LINER LTC1049 Low power zero-drift operational amplifier with internal capacitor Datasheet

LTC1049
Low Power Zero-Drift
Operational Amplifier
with Internal Capacitors
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FEATURES
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DESCRIPTIO
The LTC®1049 is a high performance, low power zero-drift
operational amplifier. The two sample-and-hold capacitors
usually required externally by other chopper stabilized
amplifiers are integrated on the chip. Further, the LTC1049
offers superior DC and AC performance with a nominal
supply current of only 200µA.
Low Supply Current: 200µA
No External Components Required
Maximum Offset Voltage: 10µV
Maximum Offset Voltage Drift: 0.1µV/°C
Single Supply Operation: 4.75V to 16V
Input Common Mode Range Includes Ground
Output Swings to Ground
Typical Overload Recovery Time: 6ms
Available in 8-Pin SO and PDIP Packages
The LTC1049 has a typical offset voltage of 2µV, drift of
0.02µV/°C, 0.1Hz to 10Hz input noise voltage of 3µVP-P
and typical voltage gain of 160dB. The slew rate is 0.8V/µs
with a gain bandwidth product of 0.8MHz.
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APPLICATIO S
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Overload recovery time from a saturation condition is
6ms, a significant improvement over chopper amplifiers
using external capacitors.
4mA to 20mA Current Loops
Thermocouple Amplifiers
Electronic Scales
Medical Instrumentation
Strain Gauge Amplifiers
High Resolution Data Acquisition
The LTC1049 is available in a standard 8-pin plastic dual
in line, as well as an 8-pin SO package. The LTC1049 can
be a plug-in replacement for most standard op amps with
improved DC performance and substantial power savings.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
Single Supply Thermocouple Amplifier
0.068µF
VIN = 5V
246k
1k
2
2
7
LTC1049
K
®
LT 1025A
GND
4
–
R–
5
7
3
–
+
+
6
VOUT = 0V TO 4V
FOR 0°C TO 400°C
4
0.1µF
TYPE K
SUPPLY CURRENT = 280µA
LTC1049 • TA01
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LTC1049
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ABSOLUTE
RATI GS
(Note 1)
Total Supply Voltage (V + to V –) ............................... 18V
Input Voltage (Note 2) .......... (V + + 0.3V) to (V – – 0.3V)
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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PACKAGE/ORDER I FOR ATIO
TOP VIEW
NC 1
8
NC
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
NC
ORDER PART
NUMBER
LTC1049CN8
NC
–IN 1
+IN 2
V– 3
N8 PACKAGE 8-LEAD PDIP
TJMAX = 110°C, θJA = 130°C/W
J8 PACKAGE 8-LEAD CERDIP
TJMAX = 150°C, θJA = 100°C/W
TOP VIEW
–
+
NC
8
V+
7
OUT
6
NC
LTC1049CS8
5
4
LTC1049CJ8
ORDER PART
NUMBER
S8 PART MARKING
S8 PACKAGE
8-LEAD PLASTIC SO
1049
TJMAX = 110°C, θJA = 200°C/W
OBSOLETE PACKAGE
Consider the N8 Package as an Alternate Source
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±5V, unless noted.
PARAMETER
Input Offset Voltage
Average Input Offset Drift
Long Term Offset Voltage Drift
Input Offset Current
CONDITIONS
(Note 3)
(Note 3)
MIN
●
●
±15
Input Bias Current
●
Input Noise Voltage
Input Noise Current
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Large-Signal Voltage Gain
Maximum Output Voltage Swing
0.1Hz to 10Hz
0.1Hz to 1Hz
f = 10Hz (Note 4)
VCM = V – to 2.7V
VS = ±2.375V to ±8V
RL = 100kΩ, VOUT = ±4.75V
RL = 10kΩ
●
●
●
●
Slew Rate
Gain Bandwidth Product
Supply Current
RL = 100kΩ
RL = 10kΩ, CL = 50pF
●
No Load
TYP
±2
±0.02
50
±30
110
110
130
–4.6/3.2
±4.9
±100
±150
±50
±150
3
1
2
130
130
160
–4.9/4.2
±4.97
0.8
0.8
200
●
Internal Sampling Frequency
MAX
±10
±0.1
700
330
495
UNITS
µV
µV/°C
nV√mo
pA
pA
pA
pA
µV P-P
µV P-P
fA√Hz
dB
dB
dB
V
V
V
V/µs
MHz
µA
µA
Hz
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LTC1049
ELECTRICAL CHARACTERISTICS
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: Connecting any terminal to voltages greater than V + or less than
V – may cause destructive latch-up. It is recommended that no sources
operating from external supplies be applied prior to power-up of the
LTC1049.
Note 3: These parameters are guaranteed by design. Thermocouple effects
preclude measurement of these voltage levels in high speed automatic test
systems. VOS is measured to a limit determined by test equipment
capability.
Note 4: Current Noise is calculated from the formula:
IN = √(2q • Ib)
where q = 1.6 • 10–19 Coulomb.
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TYPICAL PERFOR A CE CHARACTERISTICS
Common Mode Input Range vs
Supply Voltage
Voltage Noise vs Frequency
140
8
60
40
20
2
0
1k
10k
PHASE
GAIN
–4
0
180
–6
–20
200
0
1
FREQUENCY (Hz)
4
5
2
3
6
SUPPLY VOLTAGE (±V)
7
8
–40
100
Supply Current vs Supply Voltage
SHORT-CIRCUIT OUTPUT CURRENT (mA)
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
300
200
100
5
6
7 8 9 10 11 12 13 14 15
TOTAL SUPPLY VOLTAGE (V)
LTC1049 • TPC04
0
–50 –25
220
10M
1.2
400
100
1M
Output Short-Circuit Current vs
Supply Voltage
500
160
10k
100k
FREQUENCY (Hz)
LTC1049 • TPC03
Supply Current vs Temperature
400
220
1k
LTC1049 • TPC02
LTC1049 • TP01
280
140
40
160
100k
340
120
60
20
–2
–8
100
10
100
80
4
VOLTAGE GAIN (dB)
COMMON MODE VOLTAGE (V)
80
80
PHASE SHIFT (DEGREES)
100
60
VS = ± 5V
100 NO LOAD
VCM = V –
6
120
VOLTAGE NOISE (nV/√Hz)
Gain/Phase vs Frequency
120
50
25
0
75
TEMPERATURE (°C)
100
125
LTC1049 • TPC05
0.8
0.4
≈
≈
0
–3
–6
–9
4
14
8
10
12
6
TOTAL SUPPLY VOLTAGE, V+ TO V–(V)
16
LTC1049 • TPC06
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LTC1049
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TYPICAL PERFOR A CE CHARACTERISTICS
Sampling Frequency vs
Supply Voltage
Sampling Frequency vs
Temperature
5
3000
CMRR vs Frequency
160
VS = ± 5V
VS = ± 5V
2500
2000
1500
4
120
3
CMRR (dB)
SAMPLING FREQUENCY (kHz)
SAMPLING FREQUENCY (Hz)
140
2
100
80
60
40
1
20
1000
4
14
16
6
8
10
12
TOTAL SUPPLY VOLTAGE, V + TO V – (V)
0
50
25
0
75 100
–50 –25
AMBIENT TEMPERATURE (°C)
125
0
1
10
100
1k
FREQUENCY (Hz)
10k
LTC1049 • TPC09
LTC1049 • TPC08
LTC1049 • TPC07
Small-Signal Transient
Response
Overload Recovery
100k
Large-Signal Transient
Response
400mV
0V
2V/DIV
OUTPUT
0V
INPUT
0.2V/DIV
100mV
STEP
6V
STEP
1µs/DIV
5µs/DIV
–5V
AV = –100
VS = ±5V
0.5ms/DIV
LTC1049 • TPC10
AV = 1
RL = 10k
CL = 50pF
VS = ±5V
LTC1049 • TPC11
AV = 1
RL = 10k
CL = 50pF
VS = ±5V
LTC1049 • TPC12
LTC1049 DC to 1Hz Noise
VS = ± 5V
1Hz NOISE
1µV/DIV
NOISE VOLTAGE
1µV/DIV
10s/DIV
LTC1049 • TPC13
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LTC1049
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TYPICAL PERFOR A CE CHARACTERISTICS
LTC1049 DC to 10Hz Noise
VS = ± 5V
NOISE VOLTAGE
1µV/DIV
10Hz NOISE
1µV/DIV
1s/DIV
LTC1049•TPC14
TEST CIRCUITS
Electrical Characteristics Test Circuit
DC to 10Hz and DC to 1Hz Noise Test Circuit
140
8
COMMON MODE VOLTAGE (V)
120
VOLTAGE NOISE (nV/√Hz)
VCM = V –
6
100
80
60
40
4
2
0
–2
–4
–6
20
–8
10
100
1k
10k
100k
FREQUENCY (Hz)
LTC1049 • TP01
0
1
4
5
2
3
6
SUPPLY VOLTAGE (±V)
7
8
LTC1049 • TPC02
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LTC1049
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APPLICATIO S I FOR ATIO
ACHIEVING PICOAMPERE/MICROVOLT
PERFORMANCE
Picoamperes
In order to realize the picoampere level of accuracy of the
LTC1049, proper care must be exercised. Leakage
currents in circuitry external to the amplifier can significantly degrade performance. High quality insulation should
be used (e.g., Teflon™, Kel-F); cleaning of all insulating
surfaces to remove fluxes and other residues will probably
be necessary—particularly for high temperature performance. Surface coating may be necessary to provide a
moisture barrier in high humidity environments.
Board leakage can be minimized by encircling the input
connections with a guard ring operated at a potential close
to that of the inputs: in inverting configurations, the guard
ring should be tied to ground; in noninverting connections, to the inverting input. Guarding both sides of the
printed circuit board is required. Bulk leakage reduction
depends on the guard ring width.
Microvolts
Thermocouple effects must be considered if the LTC1049’s
ultralow drift is to be fully utilized. Any connection of
dissimilar metals forms a thermoelectric junction producing an electric potential which varies with temperature
(Seebeck effect). As temperature sensors, thermocouples
exploit this phenomenon to produce useful information. In
low drift amplifier circuits the effect is a primary source of
error.
Connectors, switches, relay contacts, sockets, resistors,
solder, and even copper wire are all candidates for thermal
EMF generation. Junctions of copper wire from different
manufacturers can generate thermal EMFs of 200nV/°C —
twice the maximum drift specification of the LTC1049. The
copper/kovar junction, formed when wire or printed circuit
traces contact a package lead, has a thermal EMF of
approximately 35µV/°C—300 times the maximum drift
specification of the LTC1049.
Minimizing thermal EMF-induced errors is possible if
judicious attention is given to circuit board layout and
component selection. It is good practice to minimize the
number of junctions in the amplifier’s input signal path.
Avoid connectors, sockets, switches, and relays where
possible. In instances where this is not possible, attempt
to balance the number and type of junctions so that
differential cancellation occurs. Doing this may involve
deliberately introducing junctions to offset unavoidable
junctions.
PACKAGE-INDUCED OFFSET VOLTAGE
Package-induced thermal EMF effects are another important source of errors. It arises at the copper/kovar
junctions formed when wire or printed circuit traces
contact a package lead. Like all the previously mentioned
thermal EMF effects, it is outside the LTC1049’s offset
nulling loop and cannot be cancelled. The input offset
voltage specification of the LTC1049 is actually set by the
package-induced warm-up drift rather than by the circuit
itself. The thermal time constant ranges from 0.5 to 3
minutes, depending on package type.
LOW SUPPLY OPERATION
The minimum supply for proper operation of the LTC1049
is typically below 4.0V (±2.0V). In single supply applications, PSRR is guaranteed down to 4.7V (±2.35V) to
ensure proper operation down to the minimum TTL
specified voltage of 4.75V.
PIN COMPATIBILITY
The LTC1049 is pin compatible with the 8-pin versions of
7650, 7652 and other chopper-stabilized amplifiers. The
7650 and 7652 require the use of two external capacitors
connected to Pins 1 and 8 which are not needed for the
LTC1049. Pins 1, 5, and 8 of the LTC1049 are not connected internally; thus, the LTC1049 can be a direct plugin for the 7650 and 7652, even if the two capacitors are left
on the circuit board.
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LTC1049
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TYPICAL APPLICATIO S
Low Power, Low Hold Step Sample-and-Hold
5V
13
2
4.5
6
LTC201
VIN
S/H
3
LTC1049
2
1
–
5V
7
3
+
0.47µF
MYLAR
4
VOUT
DROOP ≤ 1mV/s
HOLD STEP ≤ 20µV
IS = 250µA TYP
LTC1049 • TA02
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LTC1049
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TYPICAL APPLICATIO S
Low Power, Single Supply, Low Offset Instrumentation Amp
5V
198k
2k
2
–
– VIN
+
198k
2
7
LTC1049
3
2k
6
–
7
LTC1049
3
4
+
6
VOUT
4
+ VIN
GAIN = 100
IS = 400µA
CMRR ≥ 60dB, WITH 0.1% RESISTORS (RESISTORS LIMITED)
LTC1049 • TA03
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LTC1049
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PACKAGE DESCRIPTIO
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.005
(0.127)
MIN
.405
(10.287)
MAX
8
7
6
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
2
.300 BSC
(7.62 BSC)
3
4
.200
(5.080)
MAX
.015 – .060
(0.381 – 1.524)
.008 – .018
(0.203 – 0.457)
0° – 15°
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.045 – .065
(1.143 – 1.651)
.014 – .026
(0.360 – 0.660)
.100
(2.54)
BSC
.125
3.175
MIN
J8 0801
OBSOLETE PACKAGE
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LTC1049
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PACKAGE DESCRIPTIO
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.400*
(10.160)
MAX
8
7
6
5
1
2
3
4
.255 ± .015*
(6.477 ± 0.381)
.300 – .325
(7.620 – 8.255)
.008 – .015
(0.203 – 0.381)
(
+.035
.325 –.015
8.255
+0.889
–0.381
)
.045 – .065
(1.143 – 1.651)
.130 ± .005
(3.302 ± 0.127)
.065
(1.651)
TYP
.100
(2.54)
BSC
.120
(3.048) .020
MIN
(0.508)
MIN
.018 ± .003
(0.457 ± 0.076)
N8 1002
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)
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LTC1049
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PACKAGE DESCRIPTIO
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
.050 BSC
8
.245
MIN
7
6
5
.160 ±.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
1
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
× 45°
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
.053 – .069
(1.346 – 1.752)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
NOTE:
1. DIMENSIONS IN
.014 – .019
(0.355 – 0.483)
TYP
INCHES
(MILLIMETERS)
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)
2
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
SO8 0303
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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.
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LTC1049
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TYPICAL APPLICATIO
Thermocouple-Based Temperature to Frequency Converter
6V
K
–
– +
1M
Q2
2N3906
LTC1049
GND
R
–
l1
+
6.81k*
Q1
2N3904
NC
10k
100k
LT1025
6V
0.02µF
TYPE K
THERMOCOUPLE
V+
l2
100k
C1
100pF
C3
0.47µF
1.5k
l3
OUTPUT
0 – 100°C =
0 – 1kHz
C4
300pF
240k
6V
100°C
TRIM
+
LT1004 – 1.2
6.8µF
9
16
15
11
14
C2
390pF †
S1
IS = 360µA
SUPPLY RANGE = 4.5V to 10V
S2
3
*IRC/TRW–MTR–5/+120ppm
†POLYSTYRENE
= 74C14
S3
2
10
S4
6
7
LTC201
1
8
LTC1049 • TA04
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Linear Technology Corporation
LT 0406 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1991
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