LTC1100
Precision, Zero-Drift
Instrumentation Amplifier
U
DESCRIPTIO
FEATURES
■
■
■
■
■
■
■
■
■
■
The LTC®1100 is a high precision instrumentation amplifier
using zero-drift techniques to achieve outstanding DC
performance. The input DC offset is typically 1µV while
the DC offset drift is typically 5nV/°C; a very low bias
current of 65pA is also achieved.
Offset Voltage: 10µV Max
Offset Voltage Drift: 100nV/°C Max
Bias Current: 65pA Max
Offset Current: 65pA Max
Gain Nonlinearity: 20ppm Max
Gain Error: ±0.075% Max
CMRR: 90dB
0.1Hz to 10Hz Noise: 1.9µVP-P
Single 5V Supply Operation
8-Pin MiniDIP
The LTC1100 is self-contained; that is, it achieves a differential gain of 100 without any external gain setting resistor
or trim pot. The gain linearity is 20ppm and the gain drift is
4ppm/°C. The LTC1100 operates from a single 5V supply
up to ±8V. The output typically swings 300mV from its
power supply rails with a 10k load.
U
APPLICATIO S
■
■
■
An optional external capacitor can be added from Pin 7 to
Pin 8 to tailor the device’s 18kHz bandwidth and to
eliminate any unwanted noise pickup.
Thermocouple Amplifiers
Strain Gauge Amplifiers
Differential to Single-Ended Converters
The LTC1100 is also offered in a 16-pin surface mount
package with selectable gains of 10 or 100.
The LTC1100 is manufactured using Linear Technology’s
enhanced LTCMOSTM silicon gate process.
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS is a trademark of Linear Technology Corporation
U
TYPICAL APPLICATIO
Single 5V Supply, DC Instrumentation Amplifier
–VIN
1
8
2
7
3
LTC1100
4
6
5
VOUT
0.01µF
VIN
V+ = 5V
0.1µF
VOUT = 100 [VIN – (–VIN)]
LTC1100 • TA01
1100fc
1
LTC1100
W W
W
AXI U
U
ABSOLUTE
RATI GS
(Note 1)
Operating Temperature Range
LTC1100M/AM (OBSOLETE) ........... −55°C to 125°C
LTC1100C ......................................... −40°C to 85°C
Output Short Circuit Duration ......................... Indefinite
Storage Temperature Range ................ −65°C to 150°C
Total Supply Voltage (V + to V −) ............................. 18V
Input Voltage ....................... (V + + 0.3V) to (V − − 0.3V)
Lead Temperature (Soldering, 10 sec)................. 300°C
U
U
W
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
GND REF 1
8
VOUT
CMRR 2
7
COMP
–VIN 3
6
VIN
V– 4
5
V+
NC 1
LTC1100CN8
16 NC
GND REF 2
N8 PACKAGE
8-LEAD PDIP
TJMAX = 110°C, θJA = 130°C/W
J PACKAGE
8-LEAD CERDIP
TJMAX = 150°C, θJA = 100°C/W
ORDER PART
NUMBER
TOP VIEW
G = 10 3
14 G = 10
CMRR 4
13 COMP
NC 5
12 NC
–VIN 6
11 VIN
V–
LTC1100CJ8
LTC1100AMJ8
LTC1100MJ8
LTC1100CSW
15 VOUT
10 V+
7
NC 8
9
NC
SW PACKAGE
16-LEAD PLASTIC SO WIDE
OBSOLETE PACKAGE
TJMAX = 110°C, θJA = 100°C/W
Consider the N Package for an Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
Gain Error
LTC1100ACN
TYP
MAX
●
Input Offset Voltage
(Note 2)
Input Offset Voltage Drift
(Note 2)
Input Noise Voltage
DC to 10Hz, TA = 25°C
●
0.01
0.075
0.150
±%
±%
3
12
8
30
3
12
20
60
ppm
ppm
±1
±10
±1
±10
µV
±5
±100
±5
±100
Common Mode Rejection Ratio
●
VCM = 2.3V to −4.7V (Note 3)
●
Power Supply Rejection Ratio
VS = ±2.375V to ±8V
●
120
Output Voltage Swing
RL = 2k, VS = ±8V
RL =10k, VS = ±8V
●
●
– 7.2
– 7.7
Supply Current
●
104
1.9
nV/°C
µVP-P
2.5
50
120
2.5
65
135
pA
pA
10
50
10
65
pA
●
Input Offset Current
UNITS
0.05
0.10
1.9
Input Bias Current
LTC1100CN/CJ
TYP
MAX
0.01
●
Gain Nonlinearity
MIN
115
90
110
dB
105
6.2
7.5
2.4
3.4
2.8
4.0
dB
– 7.2
– 7.7
2.4
3.4
6.2
7.5
V
V
3.3
4.5
mA
mA
Internal Sampling Frequency
2.8
2.8
kHz
Bandwidth
18
18
kHz
1100fc
2
LTC1100
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted.
PARAMETER
LTC1100AMJ (Note 4)
MIN
TYP
MAX
CONDITIONS
Gain Error
(Note 2)
Input Offset Voltage Drift
(Note 2)
Input Noise Voltage
DC to 10Hz, TA = 25°C
●
0.01
0.075
0.150
±%
±%
3
8
40
3
20
65
ppm
ppm
±1
±10
±1
±10
µV
±5
±100
±5
±100
nV/°C
1.9
Input Bias Current
5
Input Offset Current
UNITS
0.05
0.11
●
Input Offset Voltage
LTC1100MJ
TYP
MAX
0.01
●
Gain Nonlinearity
MIN
1.9
●
50
300
●
80
5
µVP-P
65
450
pA
pA
120
pA
Common Mode Rejection Ratio
VCM = −4.7V to 2.3V
●
100
90
dB
Power Supply Rejection Ratio
VS = ±2.375V to ±8V
●
115
95
dB
Output Voltage Swing
RL = 10k, VS = ±8V
RL = 2k, VS = ±8V
●
●
– 7.4
– 7.0
Supply Current
7.4
6.0
– 7.4
– 7.0
2.4
2.4
4.2
●
7.4
6.0
V
V
3.3
4.6
mA
mA
Internal Sampling Frequency
2.8
2.8
kHz
Bandwidth
18
18
kHz
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise specified.
PARAMETER
CONDITIONS
Gain Error
TA = 25°C, A V =100
A V =100
A V =10
A V =10
Gain Nonlinearity
TA = 25°C, A V =100
A V =100
A V =10
A V =10
Input Offset Voltage
(Note 2)
Input Offset Voltage Drift
(Note 2)
Input Noise Voltage
DC to 10Hz, TA = 25°C
MIN
LTC1100ACS
TYP
MAX
0.01
0.01
3
12
1
8
30
8
25
±1
±5
0.01
●
●
●
Common Mode Rejection Ratio
Power Supply Rejection Ratio
±%
±%
±%
±%
3
12
1
20
60
10
40
ppm
ppm
ppm
ppm
±10
±1
±10
µV
±100
±5
±100
nV/°C
0.01
●
VCM = −4.7V to 2.3V,
A V =100
A V =10
●
●
104
95
VS = ±2.375V to ±8V
●
120
1.9
µVP-P
2.5
50
120
2.5
65
135
pA
pA
10
50
10
65
pA
●
Input Offset Current
UNITS
0.075
0.150
0.060
0.150
1.9
Input Bias Current
LTC1100CSW
TYP
MAX
0.05
0.10
0.04
0.10
●
●
MIN
115
90
85
105
110
dB
dB
dB
1100fc
3
LTC1100
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, R L = 10k, C C = 1000pF, unless otherwise noted.
PARAMETER
CONDITIONS
Output Voltage Swing
RL=10k, VS = ±8V
RL= 2k, VS = ±8V
●
●
MIN
LTC1100ACS
TYP
MAX
MIN
LTC1100CSW
TYP
MAX
UNITS
– 7.2
– 7.7
6.2
7.5
– 7.2
– 7.7
6.2
7.5
V
V
3.3
4.5
mA
mA
Supply Current
2.4
3.4
●
2.8
4.0
2.4
3.4
Internal Sampling Frequency
2.8
2.8
kHz
Bandwidth
18
180
18
180
kHz
kHz
G = 100
G = 10
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: 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 3: See Applications Information, Single Supply Operation.
Note 4: Please consult Linear Technology Marketing.
W
BLOCK DIAGRA S
2
R
R
14
7
+
99R
5 (V )
99R
2
–
1
3
R
90R
–
9R
4
−
R
13
3
+
–
15
R = 2.5k
+
90R
+
6
8
6
9R
10 (V+)
11
R = 2.5k
+
7 (V – )
4 (V –)
LTC1100 • BD01
LTC1100 • BD02
NOTE: FOR A VOLTAGE GAIN OF 10V/V SHORT PIN 2 TO 3, AND PIN 14 TO 15.
U W
TYPICAL PERFOR A CE CHARACTERISTICS
0.05
DIFFERENTIAL GAIN (dB)
VS = ±8V
RL = 50k
0.03
0.02
0.01
0
–0.01
–50
45
210
40
180
35
PHASE
GAIN
(G = 100)
30
120
25
90
60
20
GAIN
(G = 10)
15
30
10
–25
75
0
25
50
TEMPERATURE (°C)
100
125
5
100
0
1k
10k
100k
–30
1M
FREQUENCY (Hz)
LTC1100 • TPC01
150
LTC1100 • TPC02
25
20
PHASE SHIFT (DEGREES)
GAIN ERROR (±%)
0.04
Gain Nonlinearity
vs Temperature
Gain, Phase vs Frequency
GAIN NONLINEARITY (ppm)
Gain Error vs Temperature
VS = ±8V
RL = 50k
15
10
5
0
–5
–50
–25
75
0
25
50
TEMPERATURE (°C)
100
125
LTC1100 • TPC03
1100fc
4
LTC1100
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Power Supply Rejection Ratio
vs Frequency
Supply Current vs Supply Voltage
150
POWER SUPPLY REJECTION RATIO (dB)
3
TA = 25°C
2
TA = 125°C
1
8
125
100
75
50
25
2
6
10 12 14 16
4
8
TOTAL SUPPLY VOLTAGE V+ TO V – (V)
1k
10
100
FREQUENCY (Hz)
1
LTC1100 • TPC04
G = 100, RC = 100k
CC = 10pF
G = 10, RC = ∞
CC = 0pF
1
40
3
20
6
0
0.1
–
2
±7
VS = ±5V, TA ≤ 85°C
±5 NEGATIVE
±4
±3
±2
+
±1
10k
POSITIVE
VS = ±2.5V, TA ≤ 85°C
NEGATIVE
POSITIVE
0
100k
1
2
3 4 5 6 7 8
LOAD RESISTANCE (kΩ)
Bias Current vs
Common Mode Voltage
60
TA = 25°C
– 60
–120
TA = –55°C
–180
–200
3
4
LTC1100 • TPC10
MOD
NGE
±3
±4
±6
±5
SUPPLY VOLTAGE (V)
±8
±7
VS = ±5V
9
8
RL = 100k
7
RL = 2k
6
5
4
3
2
1
1k
10k
FREQUENCY (Hz)
100k
LTC1100 • TPC09
Internal Sampling Frequency
vs Supply Voltage
4
TA = –55°C
90
75
60
45
30
3
TA = 25°C
2
TA = 125°C
1
15
0
0
–6 –5 –4 –3 –2 –1 0 1 2
COMMON MODE VOLTAGE (V)
ON
E RA
0
100
10
SAMPLING FREQUENCY (kHz)
120
0
9
105
VS = ±5V
TA = 125°C
MM
LTC1100 • TPC06
Voltage Noise vs Frequency
VOLTAGE NOISE DENSITY (nV/ √ Hz)
BIAS CURRENT (pA)
180
E CO
LTC1100 • TPC08
LTC1100 • TPC07
240
ATIV
±2
0
10
100
1k
FREQUENCY (Hz)
MM
Undistorted Output Swing
vs Frequency
POSITIVE
±6
LTC1100
1
NEG
–4
100k
VS = ±8V, TA ≤ 85°C
±8 NEGATIVE
CC
E CO
–2
10
±9
VOUT ± SWING (V)
CMRR (dB)
RC
60
360
10k
±10
120
80
ITIV
NGE
0
Output Voltage Swing vs Load
G = 100, RC = ∞
CC = 0pF
POS
E RA
LTC1100 • TPC05
CMRR vs Frequency
100
2
OD
ON M
–8
0.1
18
4
–6
0
0
TA = 25°C
6
PEAK-TO-PEAK OUTPUT SWING (V)
SUPPLY CURRENT (mA)
TA = –55°C
COMMON MODE RANGE (V)
4
300
Common Mode Range
vs Supply Voltage
10
100
1k
10k
FREQUENCY (Hz)
100k
LTC1100 • TPC11
2
6
10 12 14 16
4
8
TOTAL SUPPLY VOLTAGE V + TO V – (V)
18
LTC1100 • TPC12
1100fc
5
LTC1100
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Large-Signal Transient Response
G = 100, VS = ± 5V
Small-Signal Transient Response
G = 100, VS = ± 5V
Overload Recovery
G = 100, VS = ± 5V
1V/DIV
50mV/DIV
2V/DIV
2V/DIV
10µs/DIV
5µs/DIV
10µs/DIV
LTC1100 • TPC13
LTC1100 • TPC14
Large-Signal Transient Response
G = 10 (LTC1100CS Only), VS = ± 5V
LTC1100 • TPC15
Small-Signal Transient Response
G = 10 (LTC1100CS Only), VS = ± 5V
Overload Recovery
G = 10 (LTC1100CS Only), VS = ± 5V
1V/DIV
50ms/DIV
2V/DIV
2V/DIV
10µs/DIV
10µs/DIV
LTC1100 • TPC16
1µs/DIV
LTC1100 • TPC17
LTC1100 • TPC18
U
U
U
PI FU CTIO S
8-Pin DIP (16-Pin SO)
Pin 1 (2) GND REF: Connect to system ground. This sets
the zero reference for the internal op amps.
Pin 2 (4) CMRR: This pin tailors the gain of the internal
amplifiers to maximize AC CMRR. For applications which
emphasize CMRR requirements, connect a 100k resistor
and a 10pF capacitor in series from CMRR to ground. See
the Applications section.
Pin 3 (6) –VIN: Inverting Input.
Pin 4 (7) V – : Negative Supply.
Pin 5 (10) V + : Positive Supply.
Pin 6 (11) VIN: Noninverting Input.
Pin 7 (13) COMP: This pin reduces the bandwidth of the
internal amplifiers for applications at or near DC. Clock
feedthrough from the internal sampling clock can also be
suppressed by using the COMP pin. The standard compensation circuit is a capacitor from COMP to VOUT, sized
to provide an RC pole with the internal 247k resistor
(22.5k for LTC1100CS in gain-of-10 mode). See the
Applications section.
Pin 8 (15) VOUT: Signal Output.
16-Pin SO Package Only
(3) G = 10: Short to pin (2) for gain of 10. Leave
disconnected for gain of 100.
(14) G = 10: Short to pin (15) for gain of 10. Leave
disconnected for gain of 100.
NOTE: Both pins must be shorted or open to provide
correct gain.
(1),(5),(8),(9),(12),(16) NC: No Internal Connection.
1100fc
6
LTC1100
U
W
U U
APPLICATIO S I FOR ATIO
Common Mode Rejection
Aliasing
Due to very precise matching of the internal resistors, no
trims are required to obtain a DC CMRR of better than
100dB; however, things change as frequency rises. The
inverting amplifier is in a gain of 1.01 (1.1 for gain of 10),
while the noninverting amplifier is in a gain of 99 (9 for gain
of 10). As frequency rises, the higher gain amplifier hits its
gain-bandwidth limit long before the low gain amplifier,
degrading CMRR. The solution is straightforward — slow
down the inverting amplifier to match the noninverting
amp. Figure 1 shows the recommended circuit. The problem is less pronounced in the LTC1100CS in gain-of-10
mode; no CMRR trims are necessary.
The LTC1100 is a chopper-stabilized instrumentation
amplifier; like all sampled systems it exhibits aliasing
behavior for input frequencies at or near the internal
sampling frequency. The LTC1100 incorporates specialized anti-aliasing circuitry which typically attenuates
aliasing products by ≥ 60dB; however, extremely sensitive systems may still have to take precautions to avoid
aliasing errors. For more information, see the LTC1051/
LTC1053 data sheet.
−
3
−
8
LTC1100
+
6
+
2
100k
10pF
LTC1100 • TA02
Figure 1. Improving AC CMRR
Overcompensation
Many instrumentation amplifier applications process DC
or low frequency signals only; consequently, the 18kHz
(180kHz for G = 10) bandwidth of the LTC1100 can be
reduced to minimize system errors or reduce transmitted
clock noise by using the COMP pin. A feedback cap from
COMP to VOUT will react with the 247k internal resistor
(22.5k for G = 10) to limit the bandwidth, as in Figure 2.
Single Supply Operation
The LTC1100 will operate on a single 5V supply, and the
common mode range of the internal op amps includes
ground; single supply operation is limited only by the
output swing of the op amps. The internal inverting
amplifier has a negative saturation limit of 5mV typically,
setting the minimum common mode limit at 5mV/1.01 (or
1.1 for gain of 10). The inputs can be biased above ground,
as shown in Figure 3. Low cost biasing components can be
used since any errors appear as a common mode term and
are rejected.
The minimum differential input voltage is limited by the
swing of the output op amp. Lightly loaded, it will swing
down to 5mV, allowing differential input voltages as low as
50µV (450µV for gain of 10). Single supply operation
limits the LTC1100 to positive differential inputs only;
negative inputs will give a saturated zero output.
5V
5V
RBIAS
6
CB
3
–
+
−
7
LTC1100
6
8
5
LTC1100
SENSOR
3
+
8
OUTPUT
0V TO 5V
4, 1
1N4148
f 3dB =
1
2 π R INT × CB
R INT = 247k FOR G = 100
22.5k FOR G = 10
LTC1100 • TA03
LTC1100 • TA04
Figure 3
Figure 2. Overcompensation to Reduce System Bandwidth
1100fc
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.
7
LTC1100
U
PACKAGE DESCRIPTIO
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
.300 BSC
(7.62 BSC)
.008 – .018
(0.203 – 0.457)
CORNER LEADS OPTION
(4 PLCS)
0° – 15°
.015 – .060
(0.381 – 1.524)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.405
(10.287)
MAX
.005
(0.127)
MIN
.200
(5.080)
MAX
8
NOTE: LEAD DIMENSIONS APPLY TO SOLDER
DIP/PLATE OR TIN PLATE LEADS
.014 – .026
(0.360 – 0.660)
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.045 – .065
(1.143 – 1.651)
6
7
2
3
4
.125
3.175
MIN
.100
(2.54)
BSC
J8 0801
OBSOLETE PACKAGE
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
.045 – .065
(1.143 – 1.651)
(
.400*
(10.160)
MAX
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
+.035
.325 –.015
+0.889
8.255
–0.381
.130 ± .005
(3.302 ± 0.127)
.120
(3.048) .020
MIN
(0.508)
MIN
.018 ± .003
.100
(2.54)
BSC
)
(0.457 ± 0.076)
8
7
6
5
1
2
3
4
NOTE:
1. DIMENSIONS
INCHES
ARE
MILLIMETERS
*THESE DIMENSIONS
DO NOT INCLUDE
MOLD FLASH OR
PROTRUSIONS.
MOLD FLASH OR
PROTRUSIONS
SHALL NOT EXCEED
.010 INCH (0.254mm)
.255 ± .015*
(6.477 ± 0.381)
N8 1002
SW Package
16-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620)
.050 BSC .045 ±.005
.030 ±.005
TYP
.398 – .413
(10.109 – 10.490)
NOTE 4
16
N
15
14
13
12
11 10
9
N
.325 ±.005
.420
MIN
.394 – .419
(10.007 – 10.643)
NOTE 3
1
2
3
N/2
N/2
NOTE:
1. DIMENSIONS IN
RECOMMENDED SOLDER PAD LAYOUT
1
.005
(0.127)
RAD MIN
.291 – .299
(7.391 – 7.595)
NOTE 4
.010 – .029 × 45°
(0.254 – 0.737)
.009 – .013
(0.229 – 0.330)
3
.093 – .104
(2.362 – 2.642)
4
5
6
7
8
.037 – .045
(0.940 – 1.143)
0° – 8° TYP
NOTE 3
.016 – .050
(0.406 – 1.270)
8
2
Linear Technology Corporation
.050
(1.270)
BSC
.014 – .019
(0.356 – 0.482)
TYP
.004 – .012
(0.102 – 0.305)
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON
TOP AND CAVITIES ON THE
BOTTOM OF PACKAGES
ARE THE MANUFACTURING
OPTIONS. THE PART MAY BE
SUPPLIED WITH OR WITHOUT
ANY OF THE OPTIONS.
4. THESE DIMENSIONS DO NOT
INCLUDE MOLD FLASH OR
PROTRUSIONS. MOLD FLASH
OR PROTRUSIONS SHALL NOT
EXCEED .006" (0.15mm)
S16 (WIDE) 0502
1100fc
LW/TP 1202 1K REV C • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 1994