LT1996
Precision, 100µA
Gain Selectable Amplifier
FEATURES
■
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DESCRIPTIO
■
■
■
■
■
■
■
■
■
■
Pin Configurable as a Difference Amplifier,
Inverting and Noninverting Amplifier
Difference Amplifier
Gain Range 9 to 117
CMRR >80dB
Noninverting Amplifier
Gain Range 0.008 to 118
Inverting Amplifier
Gain Range –0.08 to –117
Gain Error: <0.05%
Gain Drift: < 3ppm/°C
Wide Supply Range: Single 2.7V to Split
±18V
Micropower Operation: 100µA Supply
Input Offset Voltage: 50µV (Max)
Gain Bandwidth Product: 560kHz
Rail-to-Rail Output
Space Saving 10-Lead MSOP and DFN Packages
The LT
®
1996 combines a precision operational amplifier
with eight precision resistors to form a one-chip solution
for accurately amplifying voltages. Gains from –117 to
118 with a gain accuracy of 0.05% can be achieved without
any external components. The device is particularly well
suited for use as a difference amplifier, where the excellent
resistor matching results in a common mode rejection
ratio of greater than 80dB.
The amplifier features a 50µV maximum input offset
voltage and a gain bandwidth product of 560kHz. The
device operates from any supply voltage from 2.7V to 36V
and draws only 100µA supply current on a 5V supply. The
output swings to within 40mV of either supply rail.
The internal resistors have excellent matching character-
istics; variation is 0.05% over temperature with a guaran-
teed matching temperature coefficent of less than 3ppm/°C.
The resistors are also extremely stable over voltage,
exhibiting a nonlinearity of less than 10ppm.
The LT1996 is fully specified at 5V and
±15V
supplies and
from –40°C to 85°C. The device is available in space
saving 10-lead MSOP and DFN packages. For an amplifier
with selectable gains from –13 to 14, see the LT1991 data
sheet.
APPLICATIO S
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■
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Handheld Instrumentation
Medical Instrumentation
Strain Gauge Amplifiers
Differential to Single-Ended Conversion
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Patents Pending.
TYPICAL APPLICATIO
Rail-to-Rail Gain = 9 Difference Amplifier
15V
450k/81
450k/27
V
M(IN)
∆V
IN
V
P(IN)
INPUT RANGE
±60V
R
IN
= 100kΩ
4pF
450k
V
OUT
= V
REF
+ 9 •
∆V
IN
SWING 40mV TO
EITHER RAIL
PERCENTAGE OF UNITS (%)
–
+
450k/9
–
450k/9
450k/27
450k/81
4pF
V
REF
–15V
1996 TA01
+
LT1996
450k
U
Distribution of Resistor Matching
40
35
30
25
20
15
10
5
0
–0.04
0
–0.02
0.02
RESISTOR MATCHING (%)
0.04
1996 TA01b
U
U
LT1996A
G = 81
1996f
1
LT1996
ABSOLUTE
AXI U RATI GS
Total Supply Voltage (V
+
to V
–
) ............................... 40V
Input Voltage (Pins P9/M9, Note 2) .......................
±60V
Input Current
(Pins P27/M27/P81/M81, Note 2) ..................
±10mA
Output Short-Circuit Duration (Note 3) ............ Indefinite
Operating Temperature Range (Note 4) ...–40°C to 85°C
Specified Temperature Range (Note 5) ....–40°C to 85°C
PACKAGE/ORDER I FOR ATIO
TOP VIEW
P9
P27
P81
V
EE
REF
1
2
3
4
5
10 M9
9 M27
8 M81
7 V
CC
6 OUT
ORDER PART
NUMBER
LT1996CDD
LT1996IDD
LT1996ACDD
LT1996AIDD
DD PART MARKING*
LBPC
TOP VIEW
P9
P27
P81
V
EE
REF
1
2
3
4
5
10
9
8
7
6
M9
M27
M81
V
CC
OUT
DD PACKAGE
10-LEAD (3mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 160°C/W
UNDERSIDE METAL CONNECTED TO V
EE
(PCB CONNECTION OPTIONAL)
*Temperature and electrical grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL
∆G
PARAMETER
Gain Error
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. Difference amplifier configuration, V
S
= 5V, 0V or
±15V;
V
CM
= V
REF
= half supply, unless otherwise noted.
CONDITIONS
V
S
=
±15V,
V
OUT
=
±10V;
R
L
= 10k
G = 81; LT1996AMS
G = 27; LT1996AMS
G = 9; LT1996AMS
G = 81; LT1996ADD
G = 27; LT1996ADD
G = 9; LT1996ADD
G = 81; LT1996
G = 27; LT1996
G = 9; LT1996
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
GNL
∆G/∆T
CMRR
Gain Nonlinearity
Gain Drift vs Temperature (Note 6)
Common Mode Rejection Ratio,
Referred to Inputs (RTI)
V
S
=
±15V;
V
OUT
=
±10V;
R
L
= 10k; G = 9
V
S
=
±15V;
V
OUT
=
±10V;
R
L
= 10k
V
S
=
±15V;
G = 9; V
CM
=
±15.3V
LT1996AMS
LT1996ADD
LT1996
V
S
=
±15V;
G = 27; V
CM
= –14.5V to 14.3V
LT1996AMS
LT1996ADD
LT1996
2
U
U
W
W W
U
W
(Note 1)
Maximum Junction Temperature
DD Package ...................................................... 125°C
MS Package ..................................................... 150°C
Storage Temperature Range
DD Package .......................................–65°C to 125°C
MS Package ......................................–65°C to 150°C
MSOP–Lead Temperature (Soldering, 10 sec)...... 300°C
ORDER PART
NUMBER
LT1996CMS
LT1996IMS
LT1996ACMS
LT1996AIMS
MS PART MARKING*
LTBPB
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 230°C/W
MIN
TYP
±0.02
±0.03
±0.03
±0.02
±0.02
±0.03
±0.04
±0.04
±0.04
1
0.3
MAX
±0.05
±0.06
±0.07
±0.05
±0.07
±0.08
±0.12
±0.12
±0.12
10
3
UNITS
%
%
%
%
%
%
%
%
%
ppm
ppm/°C
dB
dB
dB
dB
dB
dB
1996f
80
80
70
95
90
75
100
100
100
105
105
105
LT1996
ELECTRICAL CHARACTERISTICS
SYMBOL
CMRR
PARAMETER
Common Mode Rejection Ratio (RTI)
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. Difference amplifier configuration, V
S
= 5V, 0V or
±15V;
V
CM
= V
REF
= half supply, unless otherwise noted.
CONDITIONS
V
S
=
±15V;
G = 81; V
CM
= –14.1V to 13.9V
LT1996AMS
LT1996ADD
LT1996
P9/M9 Inputs
V
S
=
±15V;
V
REF
= 0V
V
S
= 5V, 0V; V
REF
= 2.5V
V
S
= 3V, 0V; V
REF
= 1.25V
P9/M9 Inputs, P81/M81 Connected to REF
V
S
=
±15V;
V
REF
= 0V
V
S
= 5V, 0V; V
REF
= 2.5V
V
S
= 3V, 0V; V
REF
= 1.25V
P27/M27 Inputs
V
S
=
±15V;
V
REF
= 0V
V
S
= 5V, 0V; V
REF
= 2.5V
V
S
= 3V, 0V; V
REF
= 1.25V
P81/M81 Inputs
V
S
=
±15V;
V
REF
= 0V
V
S
= 5V, 0V; V
REF
= 2.5V
V
S
= 3V, 0V; V
REF
= 1.25V
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
105
100
85
–15.5
0.84
0.98
–60
–12.6
–1.25
–14.5
0.95
1
–14.1
0.99
1
TYP
120
120
120
MAX
UNITS
dB
dB
dB
V
CM
Input Voltage Range (Note 7)
15.3
3.94
1.86
60
15.6
6.8
14.3
3.84
1.82
13.9
3.81
1.8
15
15
50
135
80
160
100
200
150
250
1
5
7.5
500
750
1000
1500
V
V
V
V
V
V
V
V
V
V
V
V
µV
µV
µV
µV
µV
µV
µV
µV
µV/°C
nA
nA
pA
pA
pA
pA
µV
P-P
µV
RMS
µV
P-P
µV
RMS
nV/√Hz
nV/√Hz
V
OS
Op Amp Offset Voltage (Note 8)
LT1996AMS, V
S
= 5V, 0V
LT1996AMS, V
S
=
±15V
●
LT1996MS
●
25
25
●
●
●
LT1996DD
∆V
OS
/∆T
I
B
I
OS
Op Amp Offset Voltage Drift (Note 6)
Op Amp Input Bias Current
Op Amp Input Offset Current
LT1996A
●
0.3
2.5
50
50
LT1996
●
Op Amp Input Noise Voltage
0.01Hz to 1Hz
0.01Hz to 1Hz
0.1Hz to 10Hz
0.1Hz to 10Hz
G = 9; f = 1kHz
G = 117; f = 1kHz
P9 (M9 = Ground)
P27 (M27 = Ground)
P81 (M81 = Ground)
M9 (P9 = Ground)
M27 (P27 = Ground)
M81 (P81 = Ground)
●
●
●
●
●
●
0.35
0.07
0.25
0.05
46
18
350
326.9
319.2
35
11.69
3.85
500
467
456
50
16.7
5.5
650
607.1
592.8
65
21.71
7.15
e
n
R
IN
Input Noise Voltage Density
(Includes Resistor Noise)
Input Impedance (Note 10)
kΩ
kΩ
kΩ
kΩ
kΩ
kΩ
1996f
3
LT1996
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. Difference amplifier configuration, V
S
= 5V, 0V or
±15V;
V
CM
= V
REF
= half supply, unless otherwise noted.
SYMBOL
∆R
PARAMETER
Resistor Matching (Note 9)
CONDITIONS
G = 81; LT1996AMS
G = 27; LT1996AMS
G = 9; LT1996AMS
G = 81; LT1996ADD
G = 27; LT1996ADD
G = 9; LT1996ADD
G = 81; LT1996
G = 27; LT1996
G = 9; LT1996
∆R/∆T
PSRR
V
OUT
Resistor Temperature Coefficient (Note 6)
Power Supply Rejection Ratio
Minimum Supply Voltage
Output Voltage Swing (to Either Rail)
No Load
V
S
= 5V, 0V
V
S
= 5V, 0V
V
S
=
±15V
1mA Load
V
S
= 5V, 0V
V
S
= 5V, 0V
V
S
=
±15V
I
SC
Output Short-Circuit Current (Sourcing)
Output Short-Circuit Current (Sinking)
BW
–3dB Bandwidth
Drive Output Positive;
Short Output to Ground
Drive Output Negative;
Short Output to V
S
or Midsupply
G=9
G = 27
G = 81
f = 10kHz
G = 9; 0.1V Step; 10% to 90%
G = 81; 0.1V Step; 10% to 90%
G = 9; V
S
= 5V, 0V; 2V Step
G = 9; V
S
= 5V, 0V; –2V Step
G = 9; V
S
=
±15V;
10V Step
G = 9; V
S
=
±15V;
–10V Step
V
S
= 5V, 0V; V
OUT
= 1V to 4V
V
S
=
±15V;
V
OUT
=
±10V
V
S
= 5V, 0V
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
MIN
TYP
±0.02
±0.03
±0.03
±0.02
±0.02
±0.03
±0.04
±0.04
±0.04
0.3
–30
MAX
±0.05
±0.06
±0.07
±0.05
±0.07
±0.08
±0.12
±0.12
±0.12
3
UNITS
%
%
%
%
%
%
%
%
%
ppm/°C
ppm/°C
dB
V
mV
mV
mV
mV
mV
mV
mA
mA
mA
mA
kHz
kHz
kHz
kHz
µs
µs
µs
µs
µs
µs
V/µs
V/µs
Resistor Matching
Absolute Value
V
S
=
±1.35V
to
±18V
(Note 8)
105
135
2.4
40
2.7
55
65
110
225
275
300
●
●
150
●
●
●
●
8
4
8
4
12
21
38
17
7
560
8
40
85
85
110
110
GBWP
t
r
, t
f
t
S
Op Amp Gain Bandwidth Product
Rise Time, Fall Time
Settling Time to 0.01%
SR
I
S
Slew Rate
Supply Current
0.06
0.08
0.12
0.12
100
130
110
150
160
210
µA
µA
µA
µA
V
S
=
±15V
●
Note 1:
Absolute Maximum Ratings are those beyond which the life of the
device may be impaired.
Note 2:
The P27/M27 and P81/M81 inputs are protected by ESD diodes to
the supply rails. If one of these four inputs goes outside the rails, the input
current should be limited to less than 10mA. The P9/M9 inputs can
withstand
±60V
if P81/M81 are grounded and V
S
=
±15V
(see Applications
Information section about “High Voltage CM Difference Amplifiers”).
Note 3:
A heat sink may be required to keep the junction temperature
below absolute maximum ratings.
1996f
4
LT1996
ELECTRICAL CHARACTERISTICS
Note 4:
Both the LT1996C and LT1996I are guaranteed functional over the
–40°C to 85°C temperature range.
Note 5:
The LT1996C is guaranteed to meet the specified performance
from 0°C to 70°C and is designed, characterized and expected to meet
specified performance from –40°C to 85°C but is not tested or QA
sampled at these temperatures. The LT1996I is guaranteed to meet
specified performance from –40°C to 85°C.
Note 6:
This parameter is not 100% tested.
Note 7:
Input voltage range is guaranteed by the CMRR test at V
S
=
±15V.
For the other voltages, this parameter is guaranteed by design and through
correlation with the
±15V
test. See the Applications Information section to
determine the valid input voltage range under various operating
conditions.
Note 8:
Offset voltage, offset voltage drift and PSRR are defined as
referred to the internal op amp. You can calculate output offset as follows.
In the case of balanced source resistance, V
OS, OUT
= V
OS
• Noise Gain +
I
OS
• 450k + I
B
• 450k • (1 – R
P
/R
N
) where R
P
and R
N
are the total
resistance at the op amp positive and negative terminal respectively.
Note 9:
Resistors connected to the minus inputs. Resistor matching is not
tested directly, but is guaranteed by the gain error test.
Note 10:
Input impedance is tested by a combination of direct
measurements and correlation to the CMRR and gain error tests.
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
200
175
SUPPLY CURRENT (µA)
150
125
100
75
50
25
0
0
2
4
6 8 10 12 14 16 18 20
SUPPLY VOLTAGE (±V)
1996 G01
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
OUTPUT VOLTAGE SWING (mV)
OUTPUT VOLTAGE (mV)
Output Voltage Swing vs Load
Current (Output High)
V
CC
–100
OUTPUT VOLTAGE SWING (mV)
OUTPUT SHORT-CIRCUIT CURRENT (mA)
V
S
= 5V, 0V
–200
–300
–400
–500
–600
–700
–800
–900
–1000
0
1
2
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
20
INPUT OFFSET VOLTAGE (µV)
3 4 5 6 7
LOAD CURRENT (mA)
U W
8
9
10
1996 G04
(Difference Amplifier Configuration)
Output Voltage Swing vs Load
Current (Output Low)
V
CC
–20
Output Voltage Swing vs
Temperature
V
S
= 5V, 0V
NO LOAD
OUTPUT HIGH
(RIGHT AXIS)
1400
1200
1000
800
V
S
= 5V, 0V
T
A
= 85°C
–40
–60
T
A
= 25°C
600
T
A
= –40°C
400
200
V
EE
60
40
20
OUTPUT LOW
(LEFT AXIS)
V
EE
–50 –25
0
25
50
75
100
125
0
1
2
TEMPERATURE (°C)
1996 G02
3 4 5 6 7
LOAD CURRENT (mA)
8
9
10
1996 G03
Output Short-Circuit Current vs
Temperature
25
Input Offset Voltage vs
Difference Gain
150
V
S
= 5V, 0V
REPRESENTATIVE PARTS
V
S
= 5V, 0V
SINKING
100
50
0
–50
–100
–150
15
10
SOURCING
5
0
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
1996 G05
9 18 27 36 45 54 63 72 81 90 99 108 117
GAIN (V/V)
1996 G06
1996f
5
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