain Error vs Frequency
Closed-Loop Gain = 1000
1
TYPICAL
PRECISION
OP AMP
0.1
GAIN ERROR (%)
0.01
CLOSED-LOOP GAIN
OPEN-LOOP GAIN
1 100
FREQUENCY (Hz)
0.001
GAIN ERROR =
0.1
VS = ±15V
T
R
LT1028/1128 • TPC19
LT1128
LT1028
10
LT1028/1128 • TPC22
= 25°C
A
= 2k
L
LT1028
Gain, Phase vs Frequency
70
60
50
40
30
20
VOLTAGE GAIN (dB)
10
VS = ±15V
0
= 25°C
T
A
C
= 10pF
L
–10
10k 1M 10M 100M
100k
PHASE
GAIN
FREQUENCY (Hz)
LT1028/1128 • TPC20
LT1128
Gain Phase vs Frequency
70
60
50
40
30
20
VOLTAGE GAIN (dB)
10
VS = ±15V
0
= 25°C
T
A
= 10pF
C
L
–10
10k 1M 10M 100M
100k
FREQUENCY (Hz)
PHASE
GAIN
LT1028/1128 • TPC23
70
60
50
40
30
20
10
0
–10
70
60
50
40
30
20
10
0
–10
OVERSHOOT (%)
PHASE MARGIN (DEG)
OVERSHOOT (%)
PHASE MARGIN (DEG)
LT1028
Capacitance Load Handling
80
70
60
50
40
30
20
10
0
R
S
10
30pF
2k
–
+
C
L
AV = –1, RS = 2k
AV = –10
R
= 200Ω
S
AV = –100
= 20Ω
R
S
100 1000 10000
CAPACITIVE LOAD (pF)
LT1128
Capacitance Load Handling
80
70
60
50
40
30
20
10
0
10
30pF
2k
R
S
–
+
C
L
AV = –1, RS = 2k
AV = –10
= 200Ω
R
S
AV = –100, RS = 20Ω
100 1000 10000
CAPACITIVE LOAD (pF)
VS = ±15V
= 25°C
T
A
LT1028/1128 • TPC21
VS = ±15V
= 25°C
T
A
V
= 10mV
O
LT1028/1128 • TPC 24
P-P
Voltage Gain vs Supply Voltage Voltage Gain vs Load Resistance
100
TA = 25°C
RL = 2k
10
VOLTAGE GAIN (V/µV)
1
0
±5
SUPPLY VOLTAGE (V)
R
= 600Ω
L
±10
±15
LT`1028/1128 • TPC25
±20
Maximum Undistorted Output
vs Frequency
100
VS = ±15V
TA = –55°C
10
VOLTAGE GAIN (V/µV)
1
0.1
LOAD RESISTANCE (kΩ)
TA = 25°C
TA = 125°C
I
= 35mA AT –55°C
LMAX
= 27mA AT 25°C
= 16mA AT 125°C
110
LT1028/1128 • TPC26
7
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