The LT®1881 and LT1882 op amps bring high accuracy
input performance to amplifiers with rail-to-rail output
swing. Input bias currents and capacitive load driving
capabilities are superior to the similar LT1884 and LT1885
amplifiers, at the cost of a slight loss in speed. Input
offset voltage is trimmed to less than 50µV and the low
drift maintains this accuracy over the operating temperature range. Input bias currents are an ultralow 200pA
maximum.
The amplifiers work on any total power supply voltage
between 2.7V and 36V (fully specified from 5V to ±15V).
Output voltage swings to within 40mV of the negative
supply and 220mV of the positive supply make these
amplifiers good choices for low voltage single supply
operation.
Capacitive loads up to 1000pF can be driven directly in
unity-gain follower applications.
The dual LT1881 and LT1881A are available with standard
pinouts in S8 and PDIP packages. The quad LT1882 is in
a 14-pin SO package. For a higher speed device with
similar DC specifications, see the LT1884/LT1885.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
16-Bit Voltage Output DAC on ±5V Supply
1.65k
LT1634
4.096V
+
LT1881
–
5V
–5V
R
COM
LTC®1597
REFR1
U
TC VOS Distribution, Industrial Grade
5V
R
OFS
DAC
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.
Operating Temperature Range (Note 4) .. –40°C to 85°C
Specified Temperature Range (Note 5)... – 40°C to 85°C
–
Maximum Junction Temperature .......................... 150°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
1
OUT A
2
–IN A
3
+IN A
+
4
V
5
+IN B
6
–IN B
7
OUT B
14-LEAD PLASTIC SO
T
JMAX
TOP VIEW
14
13
DA
12
11
10
DB
9
8
S PACKAGE
= 150°C, θJA = 150°C/W
OUT D
–IN D
+IN D
–
V
+IN C
–IN C
OUT C
ORDER PART NUMBER
LT1882CS
LT1882IS
1881
1881I
1881A
1881AI
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Single supply operation VEE = 0, VCC = 5V; VCM = VCC/2 unless otherwise noted. (Note 5)
SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS
V
OS
I
OS
Input Offset Voltage (LT1881A)2550µV
< 70°C●85µV
0°C < T
A
–40°C < T
Input Offset Voltage (LT1881/LT1882)3080µV
0°C < T
–40°C < T
Input Offset Voltage Drift0°C < TA < 70°C●0.30.8µV/°C
(Note 6)–40°C < T
Input Offset Current (LT1881A)100200pA
0°C < T
–40°C < T
Input Offset Current (LT1881/LT1882)150500pA
0°C < T
–40°C < T
< 85°C●110µV
A
< 70°C●125µV
A
< 85°C●150µV
A
< 85°C●0.30.8µV/°C
A
< 70°C●250pA
A
< 85°C●300pA
A
< 70°C●600pA
A
< 85°C●700pA
A
2
LT1881/LT1882
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Single supply operation VEE = 0, VCC = 5V; VCM = VCC/2 unless otherwise noted. (Note 5)
Input Noise Voltage Densityf = 1kHz14nV/√Hz
Input Noise Current Densityf = 1kHz0.03pA/√Hz
Input Voltage RangeVEE + 1.0VCC – 1.0V
1.2V < V
●V
< 3.8V●104dB
CM
+ 1.2VCC – 1.2V
EE
Minimum Operating Supply Voltage●2.42.7V
Large-Signal Voltage GainRL = 10k; 1V < V
RL = 2k; 1V < V
RL = 1k; 1V < V
< 4V5001600V/mV
OUT
< 4V300800V/mV
OUT
< 4V250400V/mV
OUT
●350V/mV
●250V/mV
●200V/mV
Output Voltage Swing LowNo Load●2040mV
I
= 100µA●2550mV
SINK
= 1mA●70150mV
I
SINK
= 5mA●270600mV
I
SINK
Output Voltage Swing HighNo Load●120220mV
(Referred to V
)I
CC
= 100µA●130230mV
SOURCE
I
= 1mA●180300mV
SOURCE
= 5mA●360600mV
I
SOURCE
Supply Current Per AmplifierVCC = 3V0.450.650.85mA
●1.2mA
VCC = 5V0.50.650.9mA
●1.4mA
VCC = 12V0.50.701.0mA
●1.5mA
Short-Circuit CurrentV
Settling Time0.01%, V
Short to GND●1530mA
OUT
Short to V
V
OUT
= –1, RL = 2k
A
V
CC
= 1.5V to 3.5V,30µs
OUT
●1530mA
Slew Rate PositiveAV = –10.150.35V/µs
●0.12V/µs
Slew Rate NegativeAV = –10.110.18V/µs
●0.08V/µs
3
LT1881/LT1882
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Single supply operation VEE = 0, VCC = 5V; VCM = VCC/2 unless otherwise noted. (Note 5)
SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS
∆V
OS
∆IB+Noninverting Bias Current Match(Notes 7, 8)200300pA
Offset Voltage Match (LT1881/LT1882)(Note 7)35125µV
< 70°C●175µV
0°C < T
A
–40°C < T
< 85°C●235µV
A
Offset Voltage Match Drift(Notes 6, 7)●0.41.2µV/°C
(LT1881A)0°C < T
< 70°C●400pA
A
–40°C < T
< 85°C●500pA
A
Noninverting Bias Current Match(Notes 7, 8)250700pA
(LT1881/LT1882)0°C < T
< 70°C●900pA
A
–40°C < T
< 85°C●1000pA
A
(Notes 7, 9)
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Split supply operation VS = ±15V, VCM = 0V unless otherwise noted. (Note 5)
SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS
V
OS
I
OS
I
B
e
n
i
n
V
CM
Input Offset Voltage (LT1881A)2550µV
< 70°C●85µV
0°C < T
A
–40°C < T
< 85°C●110µV
A
Input Offset Voltage (LT1881/LT1882)3080µV
0°C < T
< 70°C●125µV
A
–40°C < T
< 85°C●150µV
A
Input Offset Voltage Drift0°C < TA < 70°C●0.30.8µV/°C
(Note 6)–40°C < T
< 85°C●0.30.8µV/°C
A
Input Offset Current (LT1881A)150200pA
< 70°C●250pA
0°C < T
A
–40°C < T
< 85°C●300pA
A
Input Offset Current (LT1881/LT1882)150500pA
< 70°C●600pA
0°C < T
A
–40°C < T
< 85°C●700pA
A
Input Bias Current (LT1881A)150200pA
0°C < T
< 70°C●250pA
A
–40°C < T
< 85°C●300pA
A
Input Bias Current (LT1881/LT1882)150500pA
< 70°C●600pA
0°C < T
A
–40°C < T
Input Noise Voltage0.1Hz to 10Hz0.5µV
< 85°C●700pA
A
P-P
Input Noise Voltage Densityf = 1kHz14nV/√Hz
Input Noise Current Densityf = 1kHz0.03pA/√Hz
Input Voltage RangeVEE + 1.0VCC – 1.0V
●V
+ 1.2VCC – 1.2V
EE
4
LT1881/LT1882
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Split supply operation VS = ±15V, VCM = 0V unless otherwise noted. (Note 5)
Output Voltage Swing LowNo Load●2040mV
(Referred to V
)I
EE
= 100µA●2550mV
SINK
= 1mA●70150mV
I
SINK
= 5mA●270600mV
I
SINK
Output Voltage Swing HighNo Load●160220mV
(Referred to V
)I
CC
= 100µA●160230mV
SOURCE
I
= 1mA●180300mV
SOURCE
= 5mA●360600mV
I
SOURCE
Supply Current Per AmplifierVS = ±15V0.50.851.1mA
●1.6mA
Short-Circuit CurrentV
Settling Time0.01%, V
Short to V
OUT
V
Short to V
OUT
= –1, RL = 2k
A
V
EE
CC
= –5V to 5V,35µs
OUT
●1540mA
●1530mA
2040mA
2030mA
Slew Rate PositiveAV = –10.210.4V/µs
●0.18V/µs
Slew Rate NegativeAV = –10.130.20V/µs
●0.1V/µs
Offset Voltage Match (LT1881/LT1882)(Note 5)42125µV
< 70°C●175µV
0°C < T
A
–40°C < T
< 85°C●235µV
A
Offset Voltage Match (LT1881A)3570µV
< 70°C●125µV
0°C < T
A
–40°C < T
< 85°C●160µV
A
Offset Voltage Match Drift(Notes 6, 7)●0.41.1µV/°C
(LT1881/LT1882)0°C < T
< 70°C●900pA
A
–40°C < T
< 85°C●1000pA
A
Noninverting Bias Current Match200300pA
(LT1881A)0°C < T
< 70°C●400pA
A
–40°C < T
< 85°C●500pA
A
5
LT1881/LT1882
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
Split supply operation VS = ±15V, VCM = 0V unless otherwise noted. (Note 5)
SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS
∆+PSRRPositive Power Supply Rejection MatchVEE = –15V, VCM = 0V,●108130dB
1.5V < V
∆–PSRRNegative Power Supply Rejection MatchVCC = 15V, VCM = 0V,●104130dB
–1.5V < V
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The inputs are protected by internal resistors and back-to-back
diodes. If the differential input voltage exceeds ±0.7V, the input current
should be limited externally to less than 10mA.
Note 3: A heat sink may be required to keep the junction temperature
below absolute maximum.
Note 4: The LT1881C, LT1882C, LT1881I and LT1882I are guaranteed
functional over the operating temperature range of –40°C to 85°C.
Note 5: The LT1881C and LT1882C are designed, characterized and
expected to meet specified performance from –40°C to 85°C but are not
tested or QA sampled at these temperatures. The LT1881I and LT1882I are
guaranteed to meet specified performance from –40°C to 85°C.
< 18V, (Notes 7, 9)
CC
< –18V, (Notes 7, 9)
EE
Note 6: This parameter is not 100% tested.
Note 7: Matching parameters are the difference between amplifiers
A and B in the LT1881; and between amplifiers A and D and B and C in the
LT1882.
Note 8: This parameter is the difference between the two noninverting
input bias currents.
Note 9:∆CMRR and ∆PSRR are defined as follows: CMRR and PSRR are
measured in µV/V on each amplifier. The difference is calculated in µV/V
and then converted to dB.
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current per Amplifier vs
Supply VoltageSlew Rate vs Supply VoltageSlew Rate vs Temperature
1200
1000
800
600
400
200
SUPPLY CURRENT PER AMPLIFIER (µA)
0
048 12 16 20 24 28 32 36
TOTAL SUPPLY VOLTAGE (V)
125°C
25°C
–55°C
1881/2 G01
SLEW RATE (V/µs)
0.45
AV = –1
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
48 12 16 20 24 28 32 36
0
RISING
FALLING
TOTAL SUPPLY VOLTAGE (V)
1881/2 G02
0.5
0.4
0.3
0.2
SLEW RATE (V/µs)
0.1
0
–25 025 50 75 100 125 150
–50
TEMPERATURE (°C)
RISING
FALLING
VS = ±15V
VS = ±5V
VS = ±15V
VS = ±5V
1881/2 G03
6
LT1881/LT1882
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Gain Bandwidth Product vs
Settling Time vs Output StepSettling Time vs Output Step
10
VS = ±15V
8
A
= –1
V
6
4
2
0
–2
OUTPUT STEP (V)
–4
–6
–8
–10
0.1%0.01%
0.1%0.01%
5 10 15 20 25 30 35 40 45 50 55 60 65
0
SETTLING TIME (µs)
1881/2 G04
10
VS = ±15V
8
A
= 1
V
6
4
0.1%0.01%
2
0
–2
OUTPUT STEP (V)
–4
–6
–8
–10
0.1%0.01%
5 10 15 20 25 30 35 40 45 50 55 60 65
0
SETTLING TIME (µs)
1881/2 G05
Phase Margin vs Supply VoltageGain vs Frequency, AV = –1Gain vs Frequency, AV = 1
60
10
Supply Voltage
900
850
800
750
700
650
GAIN BANDWIDTH PRODUCT (kHz)
600
48 12 16 20 24 28 32 36
0
TOTAL SUPPLY VOLTAGE (V)
10
125°C
25°C
–55°C
1881/2 G06
58
56
54
52
PHASE MARGIN (DEG)
50
48
46
48 12 16 20 24 28 32 36
0
TOTAL SUPPLY VOLTAGE (V)
10
0
–10
GAIN (dB)
–20
–55°C
125°C
125°C
1881/2 G07
Gain vs Frequency with C
AV = 1
VS = ±15V
LOAD
1500pF
1000pF
500pF
,
0pF
0
–10
GAIN (dB)
–20
–30
–40
1k
VS = ±15VVS = ±2.5V
10k100k1M10M100M
FREQUENCY (Hz)
1881/2 G08
Gain vs Frequency with C
AV = –1
10
0
–10
GAIN (dB)
–20
GAIN (dB)
VS = ±15V
–10
–20
–30
–40
0
10k100k1M10M100M
1k
FREQUENCY (Hz)
,
LOAD
1800pF
1000pF
500pF
VS = ±15VVS = ±2.5V
1881/2 G09
–30
–40
10k100k1M10M100M
1k
FREQUENCY (Hz)
1881/2 G10
–30
–40
10k100k1M10M100M
1k
FREQUENCY (Hz)
0pF
1881/2 G11
7
LT1881/LT1882
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Large Signal Response, AV = –1
Large Signal Response, AV = 1
Small Signal Response, AV = –1,
No Load
(5V/DIV)
OUT
V
TIME (50µs/DIV)1881/2 G12
Small Signal Response, AV = –1,
CL = 1000pF
(20mV/DIV)
OUT
V
TIME (2µs/DIV)1881/2 G15
(5V/DIV)
OUT
V
TIME (50µs/DIV)1881/2 G13
Small Signal Response, AV = 1,
RL = 2k
(20mV/DIV)
OUT
V
TIME (2µs/DIV)1881/2 G16
(20mV/DIV)
OUT
V
TIME (2µs/DIV)1881/2 G14
Small Signal Response, AV = 1,
CL = 500pF
(20mV/DIV)
OUT
V
TIME (2µs/DIV)1881/2 G17
8
LT1881/LT1882
U
WUU
APPLICATIOS IFORATIO
The LT1881 dual and LT1882 quad op amps feature
exceptional input precision with rail-to-rail output swing.
The amplifiers are similar to the LT1884 and LT1885
devices. The LT1881 and LT1882 offer superior capacitive
load driving capabilities over the LT1884 and LT1885 in
low voltage gain configurations. Offset voltages are trimmed
to less than 50µV and input bias currents are less than
200pA on the “A” grade devices. Obtaining beneficial
advantage of these precision input characteristics depends upon proper applications circuit design and board
layout.
Preserving Input Precision
Preserving the input voltage accuracy of the LT1881/
LT1882 requires that the applications circuit and PC board
layout do not introduce errors comparable to or greater
than the 30µV offset. Temperature differentials across the
input connections can generate thermocouple voltages of
10’s of microvolts. PC board layouts should keep connections to the amplifier’s input pins close together and away
from heat dissipating components. Air currents across the
board can also generate temperature differentials.
The extremely low input bias currents, 150pA, allow high
accuracy to be maintained with high impedance sources
and feedback networks. The LT1881/LT1882’s low input
bias currents are obtained by using a cancellation circuit
on-chip. This causes the resulting I
uncorrelated, as implied by the IOS specification being
greater than the I
the input resistances in each input lead, as is commonly
recommended with most amplifiers. The impedance at
either input should be kept as small as possible to minimize total circuit error.
. The user should not try to balance
BIAS
BIAS
+ and I
BIAS
– to be
PC board layout is important to insure that leakage currents do not corrupt the low I
precision, high impedance circuits, the input pins should
be surrounded by a guard ring of PC board interconnect,
with the guard driven to the same common mode voltage
as the amplifier inputs.
Input Common Mode Range
The LT1881 and LT1882 outputs are able to swing nearly
to each power supply rail, but the input stage is limited to
operating between VEE + 0.8V and VCC – 0.9V. Exceeding
this common mode range will cause the gain to drop to
zero; however, no gain reversal will occur.
Input Protection
The inverting and noninverting input pins of the LT1881
and LT1882 have limited on-chip protection. ESD protection is provided to prevent damage during handling. The
input transistors have voltage clamping and limiting resistors to protect against input differentials up to 10V. Short
transients above this level will also be tolerated. If the input
pins can see a sustained differential voltage above 10V,
external limiting resistors should be used to prevent
damage to the amplifier. A 1k resistor in each input lead
will provide protection against a 30V differential voltage.
Capacitive Loads
The LT1881 and LT1882 can drive capacitive loads up to
1000pF in unity-gain. The capacitive load driving increases as the amplifier is used in higher gain configurations. Capacitive load driving may be increased by
decoupling the capacitance from the output with a small
resistance.
of the amplifier. In high
BIAS
9
LT1881/LT1882
PACKAGE DESCRIPTIO
U
Dimensions in inches (millimeters) unless otherwise noted.
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.400*
(10.160)
MAX
876
0.255 ± 0.015*
(6.477 ± 0.381)
5
12
0.300 – 0.325
(7.620 – 8.255)
0.065
(1.651)
0.009 – 0.015
(0.229 – 0.381)
+0.035
0.325
–0.015
+0.889
8.255
()
–0.381
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.100
(2.54)
BSC
3
4
0.130 ± 0.005
(3.302 ± 0.127)
0.125
(3.175)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.020
(0.508)
MIN
N8 1098
10
PACKAGE DESCRIPTIO
LT1881/LT1882
U
Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
7
8
5
6
0.228 – 0.244
(5.791 – 6.197)
0.010 – 0.020
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
*
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
×
°
45
0.016 – 0.050
(0.406 – 1.270)
0°– 8° TYP
S Package
14-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
13
14
1
0.337 – 0.344*
(8.560 – 8.738)
12
0.150 – 0.157**
(3.810 – 3.988)
3
2
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
SO8 1298
11
10
8
9
0.228 – 0.244
(5.791 – 6.197)
0.010 – 0.020
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
*
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
× 45°
0° – 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
0.150 – 0.157**
(3.810 – 3.988)
1
3
2
4
5
0.050
(1.270)
BSC
7
6
0.004 – 0.010
(0.101 – 0.254)
S14 1298
11
LT1881/LT1882
TYPICAL APPLICATIO
10k
0.1%
10k
0.1%
U
–50°C to 600°C Digital Thermometer Operates on 3.3V
= 3.3V
V
CC
R
F
1k
V
CC
–
A1
1/2 LT1881
+
R1
4k
R
T
R2
4k
R3
1k
V
CC
–
A2
1/2 LT1881
+
V
CC
V =+ 1.588mV/°C
2
RT: OMEGA F4132 1000Ω RTD
R1, R2, R3, RF: USE BI 698-3 2k × 8 RESISTOR NETWORK
V
REF
+INCLK
LTC1287
–IND
GNDCS/SHDN
V
OUT
CC
1µF
1881/2 TA02
RELATED PARTS
PART NUMBERDESCRIPTIONCOMMENTS
LT1112/LT1114Dual/Quad Picoamp Input Op AmpVOS = 60µV Max
LT1677Gain Programmable Instrumentation AmpGain Error = 0.08% Max
LT1793Low Noise JFET Op AmpIB = 10pA Max
LT1884/LT1885Dual/Quad Picoamp Input Op Amp3 Times Faster than LT1881/LT1882
LTC2050Zero Drift Op Amp in SOT-23VOS = 3µV Max, Rail-to-Rail Output
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear-tech.com
18812i LT/TP 0400 4K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2000
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