LT1028/LT1128
1
1028fd
For more information www.linear.com/LT1028
TYPICAL APPLICATION
FEATURES DESCRIPTION
Ultralow Noise Precision
High Speed Op Amps
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.
L, LT, LTC , LT M, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Ultralow Noise 1M TIA Photodiode Amplifier
APPLICATIONS
n Voltage Noise
1.1nV/√Hz Max at 1kHz
0.85nV/√Hz Typ at 1kHz
1.0nV/√Hz Typ at 10Hz
35nVP-P Typ, 0.1Hz to 10Hz
n Voltage and Current Noise 100% Tested
n Gain-Bandwidth Product
LT1028: 50MHz Min
LT1128: 13MHz Min
n Slew Rate
LT1028: 11V/µs Min
LT1128: 5V/µs Min
n Offset Voltage: 40µV Max
n Drift with Temperature: 0.8µV/°C Max
n Voltage Gain: 7 Million Min
n Available in 8-Lead SO Package
n Low Noise Frequency Synthesizers
n High Quality Audio
n Infrared Detectors
n Accelerometer and Gyro Amplifiers
n 350Ω Bridge Signal Conditioning
n Magnetic Search Coil Amplifiers
n Hydrophone Amplifiers
Voltage Noise vs Frequency
FREQUENCY (Hz)
1
0.1
1
10
10 100
1028 TA02
VOLTAGE NOISE DENSITY (nV/√Hz)
0.1
1k
1/f CORNER = 3.5Hz
1/f CORNER = 14Hz
TYPICAL
MAXIMUM
VS = 15V
TA = 25°C
+
–VOUT = ~0.4V + IPD
• 1M
VS–
VS–
VS+
LT1028
0.1µF
JFET
NXP
BF862
PHOTO
DIODE
SFH213
D
S
4.32k
1028 TA01
1M
0.5pF
4.99k
VS = ±15V
LT1028/LT1128
2
1028fd
For more information www.linear.com/LT1028
ABSOLUTE MAXIMUM RATINGS
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
(Note 1)
TOP VIEW
V+
VOS TRIM
–IN
OUT
OVER-
COMP
+IN
V–
(CASE)
8
7
5
3
2
1
4
H PACKAGE
8-LEAD TO-5 METAL CAN
V
OS TRIM
+
–6
TJMAX = 175°C, θJA = 140°C/W, θJC = 40°C/W
OBSOLETE PACKAGE
1
2
3
4 5
6
7
8
TOP VIEW
–IN
+IN
V–
S8 PACKAGE
8-LEAD PLASTIC SOIC
V+
OUT
+
–
VOS
TRIM
VOS
TRIM
OVER-
COMP
TJMAX = 150°C, θJA = 140°C/W
N8 PACKAGE
8-LEAD PLASTIC DIP
1
2
3
4 5
6
7
8
TOP VIEW
–IN
+IN
V–
V+
OUT
+
–
OVER-
COMP
VOS
TRIM
VOS
TRIM
TJMAX = 150°C, θJA = 150°C/W
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
OVER-
COMP
+
–
TJMAX = 150°C, θJA = 130°C/W
NOTE: THIS DEVICE IS NOT RECOMMENDED FOR NEW DESIGNS
J8 PACKAGE
8-LEAD CERAMIC DIP
TJMAX = 175°C, θJA = 140°C/W, θJC = 40°C/W
OBSOLETE PACKAGE
PIN CONFIGURATION
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
LT1028/LT1128
3
1028fd
For more information www.linear.com/LT1028
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE
LT1028ACN8#PBF N/A LT1028ACN8 8-Lead PDIP 0°C to 70°C
LT1028CN8#PBF N/A LT1028CN8 8-Lead PDIP 0°C to 70°C
LT1128ACN8#PBF N/A LT1128ACN8 8-Lead PDIP 0°C to 70°C
LT1128CN8#PBF N/A LT1128CN8 8-Lead PDIP 0°C to 70°C
LT1028CS8#PBF LT1028CS8#TRPBF 1028 8-Lead Plastic Small Outline 0°C to 70°C
LT1128CS8#PBF LT1128CS8#TRPBF 1128 8-Lead Plastic Small Outline 0°C to 70°C
LT1028CSW#PBF LT1028CSW#TRPBF LT1028CSW 16-Lead Plastic SOIC (Wide) 0°C to 70°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
ELECTRICAL CHARACTERISTICS
VS = ±15V, TA = 25°C unless otherwise noted.
LT1028AM/AC
LT1128AM/AC
LT1028M/C
LT1128M/C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
VOS Input Offset Voltage (Note 2) 10 40 20 80 µV
∆VOS
∆Time Long Term Input Offset
Voltage Stability (Note 3) 0.3 0.3 µV/Mo
IOS Input Offset Current VCM = 0V 12 50 18 100 nA
IBInput Bias Current VCM = 0V ±25 ±90 ±30 ±180 nA
enInput Noise Voltage 0.1Hz to 10Hz (Note 4) 35 75 35 90 nVP-P
Input Noise Voltage Density fO = 10Hz (Note 5)
fO = 1000Hz, 100% Tested 1.00
0.85 1.7
1.1 1.0
0.9 1.9
1.2 nV/√Hz
nV/√Hz
InInput Noise Current Density fO = 10Hz (Notes 4 and 6)
fO = 1000Hz, 100% Tested 4.7
1.0 10.0
1.6 4.7
1.0 12.0
1.8 pA/√Hz
pA/√Hz
Input Resistance
Common Mode
Differential Mode
300
20
300
20
MΩ
kΩ
Input Capacitance 5 5 pF
Input Voltage Range ±11.0 ±12.2 ±11.0 ±12.2 V
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
AVOL Large-Signal Voltage Gain RL ≥ 2k, VO = ±12V
RL ≥ 1k, VO = ±10V
RL ≥ 600Ω, VO = ±10V
7.0
5.0
3.0
30.0
20.0
15.0
5.0
3.5
2.0
30.0
20.0
15.0
V/µV
V/µV
V/µV
VOUT Maximum Output Voltage Swing RL ≥ 2k
RL ≥ 600Ω ±12.3
±11.0 ±13.0
±12.2 ±12.0
±10.5 ±13.0
±12.2 V
V
SR Slew Rate AVCL = –1 LT1028
AVCL = –1 LT1128 11.0
5.0 15.0
6.0 11.0
4.5 15.0
6.0 V/µs
V/µs
GBW Gain-Bandwidth Product fO = 20kHz (Note 7) LT1028
fO = 200kHz (Note 7) LT1128 50
13 75
20 50
11 75
20 MHz
MHz
ZOOpen-Loop Output Impedance VO = 0, IO = 0 80 80 Ω
ISSupply Current 7.4 9.5 7.6 10.5 mA
LT1028/LT1128
4
1028fd
For more information www.linear.com/LT1028
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the operating temperature range 0°C ≤ TA ≤ 70°C. VS = ±15V, unless otherwise
noted.
LT1028AC
LT1128AC
LT1028C
LT1128C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
VOS Input Offset Voltage (Note 2) l15 80 30 125 µV
∆VOS
∆Temp Average Input Offset Drift (Note 8) l0.1 0.8 0.2 1.0 µV/°C
IOS Input Offset Current VCM = 0V l15 65 22 130 nA
IBInput Bias Current VCM = 0V l±30 ±120 ±40 ±240 nA
Input Voltage Range l±10.5 ±12.0 ±10.5 ±12.0 V
CMRR Common Mode Rejection Ratio VCM= ±10.5V l110 124 106 124 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±18V l114 132 107 132 dB
AVOL Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V
RL ≥ 1k, VO = ±10V
l5.0
4.0 25.0
18.0 3.0
2.5 25.0
18.0 V/µV
V/µV
VOUT Maximum Output Voltage Swing RL ≥ 2k
RL ≥ 600Ω (Note 10)
l±11.5
±9.5 ±12.7
±11.0 ±11.5
±9.0 ±12.7
±10.5 V
V
ISSupply Current l8.0 10.5 8.2 11.5 mA
The l denotes the specifications which apply over the operating
temperature range –55°C ≤ TA ≤ 125°C. VS = ±15V, unless otherwise noted.
LT1028AM
LT1128AM
LT1028M
LT1128M
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
VOS Input Offset Voltage (Note 2) l30 120 45 180 µV
∆VOS
∆Temp Average Input Offset Drift (Note 8) l0.2 0.8 0.25 1.0 µV/°C
IOS Input Offset Current VCM = 0V l25 90 30 180 nA
IBInput Bias Current VCM = 0V l±40 ±150 ±50 ±300 nA
Input Voltage Range l±10.3 ±11.7 ±10.3 ±11.7 V
CMRR Common Mode Rejection Ratio VCM = ±10.3V l106 122 100 120 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±16V l110 130 104 130 dB
AVOL Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V
RL ≥ 1k, VO = ±10V
l3.0
2.0 14.0
10.0 2.0
1.5 14.0
10.0 V/µV
V/µV
VOUT Maximum Output Voltage Swing RL ≥ 2k l±10.3 ±11.6 ±10.3 ±11.6 V
ISSupply Current l8.7 11.5 9.0 13.0 mA
LT1028/LT1128
5
1028fd
For more information www.linear.com/LT1028
LT1028AC
LT1128AC
LT1028C
LT1128C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
VOS Input Offset Voltage l20 95 35 150 µV
∆VOS
∆Temp Average Input Offset Drift (Note 8) l0.2 0.8 0.25 1.0 µV/°C
IOS Input Offset Current VCM = 0V l20 80 28 160 nA
IBInput Bias Current VCM = 0V l±35 ±140 ±45 ±280 nA
Input Voltage Range l±10.4 ±11.8 ±10.4 ±11.8 V
CMRR Common Mode Rejection Ratio VCM = ±10.5V l108 123 102 123 dB
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±18V l112 131 106 131 dB
AVOL Large-Signal Voltage Gain RL ≥ 2k, VO = ±10V
RL ≥ 1k, VO = ±10V
l4.0
3.0 20.0
14.0 2.5
2.0 20.0
14.0 V/µV
V/µV
VOUT Maximum Output Voltage Swing RL ≥ 2k l±11.0 ±12.5 ±11.0 ±12.5 V
ISSupply Current l8.5 11.0 8.7 12.5 mA
The l denotes the specifications which apply over the operating
temperature range –40°C ≤ TA ≤ 85°C. VS = ±15V, unless otherwise noted. (Note 11)
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Input Offset Voltage measurements are performed by automatic
test equipment approximately 0.5 sec. after application of power. In
addition, at TA = 25°C, offset voltage is measured with the chip heated
to 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 VOS
during the first 30 days are typically 2.5µV.
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
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 TA
= 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.
ELECTRICAL CHARACTERISTICS
LT1028/LT1128
6
1028fd
For more information www.linear.com/LT1028
TYPICAL PERFORMANCE CHARACTERISTICS
10Hz Voltage Noise Distribution
Total Noise vs Matched Source
Resistance
Total Noise vs Unmatched Source
Resistance Current Noise Spectrum
0.01Hz to 1Hz Voltage Noise Voltage Noise vs Temperature
0.1Hz to 10Hz Voltage Noise
Wideband Noise, DC to 20kHz
Wideband Voltage Noise
(0.1Hz to Frequency Indicated)
0.6
0
NUMBER OF UNITS
20
60
80
100
1.0 1.4 1.8
180
1028 G01
40
0.8 1.2
120
140
160
1.6 2.0
2.2
8
70
148
158
57
28
742322 2
1321 1 1
VS = ±15V
TA = 25°C
500 UNITS
MEASURED
FROM 4 RUNS
VOLTAGE NOISE DENSITY (nV/√Hz)
1028 G02
VERTICAL SCALE = 0.5µV/DIV
HORIZONTAL SCALE = 0.5ms/DIV
BANDWIDTH (Hz)
100
0.1
1
100k 1M
0.01
10k1k
VS = ±15V
TA = 25°C
MATCHED SOURCE RESISTANCE (Ω)
1
TOTAL NOISE DENSITY (nV/√Hz)
10
100
3 1k
10k
1028 G04
1
0.1
VS = ±15V
TA = 25°C
10 30 100 300 3k
AT 10Hz
2 RS NOISE ONLY
AT 1kHz
–
+
RS
RS
UNMATCHED SOURCE RESISTANCE (Ω)
1
TOTAL NOISE DENSITY (nV/√Hz)
10
100
3 1k
10k
1028 G05
1
0.1
VS = ±15V
TA = 25°C
10 30 100 300 3k
AT 10Hz
2 RS NOISE ONLY
AT 1kHz
RS
FREQUENCY (Hz)
10
0.1
CURRENT NOISE DENSITY (pA/√Hz)
1
10
100
100 1k
10k
1028 G06
MAXIMUM
TYPICAL
1/f CORNER = 800Hz
1/f CORNER = 250Hz
TIME (SEC)
0 8
1028 G07
246
10
10nV
VS = ±15V
TA = 25°C
TIME (SEC)
0 80
1028 G08
20 40 60
100
10nV
VS = ±15V
TA = 25°C
TEMPERATURE (°C)
–50
0
RMS VOLTAGE DENSITY (nV/√Hz)
0.8
2.0
050 75
1028 G09
O.4
1.6
1.2
–25 25 100 125
VS = ±15V
AT 10Hz
AT 1kHz
LT1028/LT1128
7
1028fd
For more information www.linear.com/LT1028
TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs TemperatureVoltage Noise vs Supply Voltage
Bias Current Over the Common
Mode RangeWarm-Up Drift
Output Short-Circuit Current
vs Time
Distribution of Input Offset
Voltage
Input Bias and Offset Currents
Over Temperature
Long-Term Stability of Five
Representative Units
Offset Voltage Drift with Temperature
of Representative Units
OFFSET VOLTAGE (µV)
–50
UNITS (%)
12
16
20
30
1028 G10
8
4
0–30 –10 10
50
10
14
18
6
2
20
–40 –20 040
VS = ±15V
TA = 25°C
800 UNITS TESTED
FROM FOUR RUNS
TEMPERATURE (°C)
–50
–50
OFFSET VOLTAGE (µV)
–40
–20
–10
0
50
20
050 75
1028 G11
–30
30
40
10
–25 25 100
125
VS = ±15V
TIME (MONTHS)
0
OFFSET VOLTAGE CHANGE (µV)
2
6
10
4
1028 G12
–2
–6
–10 123
5
0
4
8
–4
–8
VS = ±15V
TA = 25°C
t = 0 AFTER 1 DAY PRE-WARM UP
TIME AFTER POWER ON (MINUTES)
0
0
CHANGE IN OFFSET VOLTAGE (µV)
4
8
12
16
20
24
1 2 3 4
1028 G13
5
VS = ±15V
TA = 25°C
METAL CAN (H) PACKAGE
DUAL-IN-LINE PACKAGE
PLASTIC (N) OR CERDIP (J)
TEMPERATURE (°C)
–50
INPUT BIAS AND OFFSET CURRENTS (nA)
40
50
60
25 75
1028 G14
30
20
–25 0 50 100
125
10
0
VS = ±15V
VCM = 0V
BIAS CURRENT
OFFSET CURRENT
COMMON MODE INPUT VOLTAGE (V)
–15
–80
INPUT BIAS CURRENT (nA)
–60
–20
0
20
–5 5
15
100
1028 G15
–40
–10 0
40
60
80
10
RCM = 20V
65nA ª 300MΩ VS = ±15V
TA = 25°C
POSITIVE INPUT CURRENT
(UNDERCANCELLED) DEVICE
NEGATIVE INPUT CURRENT
(OVERCANCELLED) DEVICE
TEMPERATURE (°C)
–50
0
SUPPLY CURRENT (mA)
1
3
4
5
10
7
050 75
1028 G17
2
8
9
6
–25 25 100 125
VS = ±15V
VS = ±5V
TIME FROM OUTPUT SHORT TO GROUND (MINUTES)
0
–50
SINKING
–40
–20
–10
0
50
20
2
1028 G18
–30
30
40
10
13
SHORT-CIRCUIT CURRENT (mA)
SOURCING
VS = ±15V
–50°C
25°C
125°C
–50°C
125°C
25°C
SUPPLY VOLTAGE (V)
0
RMS VOLTAGE NOISE DENSITY (nV/√Hz)
1.0
1.25
±15
1028 G16
0.75
0.5 ±5 ±10
±20
1.5
TA = 25°C
AT 10Hz
AT 1kHz
LT1028/LT1128
8
1028fd
For more information www.linear.com/LT1028
TYPICAL PERFORMANCE CHARACTERISTICS
Gain Error vs Frequency
Closed-Loop Gain = 1000
LT1128
Gain Phase vs Frequency
LT1028
Gain, Phase vs Frequency
Voltage Gain vs Frequency
Voltage Gain vs Supply Voltage Voltage Gain vs Load Resistance
Maximum Undistorted Output
vs Frequency
LT1128
Capacitance Load Handling
LT1028
Capacitance Load Handling
FREQUENCY (Hz)
0.01
–20
VOLTAGE GAIN (dB)
160
1028 G19
140
120
100
80
60
40
20
0
0.1 1 10 100 1k 10k 100k 1M 10M
100M
LT1128 LT1028
VS = ±15V
TA = 25°C
RL = 2k
FREQUENCY (Hz)
10
VOLTAGE GAIN (dB)
20
40
50
70
10k 1M 10M 100M
1028 G20
–10
100k
60
30
0
VS = ±15V
TA = 25°C
CL = 10pF
GAIN
PHASE
10
20
40
50
70
–10
60
30
0
PHASE MARGIN (DEG)
CAPACITIVE LOAD (pF)
10
40
OVERSHOOT (%)
50
60
70
80
100 1000
10000
1028 G21
30
20
10
0
VS = ±15V
TA = 25°C
–
+
CL
2k
30pF
RS
AV = –1, RS = 2k
AV = –100
RS = 20Ω
AV = –10
RS = 200Ω
FREQUENCY (Hz)
0.1
0.001
GAIN ERROR (%)
0.01
0.1
1
1
100
1028 G22
LT1128
LT1028
TYPICAL
PRECISION
OP AMP
GAIN ERROR = CLOSED-LOOP GAIN
OPEN-LOOP GAIN
10
FREQUENCY (Hz)
10
VOLTAGE GAIN (dB)
20
40
50
70
10k 1M 10M 100M
1028 G23
–10 100k
60
30
0VS = ±15V
TA = 25°C
CL = 10pF
GAIN
PHASE
10
20
40
50
70
–10
60
30
0
PHASE MARGIN (DEG)
CAPACITIVE LOAD (pF)
10
40
OVERSHOOT (%)
50
60
70
80
100 1000
10000
1028 G24
30
20
10
0
VS = ±15V
TA = 25°C
VO = 10mVP-P
AV = –1, RS = 2k
–
+
CL
2k
30pF
RS
AV = –10
RS = 200Ω
AV = –100, RS = 20Ω
SUPPLY VOLTAGE (V)
5
1
10
100
10 15
1028 G25
VOLTAGE GAIN (V/µV)
02
0
TA = 25°C
RL = 2k
RL = 600Ω
LOAD RESISTANCE (kΩ)
0.1
1
VOLTAGE GAIN (V/µV)
10
100
1
10
1028 G26
VS = ±15V
TA = –55°C TA = 25°C
TA = 125°C
ILMAX = 35mA AT –55°C
= 27mA AT 25°C
= 16mA AT 125°C
FREQUENCY (Hz)
10k
5
PEAK-TO-PEAK OUTPUT VOLTAGE (V)
20
25
30
100k 1M
10M
1028 G27
15
10
LT1128 LT1028
VS = ±15V
TA = 25°C
RL = 2k
LT1028/LT1128
9
1028fd
For more information www.linear.com/LT1028
TYPICAL PERFORMANCE CHARACTERISTICS
LT1128
Large-Signal Transient Response
LT1028
Slew Rate, Gain-Bandwidth
Product Over Temperature
LT1128
Slew Rate, Gain-Bandwidth
Product Over Temperature
LT1028
Slew Rate, Gain-Bandwidth Product
vs Over-Compensation Capacitor
LT1128
Slew Rate, Gain-Bandwidth Product
vs Over-Compensation Capacitor Closed-Loop Output Impedance
LT1128
Small-Signal Transient Response
LT1028
Large-Signal Transient Response
LT1028
Small-Signal Transient Response
1028 G28
1µs/DIV
5V/DIV
10V
–10V
A
V
= –1, R
S
= R
F
= 2k, C
F
= 15pF
1028 G29
0.2µs/DIV
20mV/DIV
50mV
–50mV
AV = –1, RS = RF = 2k,
C
F
= 15pF, C
L
= 80pF
TEMPERATURE (°C)
–50
SLEW RATE (V/µs)
16
17
18
25 75
1028 G30
15
14
–25 0 50 100 125
13
12
VS = ±15V
70
80
90
60
50
40
30
GAIN-BANDWIDTH PRODUCT (f
O
= 20kHz), (MHz)
GBW
FALL
RISE
1028 G31
2µs/DIV
0V
10V
–10V
A
V
= –1, R
S
= R
F
= 2k, C
F
= 30pF
1028 G32
0.2µs/DIV
0V
50mV
–50mV
AV = –1, CL = 10pF
TEMPERATURE (°C)
–50
0
SLEW RATE (V/µs)
1
3
4
5
050 100
9
1028 G33
2
–25 25
6
7
8
75 125
20
10
30
GAIN-BANDWIDTH PRODUCT (f
O
= 200kHz), (MHz)
FALL
RISE
GBW
FREQUENCY (Hz)
10
OUTPUT IMPEDANCE (Ω)
1
10
100
100k
1028 G34
0.1
0.01
0.001 100 1k 10k
1M
IO = 1mA
VS = ±15V
TA = 25°C LT1128
LT1028
LT1128
LT1028
AV = 1000
AV = 5
OVER-COMPENSATION CAPACITOR (pF)
1
SLEW RATE (V/µs)
10
1 100 1000 10000
0.1 10
100
10
100
1
1k
GAIN AT 200kHz
GBW
SLEW RATE
OVER-COMPENSATION CAPACITOR (pF)
1
10
1 100 1000 10000
1028 G35
0.1 10
100
10
100
1k
GBW
SLEW RATE
1
OVER-COMPENSATION CAPACITOR (pF)
1
SLEW RATE (V/µs)
10
1 100 1000 10000
1028 G36
0.1 10
100
1k
10k
GAIN AT 20kHz
COC FROM PIN 5 TO PIN 6
VS = ±15V
TA = 25°C
SLEW GBW
100
10
LT1028/LT1128
10
1028fd
For more information www.linear.com/LT1028
TYPICAL PERFORMANCE CHARACTERISTICS
LT1128
Total Harmonic Distortion vs
Closed-Loop Gain
Common Mode Limit Over
Temperature
LT1028
Total Harmonic Distortion vs
Frequency and Load Resistance
Common Mode Rejection Ratio
vs Frequency
Power Supply Rejection Ratio
vs Frequency
High Frequency Voltage Noise
vs Frequency
LT1028
Total Harmonic Distortion vs
Closed-Loop Gain
LT1128
Total Harmonic Distortion vs
Frequency and Load Resistance
TEMPERATURE (°C)
–50
V–
COMMON MODE LIMIT (V)
REFERRED TO POWER SUPPLY
1
3
4
V
+
–3
050 75
1028 G37
2
–2
–1
–4
–25 25 100 125
VS = ±5V
VS = ±5V TO ±15V
VS = ±15V
FREQUENCY (Hz)
10
80
100
120
10k 1M
1028 G38
60
40
100 1k 100k
10M
20
0
COMMON MODE REJECTION RATIO (dB)
140
VS = ±15V
TA = 25°C
LT1128 LT1028
FREQUENCY (Hz)
0.1
POWER SUPPLY REJECTION RATIO (dB)
80
100
120
10M
1028 G39
60
40
010 1k 100k
20
160
140
1M
1100 10k
VS = ±15V
TA = 25°C
NEGATIVE
SUPPLY
POSITIVE
SUPPLY
FREQUENCY (kHz)
1
0.001
TOTAL HARMONIC DISTORTION (%)
0.01
0.1
10
100
1028 G40
AV = 1000
RL = 600Ω
AV = 1000
RL = 2k
VO = 20VP-P
VS = ±15V
TA = 25°C
AV = –1000
RL = 2k
AV = 1000
RL = 600Ω
CLOSED LOOP GAIN
0.001
TOTAL HARMONIC DISTORTION (%)
0.01
10 1k 10k
100k
1028 G41
0.0001 100
0.1
VO = 20VP-P
f = 1kHz
VS = ±15V
TA = 25°C
RL = 10k
NON-INVERTING
GAIN
INVERTING
GAIN
MEASURED
EXTRAPOLATED
FREQUENCY (Hz)
10k
0.1
1.0
10
100k
1M
1028 G42
NOISE VOLTAGE DENSITY (nV/√Hz)
FREQUENCY (kHz)
1.0
0.001
TOTAL HARMONIC DISTORTION (%)
0.1
1.0
10
100
1028 G43
0.01
AV = 1000
RL = 600Ω
AV = –1000
RL = 2k
VO = 20VP-P
VS = ±15V
TA = 25°C
AV = 1000
RL = 609Ω
AV = 1000
RL = 2k
CLOSED LOOP GAIN
0.001
TOTAL HARMONIC DISTORTION (%)
0.01
10 1k 10k
100k
1028 G44
0.0001 100
0.1
VO = 20VP-P
f = 1kHz
VS = ±15V
TA = 25°C
RL = 10k
NON-INVERTING
GAIN
INVERTING
GAIN
MEASURED
EXTRAPOLATED
LT1028/LT1128
11
1028fd
For more information www.linear.com/LT1028
APPLICATIONS INFORMATION – NOISE
Voltage Noise vs Current Noise
The LT1028/LT1128’s less than 1nV/√Hz voltage noise is
three times better than the lowest voltage noise heretofore
available (on the LT1007/1037). A necessary condition for
such low voltage noise is operating the input transistors at
nearly 1mA of collector currents, because voltage noise is
inversely proportional to the square root of the collector
current. Current noise, however, is directly proportional
to the square root of the collector current. Consequently,
the LT1028/LT1128’s current noise is significantly higher
than on most monolithic op amps.
Therefore, to realize truly low noise performance it is
important to understand the interaction between voltage
noise (en), current noise (In) and resistor noise (rn).
Total Noise vs Source Resistance
The total input referred noise of an op amp is given by:
et = [en2 + rn2 + (InReq)2]1/2
where Req is the total equivalent source resistance at the
two inputs, and
rn = √4kTReq = 0.13√Req in nV/√Hz at 25°C
As a numerical example, consider the total noise at 1kHz
of the gain 1000 amplifier shown in Figure 1.
the largest term, as in the example above, and the LT1028/
LT1128’s voltage noise becomes negligible. As Req is
further increased, current noise becomes important. At
1kHz, when Req is in excess of 20k, the current noise
component is larger than the resistor noise. The total
noise versus matched source resistance plot illustrates
the above calculations.
The plot also shows that current noise is more dominant
at low frequencies, such as 10Hz. This is because resistor
noise is flat with frequency, while the 1/f corner of current
noise is typically at 250Hz. At 10Hz when Req > 1k, the
current noise term will exceed the resistor noise.
When the source resistance is unmatched, the total noise
versus unmatched source resistance plot should be con-
sulted. Note that total noise is lower at source resistances
below 1k because the resistor noise contribution is less.
When RS > 1k total noise is not improved, however. This
is because bias current cancellation is used to reduce
input bias current. The cancellation circuitry injects two
correlated current noise components into the two inputs.
With matched source resistors the injected current noise
creates a common-mode voltage noise and gets rejected
by the amplifier. With source resistance in one input only,
the cancellation noise is added to the amplifier’s inherent
noise.
In summary, the LT1028/LT1128 are the optimum am-
plifiers for noise performance, provided that the source
resistance is kept low. The following table depicts which op
amp manufactured by Linear Technology should be used
to minimize noise, as the source resistance is increased
beyond the LT1028/LT1128’s level of usefulness.
Table 1. Best Op Amp for Lowest Total Noise vs Source Resistance
SOURCE RESIS-
TANCE (Ω) (Note 1)
BEST OP AMP
AT LOW FREQ (10Hz) WIDEBAND (1kHz)
0 to 400 LT1028/LT1128 LT1028/LT1128
400 to 4k LT1007/1037 LT1028/LT1128
4k to 40k LT1001 LT1007/LT1037
40k to 500k LT1012 LT1001
500k to 5M LT1012 or LT1055 LT1012
>5M LT1055 LT1055
Note 1: Source resistance is defined as matched or unmatched, e.g.,
RS = 1k means: 1k at each input, or 1k at one input and zero at the other.
Req = 100Ω + 100Ω || 100k ≈ 200Ω
rn = 0.13√200 = 1.84nV√Hz
en = 0.85nV√Hz
In = 1.0pA/√Hz
et = [0.852 + 1.842 + (1.0 × 0.2)2]1/2 = 2.04nV/√Hz
Output noise = 1000 et = 2.04µV/√Hz
At very low source resistance (Req < 40Ω) voltage noise
dominates. As Req is increased resistor noise becomes
–
+
100Ω 100k
100Ω
LT1028
LT1128
1028 F01
Figure 1
LT1028/LT1128
12
1028fd
For more information www.linear.com/LT1028
APPLICATIONS INFORMATION – NOISE
Noise Testing – Voltage Noise
The LT1028/LT1128’s RMS voltage noise density can be
accurately measured using the Quan Tech Noise Analyzer,
Model 5173 or an equivalent noise tester. Care should be
taken, however, to subtract the noise of the source resistor
used. Prefabricated test cards for the Model 5173 set the
device under test in a closed-loop gain of 31 with a 60Ω
source resistor and a 1.8k feedback resistor. The noise
of this resistor combination is 0.13√58 = 1.0nV/√Hz. An
LT1028/LT1128 with 0.85nV/√Hz noise will read (0.852 +
1.02)1/2 = 1.31nV/√Hz. For better resolution, the resistors
should be replaced with a 10Ω source and 300Ω feedback
resistor. Even a 10Ω resistor will show an apparent noise
which is 8% to 10% too high.
The 0.1Hz to 10Hz peak-to-peak noise of the LT1028/
LT1128 is measured in the test circuit shown. The fre-
quency response of this noise tester indicates that the
0.1Hz corner is defined by only one zero. The test time
to measure 0.1Hz to 10Hz noise should not exceed 10
seconds, as this time limit acts as an additional zero to
eliminate noise contributions from the frequency band
below 0.1Hz.
Measuring the typical 35nV peak-to-peak noise per-
formance of the LT1028/LT1128 requires special test
precautions:
(a) The device should be warmed up for at least five
minutes. As the op amp warms up, its offset voltage
changes typically 10µV due to its chip temperature
increasing 30°C to 40°C from the moment the power
supplies are turned on. In the 10 second measurement
interval these temperature-induced effects can easily
exceed tens of nanovolts.
(b) For similar reasons, the device must be well shielded
from air current to eliminate the possibility of ther-
moelectric effects in excess of a few nanovolts, which
would invalidate the measurements.
(c) Sudden motion in the vicinity of the device can also
feedthrough to increase the observed noise.
A noise-voltage density test is recommended when measur-
ing noise on a large number of units. A 10Hz noise-voltage
density measurement will correlate well with a 0.1Hz to
10Hz peak-to-peak noise reading since both results are
determined by the white noise and the location of the 1/f
corner frequency.
Figure 2. 0.1Hz to 10Hz Noise Test Circuit Figure 3. 0.1Hz to 10Hz Peak-to-Peak
Noise Tester Frequency Response
–
+
VOLTAGE GAIN = 50,000
* DEVICE UNDER TEST
NOTE ALL CAPACITOR VALUES ARE FOR
NONPOLARIZED CAPACITORS ONLY
100k
10Ω
–
+
2k
4.7µF
0.1µF
100k
24.3k
22µF
2.2µF
4.3k
110k
SCOPE
× 1
RIN
= 1M
0.1µF
*
1028 F02
LT1001
FREQUENCY (Hz)
40
GAIN (dB)
60
70
90
100
0.01 1.0 10 100
1028 F03
30 0.1
50
80
LT1028/LT1128
13
1028fd
For more information www.linear.com/LT1028
APPLICATIONS INFORMATION – NOISE
Noise Testing – Current Noise
Current noise density (In) is defined by the following for-
mula, and can be measured in the circuit shown in Figure 4.
ln=
eno2−31• 18.4nV/ Hz
( )
2
20k • 31
1/2
If the Quan Tech Model 5173 is used, the noise reading is
input-referred, therefore the result should not be divided
by 31; the resistor noise should not be multiplied by 31.
100% Noise Testing
The 1kHz voltage and current noise is 100% tested on
the LT1028/LT1128 as part of automated testing; the
approximate frequency response of the filters is shown.
The limits on the automated testing are established by
extensive correlation tests on units measured with the
Quan Tech Model 5173.
10Hz voltage noise density is sample tested on every lot.
Devices 100% tested at 10Hz are available on request for
an additional charge.
10Hz current noise is not tested on every lot but it can be
inferred from 100% testing at 1kHz. A look at the current
noise spectrum plot will substantiate this statement. The
only way 10Hz current noise can exceed the guaranteed
limits is if its 1/f corner is higher than 800Hz and/or its
white noise is high. If that is the case then the 1kHz test
will fail.
Figure 5. Automated Tester Noise Filter
–
+
e
no
1.8k
60Ω LT1028
LT1128
10k
10k
1028 F04
FREQUENCY (Hz)
100
–50
NOISE FILTER LOSS (dB)
–10
0
10
1k 10k
100k
1028 F05
–20
–40
–30
CURRENT
NOISE
VOLTAGE
NOISE
Figure 4
LT1028/LT1128
14
1028fd
For more information www.linear.com/LT1028
Figure 7. Test Circuit for Offset Voltage
and Offset Voltage Drift with Temperature
–
+
R
F
1028 F08
OUTPUT 6V/µs
–
+
–15V
10k*
200Ω* LT1028
LT1128
1028 F07
10k*
VO = 100VOS
* RESISTORS MUST HAVE LOW
THERMOELECTRIC POTENTIAL
VO
6
7
2
4
3
15V
APPLICATIONS INFORMATION
General
The LT1028/LT1128 series devices may be inserted directly
into OP-07, OP-27, OP-37, LT1007 and LT1037 sockets
with or without removal of external nulling components. In
addition, the LT1028/LT1128 may be fitted to 5534 sockets
with the removal of external compensation components.
Offset Voltage Adjustment
The input offset voltage of the LT1028/LT1128 and its drift
with temperature, are permanently trimmed at wafer test-
ing to a low level. However, if further adjustment of VOS is
necessary, the use of a 1k nulling potentiometer will not
degrade drift with temperature. Trimming to a value other
than zero creates a drift of (VOS/300)µV/°C, e.g., if VOS
is adjusted to 300µV, the change in drift will be 1µV/°C.
The adjustment range with a 1k pot is approximately
±1.1mV.
Unity-Gain Buffer Applications (LT1128 Only)
When RF ≤ 100Ω and the input is driven with a fast, large-
signal pulse (>1V), the output waveform will look as shown
in the pulsed operation diagram (Figure 8).
–
+
6
1k
INPUT
LT1028
LT1128
1028 F06
7
8
1
2
3
4
OUTPUT
–15V
15V
Figure 6
Figure 8
Offset Voltage and Drift
Thermocouple effects, caused by temperature gradients
across dissimilar metals at the contacts to the input termi-
nals, can exceed the inherent drift of the amplifier unless
proper care is exercised. Air currents should be minimized,
package leads should be short, the two input leads should
be close together and maintained at the same temperature.
The circuit shown in Figure 7 to measure offset voltage
is also used as the burn-in configuration for the LT1028/
LT1128.
During the fast feedthrough-like portion of the output, the
input protection diodes effectively short the output to the
input and a current, limited only by the output short-circuit
protection, will be drawn by the signal generator. With
RF ≥ 500Ω, the output is capable of handling the current
requirements (IL ≤ 20mA at 10V) and the amplifier stays
in its active mode and a smooth transition will occur.
As with all operational amplifiers when RF > 2k, a pole will
be created with RF and the amplifier’s input capacitance,
creating additional phase shift and reducing the phase
margin. A small capacitor (20pF to 50pF) in parallel with
RF will eliminate this problem.
LT1028/LT1128
15
1028fd
For more information www.linear.com/LT1028
APPLICATIONS INFORMATION
Frequency Response
The LT1028’s Gain, Phase vs Frequency plot indicates that
the device is stable in closed-loop gains greater than +2 or
–1 because phase margin is about 50° at an open-loop gain
of 6dB. In the voltage follower configuration phase margin
seems inadequate. This is indeed true when the output is
shorted to the inverting input and the noninverting input
is driven from a 50Ω source impedance. However, when
feedback is through a parallel R-C network (provided CF
< 68pF), the LT1028 will be stable because of interaction
between the input resistance and capacitance and the
feedback network. Larger source resistance at the non-
inverting input has a similar effect. The following voltage
follower configurations are stable:
Another configuration which requires unity-gain stability
is shown below. When CF is large enough to effectively
short the output to the input at 15MHz, oscillations can
occur. The insertion of RS2 ≥ 500Ω will prevent the LT1028
from oscillating. When RS1 ≥ 500Ω, the additional noise
contribution due to the presence of RS2 will be minimal.
When RS1 ≤ 100Ω, RS2 is not necessary, because RS1
represents a heavy load on the output through the CF
short. When 100Ω < RS1 < 500Ω, RS2 should match RS1.
For example, RS1 = RS2 = 300Ω will be stable. The noise
increase due to RS2 is 40%.
If CF is only used to cut noise bandwidth, a similar effect
can be achieved using the over-compensation terminal.
The Gain, Phase plot also shows that phase margin is
about 45° at gain of 10 (20dB). The following configuration
has a high (≈70%) overshoot without the 10pF capacitor
because of additional phase shift caused by the feedback
resistor – input capacitance pole. The presence of the 10pF
capacitor cancels this pole and reduces overshoot to 5%.
1028 F09
–
+
33pF
2k
LT1028
50Ω
–
+
LT1028
50Ω
500Ω
1028 F10
C1
R1
RS1
RS2 LT1028
–
+
1028 F11
10pF
10k
50Ω
1.1k –
+
LT1028
Figure 9
Over-Compensation
The LT1028/LT1128 are equipped with a frequency over-
compensation terminal (Pin 5). A capacitor connected
between Pin 5 and the output will reduce noise bandwidth.
Details are shown on the Slew Rate, Gain-Bandwidth Prod-
uct vs Over-Compensation Capacitor plot. An additional
benefit is increased capacitive load handling capability.
Figure 10
Figure 11
LT1028/LT1128
16
1028fd
For more information www.linear.com/LT1028
Low Noise Voltage Regulator
1028 TA04
10µF
2k
20V OUTPUT
–
+
LT1028
121Ω
PROVIDES PRE-REG
AND CURRENT
LIMITING
10µF
+
28V
2.32k
2k
330Ω
1000pF
1k
28V
LT317A
OUT
ADJ
IN
LT1021-10
2N6387
TYPICAL APPLICATIONS
Strain Gauge Signal Conditioner with Bridge Excitation
1028 TA03
1µF
REFERENCE
OUTPUT
–
+
LT1128
30.1k*
49.9Ω*
15V
330Ω
10k
ZERO
TRIM
5.0V
301k*
LT1021-5
0V TO 10V
OUTPUT
3
2
7
6
4
350Ω
BRIDGE
–15V
15V
15V
LT1028
–
+
3
2
7
6
4
–15V
LT1028
–
+
3
2
7
6
4
–15V
5k
GAIN
TRIM
330Ω
*RN60C FILM RESISTORS
THE LT1028’s NOISE CONTRIBUTION IS NEGLIGIBLE
COMPARED TO THE BRIDGE NOISE.
LT1028/LT1128
17
1028fd
For more information www.linear.com/LT1028
TYPICAL APPLICATIONS
Paralleling Amplifiers to Reduce Voltage Noise
1028 TA05
–
+1.5k
A1
LT1028
470Ω
OUTPUT
–
+
7.5Ω
4.7k
–
+1.5k
470Ω
7.5Ω
–
+1.5k
470Ω
7.5Ω
A2
LT1028
An
LT1028
LT1028
OUTPUT NOISE
n • 200
2µV
√5
1. ASSUME VOLTAGE NOISE OF LT1028 AND 7.5Ω SOURCE RESISTOR = 0.9nV/√Hz.
2. GAIN WITH n LT1028s IN PARALLEL = n • 200.
3. OUTPUT NOISE = √n • 200 • 0.9nV/√Hz.
4. INPUT REFERRED NOISE = = nV/√Hz.
5. NOISE CURRENT AT INPUT INCREASES √n TIMES.
6. IF n = 5, GAIN = 1000, BANDWIDTH = 1MHz, RMS NOISE, DC TO 1MHz = = 0.9µV.
0.9
√n
LT1028/LT1128
18
1028fd
For more information www.linear.com/LT1028
Tape Head Amplifier
Phono Preamplifier
TYPICAL APPLICATIONS
1028 TA06
0.1µF
10Ω
–15V
10k
–
+
LT1028
OUTPUT
787Ω
0.33µF
100pF
47k
MAG PHONO
INPUT
4
6
7
15V
2
3
ALL RESISTORS METAL FILM
1028 TA07
0.1µF
10Ω –
+
LT1028
OUTPUT
499Ω
TAPE HEAD
INPUT
6
31.6k
2
3
ALL RESISTORS METAL FILM
LT1028/LT1128
19
1028fd
For more information www.linear.com/LT1028
Low Noise, Wide Bandwidth Instrumentation Amplifier
Gyro Pick-Off Amplifier
TYPICAL APPLICATIONS
1028 TA08
10Ω
–
+
LT1028
OUTPUT
820Ω
+INPUT
68pF
10k
50Ω
68pF
820Ω
–
+
LT1028
–INPUT
–
+
LT1028
300Ω
300Ω 10k
GAIN = 1000, BANDWIDTH = 1MHz
INPUT REFERRED NOISE = 1.5nV/√Hz AT 1kHz
WIDEBAND NOISE –DC to 1MHz = 3µVRMS
IF BW LIMITED TO DC TO 100kHz = 0.55µV
RMS
1028 TA09
100Ω
OUTPUT TO SYNC
DEMODULATOR
1k
–
+
LT1028
SINE
DRIVE
•
GYRO TYPICAL–
NORTHROP CORP.
GR-F5AH7-5B
LT1028/LT1128
20
1028fd
For more information www.linear.com/LT1028
1028 TA10
–
+
LT1028
C2
0.047
R2
R1
C1
0.047
2k
20Ω
20Ω 2k
10pF
5.6k
15µF
+
22k
10k
–
+
LT1055
1VRMS OUTPUT
1.5kHz TO 15kHz
WHERE R1C1 = R2C2
f = 1
2πRC
( )
MOUNT 1N4148s
IN CLOSE PROXIMITY
TRIM FOR
LOWEST
DISTORTION
100k
10k
20k
2N4338
560Ω
2.4k
4.7k
LT1004-1.2V
15V
<0.0018% DISTORTION AND NOISE.
MEASUREMENT LIMITED BY RESOLUTION OF
HP339A DISTORTION ANALYZER
1028 TA11
–
+
LT1052
10Ω
0.1
30k
10k
15V
7
6
4
2
3
8
1
–15V
0.1 0.01
15V
68Ω
–
+
LT1028
130Ω
1
7
8
4
–15V
INPUT
OUTPUT
1N758
1N758
100k
2
3
TYPICAL APPLICATIONS
Super Low Distortion Variable Sine Wave Oscillator
Chopper-Stabilized Amplifier
LT1028/LT1128
21
1028fd
For more information www.linear.com/LT1028
SCHEMATIC DIAGRAM
1.5µA
1
NULL
R5
130Ω
R6
130Ω
R1
3k
R2
3k
3
8
NULL
Q4
C1
257pF
900µA 900µA
Q6
Q5
Q9
Q8
Q7
Q2 4.5µA
4.5µA
1.5µA
Q13 Q14
Q1
4.5µA
NON-
INVERTING
INPUT
0
1.8mA
Q3
BIAS
2
INVERTING
INPUT
4
V–
R7
80Ω
Q11
Q10
Q12
300µA
Q15
Q21
5OVER-COMP
Q23
600µA
R12
240Ω
C4
35pF
Q22
R11
100Ω
C3
250pF
Q19
Q18
Q16
Q17 R11
400Ω
R10
400Ω
1.1mA 2.3mA 400µA
V+
7
R10
500Ω C2
Q26
Q25
Q24 6
OUTPUT
Q27
1028 TA12
4.5µA
3131
Q20
R8
480Ω
500µA
C2 = 50pF for LT1028
C2 = 275pF for LT1128
LT1028/LT1128
22
1028fd
For more information www.linear.com/LT1028
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LT1028#packaging for the most recent package drawings.
OBSOLETE PACKAGE
J8 0801
.014 – .026
(0.360 – 0.660)
.200
(5.080)
MAX
.015 – .060
(0.381 – 1.524)
.125
3.175
MIN
.100
(2.54)
BSC
.300 BSC
(7.62 BSC)
.008 – .018
(0.203 – 0.457) 0° – 15°
.005
(0.127)
MIN
.405
(10.287)
MAX
.220 – .310
(5.588 – 7.874)
1 2 34
8 7 6 5
.025
(0.635)
RAD TYP
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
CORNER LEADS OPTION
(4 PLCS)
.045 – .065
(1.143 – 1.651)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
J8 Package
3-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
LT1028/LT1128
23
1028fd
For more information www.linear.com/LT1028
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LT1028#packaging for the most recent package drawings.
N8 REV I 0711
.065
(1.651)
TYP
.045 – .065
(1.143 – 1.651)
.130 ±.005
(3.302 ±0.127)
.020
(0.508)
MIN
.018 ±.003
(0.457 ±0.076)
.120
(3.048)
MIN
.008 – .015
(0.203 – 0.381)
.300 – .325
(7.620 – 8.255)
.325 +.035
–.015
+0.889
–0.381
8.255
( )
1 2 34
87 65
.255 ±.015*
(6.477 ±0.381)
.400*
(10.160)
MAX
NOTE:
1. DIMENSIONS ARE
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
.100
(2.54)
BSC
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
LT1028/LT1128
24
1028fd
For more information www.linear.com/LT1028
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LT1028#packaging for the most recent package drawings.
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
SO8 REV G 0212
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1234
.150 – .157
(3.810 – 3.988)
NOTE 3
8765
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN .160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030
±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
LT1028/LT1128
25
1028fd
For more information www.linear.com/LT1028
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LT1028#packaging for the most recent package drawings.
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0° – 8° TYP
.008 – .010
(0.203 – 0.254)
1
N
2345678
N/2
.150 – .157
(3.810 – 3.988)
NOTE 3
16 15 14 13
.386 – .394
(9.804 – 10.008)
NOTE 3
.228 – .244
(5.791 – 6.197)
12 11 10 9
S16 REV G 0212
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
.245
MIN
N
1 2 3 N/2
.160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
S Package
16-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
LT1028/LT1128
26
1028fd
For more information www.linear.com/LT1028
PACKAGE DESCRIPTION
OBSOLETE PACKAGE
Please refer to http://www.linear.com/product/LT1028#packaging for the most recent package drawings.
.050
(1.270)
MAX
.016 – .021**
(0.406 – 0.533)
.010 – .045*
(0.254 – 1.143)
SEATING
PLANE
.040
(1.016)
MAX .165 – .185
(4.191 – 4.699)
GAUGE
PLANE
REFERENCE
PLANE
.500 – .750
(12.700 – 19.050)
.305 – .335
(7.747 – 8.509)
.335 – .370
(8.509 – 9.398)
DIA
.230
(5.842)
TYP
.027 – .045
(0.686 – 1.143)
.028 – .034
(0.711 – 0.864)
.110 – .160
(2.794 – 4.064)
INSULATING
STANDOFF
45°
H8 (TO-5) 0.230 PCD 0204
LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND THE SEATING PLANE
FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS .016 – .024
(0.406 – 0.610)
*
**
PIN 1
H Package
8-Lead TO-5 Metal Can (.230 Inch PCD)
(Reference LTC DWG # 05-08-1321)
LT1028/LT1128
27
1028fd
For more information www.linear.com/LT1028
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
REVISION HISTORY
REV DATE DESCRIPTION PAGE NUMBER
B 10/12 Replaced the Typical Application. 1
C 10/14 Corrected diagram to show N8 package is not obsolete.
Changed TJMAX to 150°C for S8 and SW packages.
Corrected right-hand Electrical Characteristics column to reflect non-A-grade specs.
Corrected LM301A and LT1012 input polarity.
2
2
3
28
D 10/15 Corrected component values in Low Noise Voltage Regulator circuit. 16
(Revision history begins at Rev B)
LT1028/LT1128
28
1028fd
For more information www.linear.com/LT1028
LINEAR TECHNOLOGY CORPORATION 1992
LT 1015 REV D • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT1028
RELATED PARTS
TYPICAL APPLICATION
PART NUMBER DESCRIPTION COMMENTS
LT1806/LT1807 325MHz, 3.5nV/√Hz Single and Dual Op Amps Slew Rate = 140V/µs, Low Distortion at 5MHz: –80dBc
Low Noise Infrared Detector
1028 TA13
10Ω
1M
1k
10k
5V
–
+
LT1028
7
6
4
2
3
8
–5V
1000µF
DC OUT
5V
39Ω
33Ω
+
267Ω
10Ω
+
+
OPTICAL
CHOPPER
WHEEL
IR
RADIATION
PHOTO-
ELECTRIC
PICK-OFF
INFRA RED ASSOCIATES, INC.
HgCdTe IR DETECTOR
13Ω AT 77°K
1/4 LTC1043
30pF
100µF
100µF
13
14 16
10k* 10k*
SYNCHRONOUS
DEMODULATOR
+
–
LT1012
7
4
2
3
–5V
6
5V
1
8
12 +
–
LM301A
7
4
2
3
–5V
6
5V
1
8