LBPC [Linear]
Precision, 100uA Gain Selectable Amplifier; 精密， 100uA的可选增益放大器
| 型号： | LBPC |
| 厂家： | 
Linear |
| 描述： | Precision, 100uA Gain Selectable Amplifier |
| 文件： | 总24页 (文件大小：341K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT1996
Precision, 100µA
Gain Selectable Amplifier
U
FEATURES
DESCRIPTIO
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
118withagainaccuracyof0.05%canbeachievedwithout
any external components. The device is particularly well
suitedforuseasadifferenceamplifier, wheretheexcellent
resistor matching results in a common mode rejection
ratio of greater than 80dB.
■
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
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.
■
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)
■
The internal resistors have excellent matching character-
istics; variation is 0.05% over temperature with a guaran-
teedmatchingtemperaturecoefficentoflessthan3ppm/°C.
The resistors are also extremely stable over voltage,
exhibiting a nonlinearity of less than 10ppm.
Gain Bandwidth Product: 560kHz
■
Rail-to-Rail Output
■
Space Saving 10-Lead MSOP and DFN Packages
U
APPLICATIO S
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.
■
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.
U
TYPICAL APPLICATIO
Rail-to-Rail Gain = 9 Difference Amplifier
Distribution of Resistor Matching
V
= V
+ 9 • ∆V
OUT
REF IN
40
35
30
25
20
15
10
5
15V
LT1996A
G = 81
SWING 40mV TO
EITHER RAIL
450k/81
450k/27
450k
4pF
450k/9
–
+
V
M(IN)
–
+
∆V
IN
450k/9
V
P(IN)
LT1996
450k
450k/27
INPUT RANGE
±60V
450k/81
R
= 100kΩ
4pF
IN
0
0
–0.04
–0.02
0.02
0.04
V
REF
RESISTOR MATCHING (%)
1996 TA01
–15V
1996 TA01b
1996f
1
LT1996
W W U W
ABSOLUTE AXI U RATI GS (Note 1)
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
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
U
W
U
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
ORDER PART
NUMBER
TOP VIEW
P9
P27
P81
1
2
3
4
5
10 M9
TOP VIEW
9
8
7
6
M27
M81
LT1996CDD
LT1996IDD
LT1996ACDD
LT1996AIDD
LT1996CMS
P9
P27
P81
EE
REF
1
2
3
4
5
10 M9
9
8
7
6
M27
M81
CC
OUT
LT1996IMS
V
EE
V
CC
V
V
LT1996ACMS
LT1996AIMS
REF
OUT
MS PACKAGE
10-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 230°C/W
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
DD PART MARKING*
LBPC
MS PART MARKING*
LTBPB
TJMAX = 125°C, θJA = 160°C/W
UNDERSIDE METAL CONNECTED TO VEE
(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
VCM = VREF = half supply, unless otherwise noted.
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Difference amplifier configuration, VS = 5V, 0V or ±15V;
SYMBOL
PARAMETER
CONDITIONS
V = ±15V, V
MIN
TYP
MAX
UNITS
∆G
Gain Error
= ±10V; R = 10k
OUT L
S
G = 81; LT1996AMS
G = 27; LT1996AMS
G = 9; LT1996AMS
●
●
●
±0.02
±0.03
±0.03
±0.05
±0.06
±0.07
%
%
%
G = 81; LT1996ADD
G = 27; LT1996ADD
G = 9; LT1996ADD
●
●
●
±0.02
±0.02
±0.03
±0.05
±0.07
±0.08
%
%
%
G = 81; LT1996
G = 27; LT1996
G = 9; LT1996
●
●
●
±0.04
±0.04
±0.04
±0.12
±0.12
±0.12
%
%
%
GNL
Gain Nonlinearity
V = ±15V; V
= ±10V; R = 10k; G = 9
●
●
1
10
3
ppm
S
OUT
OUT
L
∆G/∆T
CMRR
Gain Drift vs Temperature (Note 6)
V = ±15V; V
S
= ±10V; R = 10k
0.3
ppm/°C
L
Common Mode Rejection Ratio,
Referred to Inputs (RTI)
V = ±15V; G = 9; V = ±15.3V
S
CM
LT1996AMS
LT1996ADD
LT1996
●
●
●
80
80
70
100
100
100
dB
dB
dB
V = ±15V; G = 27; V = –14.5V to 14.3V
LT1996AMS
LT1996ADD
LT1996
S
CM
●
●
●
95
90
75
105
105
105
dB
dB
dB
1996f
2
LT1996
The ● denotes the specifications which apply over the full operating
ELECTRICAL CHARACTERISTICS
VCM = VREF = half supply, unless otherwise noted.
temperature range, otherwise specifications are at TA = 25°C. Difference amplifier configuration, VS = 5V, 0V or ±15V;
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
CMRR
Common Mode Rejection Ratio (RTI)
V = ±15V; G = 81; V = –14.1V to 13.9V
LT1996AMS
LT1996ADD
LT1996
S
CM
●
●
●
105
100
85
120
120
120
dB
dB
dB
V
Input Voltage Range (Note 7)
P9/M9 Inputs
CM
V = ±15V; V = 0V
●
●
●
–15.5
0.84
0.98
15.3
3.94
1.86
V
V
V
S
REF
V = 5V, 0V; V = 2.5V
S
REF
V = 3V, 0V; V = 1.25V
S
REF
P9/M9 Inputs, P81/M81 Connected to REF
V = ±15V; V = 0V
●
●
●
–60
–12.6
–1.25
60
15.6
6.8
V
V
V
S
REF
V = 5V, 0V; V = 2.5V
S
REF
V = 3V, 0V; V = 1.25V
S
REF
P27/M27 Inputs
V = ±15V; V = 0V
●
●
●
–14.5
0.95
1
14.3
3.84
1.82
V
V
V
S
REF
V = 5V, 0V; V = 2.5V
S
REF
V = 3V, 0V; V = 1.25V
S
REF
P81/M81 Inputs
V = ±15V; V = 0V
●
●
●
–14.1
0.99
1
13.9
3.81
1.8
V
V
V
S
REF
V = 5V, 0V; V = 2.5V
S
REF
V = 3V, 0V; V = 1.25V
S
REF
V
Op Amp Offset Voltage (Note 8)
LT1996AMS, V = 5V, 0V
15
15
25
25
50
135
µV
µV
OS
S
●
●
●
LT1996AMS, V = ±15V
80
160
µV
µV
S
LT1996MS
LT1996DD
100
200
µV
µV
150
250
µV
µV
●
●
∆V /∆T
Op Amp Offset Voltage Drift (Note 6)
Op Amp Input Bias Current
0.3
2.5
1
µV/°C
OS
I
5
7.5
nA
nA
B
●
●
●
I
Op Amp Input Offset Current
LT1996A
LT1996
50
50
500
750
pA
pA
OS
1000
1500
pA
pA
Op Amp Input Noise Voltage
0.01Hz to 1Hz
0.01Hz to 1Hz
0.1Hz to 10Hz
0.1Hz to 10Hz
0.35
0.07
0.25
0.05
µV
P-P
µV
RMS
µV
P-P
µV
RMS
e
Input Noise Voltage Density
(Includes Resistor Noise)
G = 9; f = 1kHz
G = 117; f = 1kHz
46
18
nV/√Hz
nV/√Hz
n
R
IN
Input Impedance (Note 10)
P9 (M9 = Ground)
P27 (M27 = Ground)
P81 (M81 = Ground)
●
●
●
350
326.9
319.2
500
467
456
650
607.1
592.8
kΩ
kΩ
kΩ
M9 (P9 = Ground)
M27 (P27 = Ground)
M81 (P81 = Ground)
●
●
●
35
11.69
3.85
50
16.7
5.5
65
21.71
7.15
kΩ
kΩ
kΩ
1996f
3
LT1996
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Difference amplifier configuration, VS = 5V, 0V or ±15V;
VCM = VREF = half supply, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
∆R
Resistor Matching (Note 9)
G = 81; LT1996AMS
G = 27; LT1996AMS
G = 9; LT1996AMS
●
●
●
±0.02
±0.03
±0.03
±0.05
±0.06
±0.07
%
%
%
G = 81; LT1996ADD
G = 27; LT1996ADD
G = 9; LT1996ADD
●
●
●
±0.02
±0.02
±0.03
±0.05
±0.07
±0.08
%
%
%
G = 81; LT1996
G = 27; LT1996
G = 9; LT1996
●
●
●
±0.04
±0.04
±0.04
±0.12
±0.12
±0.12
%
%
%
∆R/∆T
Resistor Temperature Coefficient (Note 6) Resistor Matching
Absolute Value
●
●
0.3
–30
3
ppm/°C
ppm/°C
PSRR
Power Supply Rejection Ratio
Minimum Supply Voltage
V = ±1.35V to ±18V (Note 8)
S
●
●
105
135
2.4
dB
V
2.7
V
Output Voltage Swing (to Either Rail)
No Load
OUT
V = 5V, 0V
40
55
65
110
mV
mV
mV
S
V = 5V, 0V
●
●
S
V = ±15V
S
1mA Load
V = 5V, 0V
150
225
275
300
mV
mV
mV
S
V = 5V, 0V
●
●
S
V = ±15V
S
I
Output Short-Circuit Current (Sourcing)
Output Short-Circuit Current (Sinking)
–3dB Bandwidth
Drive Output Positive;
Short Output to Ground
8
4
12
21
mA
mA
SC
●
●
Drive Output Negative;
8
4
mA
mA
Short Output to V or Midsupply
S
BW
G = 9
G = 27
G = 81
38
17
7
kHz
kHz
kHz
GBWP
Op Amp Gain Bandwidth Product
Rise Time, Fall Time
f = 10kHz
560
kHz
t , t
G = 9; 0.1V Step; 10% to 90%
G = 81; 0.1V Step; 10% to 90%
8
40
µs
µs
r
f
t
Settling Time to 0.01%
G = 9; V = 5V, 0V; 2V Step
85
85
110
110
µs
µs
µs
µs
S
S
G = 9; V = 5V, 0V; –2V Step
S
G = 9; V = ±15V; 10V Step
S
G = 9; V = ±15V; –10V Step
S
SR
Slew Rate
V = 5V, 0V; V = 1V to 4V
●
●
0.06
0.08
0.12
0.12
V/µs
V/µs
S
OUT
V = ±15V; V = ±10V
S
OUT
I
Supply Current
V = 5V, 0V
100
110
150
µA
µA
S
S
●
●
V = ±15V
S
130
160
210
µA
µA
Note 1: Absolute Maximum Ratings are those beyond which the life of the
device may be impaired.
withstand ±60V if P81/M81 are grounded and V = ±15V (see Applications
Information section about “High Voltage CM Difference Amplifiers”).
S
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
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.
determine the valid input voltage range under various operating
conditions.
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 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
= V • Noise Gain +
OS, OUT
OS
I
• 450k + I • 450k • (1 – R /R ) where R and R are the total
OS
B P N P N
resistance at the op amp positive and negative terminal respectively.
Note 6: This parameter is not 100% tested.
Note 7: Input voltage range is guaranteed by the CMRR test at V = ±15V.
Note 9: Resistors connected to the minus inputs. Resistor matching is not
tested directly, but is guaranteed by the gain error test.
S
For the other voltages, this parameter is guaranteed by design and through
correlation with the ±15V test. See the Applications Information section to
Note 10: Input impedance is tested by a combination of direct
measurements and correlation to the CMRR and gain error tests.
U W
TYPICAL PERFOR A CE CHARACTERISTICS (Difference Amplifier Configuration)
Output Voltage Swing vs
Temperature
Output Voltage Swing vs Load
Current (Output Low)
Supply Current vs Supply Voltage
200
175
150
125
100
75
V
CC
1400
1200
1000
800
V
= 5V, 0V
V
= 5V, 0V
S
S
NO LOAD
–20
–40
–60
T
= 85°C
OUTPUT HIGH
(RIGHT AXIS)
A
T
= 85°C
A
T
= 25°C
A
T
= –40°C
A
T
= 25°C
A
600
60
40
20
T
= –40°C
A
400
50
OUTPUT LOW
(LEFT AXIS)
200
25
0
V
EE
V
EE
0
2
4
6
8
10 12 14 16 18 20
–25
0
25
50
75
125
–50
100
0
3
4
5
6
7
8
9
10
1
2
SUPPLY VOLTAGE (±V)
TEMPERATURE (°C)
LOAD CURRENT (mA)
1996 G01
1996 G02
1996 G03
Output Voltage Swing vs Load
Current (Output High)
Output Short-Circuit Current vs
Temperature
Input Offset Voltage vs
Difference Gain
150
100
50
V
25
20
15
10
5
CC
V
S
= 5V, 0V
V
S
= 5V, 0V
V
= 5V, 0V
S
REPRESENTATIVE PARTS
–100
–200
–300
–400
–500
–600
–700
–800
–900
–1000
SINKING
T
A
= –40°C
T
A
= 85°C
T
A
= 25°C
0
SOURCING
–50
–100
–150
0
4
0
1
2
3
5
6
7
8
9
10
9
18 27 36 45 54 63 72 81 90 99 108 117
–50
0
25
50
75 100 125
–25
LOAD CURRENT (mA)
GAIN (V/V)
1996 G06
1996 G04
TEMPERATURE (°C)
1996 G05
1996f
5
LT1996
U W
TYPICAL PERFOR A CE CHARACTERISTICS (Difference Amplifier Configuration)
Output Offset Voltage vs
Difference Gain
Gain Error vs Load Current
Slew Rate vs Temperature
10.0
7.5
0.30
0.25
0.20
0.15
0.10
0.05
0
0.04
0.03
0.02
0.01
0
V
= 5V, 0V
GAIN = 9
GAIN = 81
S
REPRESENTATIVE PARTS
V
V
= ±15V
V
V
A
= ±15V
S
OUT
S
OUT
= ±10V
= ±10V
T
= 25°C
5.0
2.5
–
SR (FALLING EDGE)
0
+
SR (RISING EDGE)
–2.5
–5.0
–7.5
–10.0
–0.01
–0.02
–0.03
–0.04
REPRESENTATIVE UNITS
9
18 27 36 45 54 63 72 81 90 99 108 117
GAIN (V/V)
50
0
TEMPERATURE (°C)
100 125
–50 –25
25
75
1
2
4
3
LOAD CURRENT (mA)
0
5
1996 G07
1996 G09
1996 G08
Bandwidth vs Gain
CMRR vs Frequency
PSRR vs Frequency
40
35
30
25
20
15
10
5
120
110
100
90
80
70
60
50
40
30
20
10
0
130
120
110
100
90
80
70
60
50
40
30
20
10
V
T
= 5V, 0V
V
T
= 5V, 0V
V
T
= 5V, 0V
S
A
S
A
S
A
= 25°C
= 25°C
GAIN = 81
= 25°C
GAIN = 27
GAIN = 9
GAIN = 81
GAIN = 9
GAIN = 27
10k
0
0
10
100
1k
100k
9
18 27 36 45 54 63 72 81 90 99 108 117
GAIN (V/V)
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
1996 G12
1996 G11
1996 G10
Output Impedance vs Frequency
CMRR vs Temperature
Gain Error vs Temperature
120
100
80
60
40
20
0
1000
100
10
0.030
0.025
0.020
0.015
0.010
0.005
0
V
T
= 5V, 0V
GAIN = 9
S
GAIN = 9
S
S
A
= 25°C
V = ±15V
V
= ±15V
GAIN = 81
GAIN = 27
GAIN = 9
1
0.1
0.01
REPRESENTATIVE UNITS
REPRESENTATIVE UNITS
50
TEMPERATURE (°C)
100 125
–50 –25
0
25
75
50
TEMPERATURE (°C)
100 125
–50 –25
0
25
75
1
10
100
1k
10k
100k
FREQUENCY (Hz)
1996 G13
1996 G14
1996 G15
1996f
6
LT1996
U W
TYPICAL PERFOR A CE CHARACTERISTICS (Difference Amplifier Configuration)
Gain vs Frequency
Gain and Phase vs Frequency
0.01Hz to 1Hz Voltage Noise
40
30
20
10
0
50
40
30
20
10
0
0
V
A
= 5V, 0V
V
= 5V, 0V
S
S
PHASE
(RIGHT AXIS)
V
= ±15V
= 25°C
S
A
–20
T
= 25°C
T
= 25°C
A
T
GAIN = 9
MEASURED IN G =117
–40
GAIN = 81
GAIN = 27
GAIN = 9
REFERRED TO OP AMP INPUTS
–60
–80
GAIN
(LEFT AXIS)
–100
–120
–140
–160
–180
–200
–10
0.5
1
10
100
500
0.1
1
10
100
400
0
10 20 30 40 50 60 70 80 90 100
FREQUENCY (kHz)
FREQUENCY (kHz)
TIME (s)
1996 G16
1996 G17
1996 G21
Small Signal Transient Response,
Gain = 9
Small Signal Transient Response,
Gain = 27
Small Signal Transient Response,
Gain = 81
50mV/DIV
50mV/DIV
50mV/DIV
1996 G18
1996 G20
1996 G19
10µs/DIV
50µs/DIV
20µs/DIV
U
U
U
(Difference Amplifier Configuration)
PI FU CTIO S
resistor to the op amp’s noninverting input.
P9 (Pin 1): Noninverting Gain-of-9 input. Connects a 50k
internal resistor to the op amp’s noninverting input.
OUT (Pin 6): Output. VOUT = VREF + 9 • (VP1 – VM1) + 27 •
(VP3 – VM3) + 81 • (VP9 – VM9).
P27 (Pin 2): Noninverting Gain-of-27 input. Connects a
(50k/3)internalresistortotheopamp’snoninvertinginput.
VCC (Pin 7): Positive Power Supply. Can be anything from
2.7V to 36V above the VEE voltage.
P81 (Pin 3): Noninverting Gain-of-81 input. Connects a
(50k/9)internalresistortotheopamp’snoninvertinginput.
M81 (Pin 8): Inverting Gain-of-81 input. Connects a
(50k/9) internal resistor to the op amp’s inverting input.
VEE (Pin 4): Negative Power Supply. Can be either ground
(in single supply applications), or a negative voltage (in
split supply applications).
M27 (Pin 9): Inverting Gain-of-27 input. Connects a
(50k/3) internal resistor to the op amp’s inverting input.
REF (Pin 5): Reference Input. Sets the output level when
differencebetweeninputsiszero. Connectsa450kinternal
M9 (Pin 10): Inverting Gain-of-9 input. Connects a 50k
internal resistor to the op amp’s inverting input.
1996f
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BLOCK DIAGRA
10
9
8
7
6
M9
M27
M81
V
CC
OUT
450k/81
450k
4pF
450k/27
450k/9
450k/9
–
+
OUT
LT1996
450k/27
4pF
450k
450k/81
P9
P27
P81
V
EE
REF
1996 BD
1
2
3
4
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APPLICATIO S I FOR ATIO
Introduction
of VEE. For many configurations though, the chip inputs
will function rail-to-rail because of effective attenuation to
the +input. The output is truly rail-to-rail, getting to within
40mV of the supply rails. The gain bandwidth product of
the op amp is about 560kHz. In noise gains of 2 or more,
itisstableintocapacitiveloadsupto500pF. Innoisegains
below 2, it is stable into capacitive loads up to 100pF.
TheLT1996maybethelastopampyoueverhavetostock.
Because it provides you with several precision matched
resistors, you can easily configure it into several different
classical gain circuits without adding external compo-
nents. The several pages of simple circuits in this data
sheet demonstrate just how easy the LT1996 is to use. It
canbeconfiguredintodifferenceamplifiers,aswellasinto
inverting and noninverting single ended amplifiers. The
fact that the resistors and op amp are provided together in
such a small package will often save you board space and
reduce complexity for easy probing.
The Resistors
The resistors internal to the LT1996 are very well matched
SiChrome based elements protected with barrier metal.
Although their absolute tolerance is fairly poor (±30%),
their matching is to within 0.05%. This allows the chip to
achieve a CMRR of 80dB, and gain errors within 0.05%.
The resistor values are (450k/9), (450k/27), (450k/81)
and 450k, connected to each of the inputs. The resistors
havepowerlimitationsof1wattforthe450kand(450k/81)
resistors, 0.3watt for the (450k/27) resistors and 0.5watt
for the (450k/9) resistors; however, in practice, power
dissipation will be limited well below these values by the
The Op Amp
The op amp internal to the LT1996 is a precision device
with 15µV typical offset voltage and 3nA input bias cur-
rent. The input offset current is extremely low, so match-
ing the source resistance seen by the op amp inputs will
provide for the best output accuracy. The op amp inputs
are not rail-to-rail, but extend to within 1.2V of VCC and 1V
1996f
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maximum voltage allowed on the input and REF pins. The
50k resistors connected to the M9 and P9 inputs are
isolated from the substrate, and can therefore be taken
beyond the supply voltages. The naming of the pins “P9,”
“P27,” “P81,” etc., is based on their admittances relative
to the feedback and REF admittances. Because it has 9
times the admittance, the voltage applied to the P9 input
has 9 times the effect of the voltage applied to the REF
input.
classical noninverting op amp configuration, the LT1996
presents the high input impedance of the op amp, as is
usual for the noninverting case.
Common Mode Input Voltage Range
The LT1996 valid common mode input range is limited by
three factors:
1. Maximum allowed voltage on the pins
2. The input voltage range of the internal op amp
3. Valid output voltage
Bandwidth
The bandwidth of the LT1996 will depend on the gain you
select (or more accurately the noise gain resulting from
the gain you select). In the lowest configurable gain of 1,
the –3dB bandwidth is limited to 450kHz, with peaking of
about 2dB at 280kHz. In the highest configurable gains,
bandwidth is limited to 5kHz.
The maximum voltage allowed on the P27, M27, P81 and
M81 inputs includes the positive and negative supply plus
a diode drop. These pins should not be driven more than
a diode drop outside of the supply rails. This is because
theyareconnectedthroughdiodestointernalmanufactur-
ing post-package trim circuitry, and through a substrate
diode to VEE. If more than 10mA is allowed to flow through
thesepins,thereisariskthattheLT1996willbedetrimmed
or damaged. The P9 and M9 inputs do not have clamp
diodes or substrate diodes or trim circuitry and can be
taken well outside the supply rails. The maximum allowed
voltage on the P9 and M9 pins is ±60V.
Input Noise
TheLT1996inputnoiseiscomprisedoftheJohnsonnoise
of the internal resistors (√4kTR), and the input voltage
noise of the op amp. Paralleling all four resistors to the
+input gives a 3.8kΩ resistance, for 8nV/√Hz of voltage
noise. The equivalent network on the –input gives another
8nV/√Hz, and the op amp 14nV/√Hz. Taking their RMS
sum gives a total 18nV/√Hz input referred noise floor.
Output noise depends on configuration and noise gain.
The input voltage range of the internal op amp extends to
within 1.2V of VCC and 1V of VEE. The voltage at which the
op amp inputs common mode is determined by the
voltage at the op amp’s +input, and this is determined by
the voltages on pins P9, P27, P81 and REF. (See “Calcu-
lating Input Voltage Range” section.) This is true provided
thattheopampisfunctioningandfeedbackismaintaining
the inputs at the same voltage, which brings us to the third
requirement.
Input Resistance
The LT1996 input resistances vary with configuration, but
once configured are apparent on inspection. Note that
resistors connected to the op amp’s –input are looking
intoavirtualground, sotheysimplyparallel. Anyfeedback
resistance around the op amp does not contribute to input
resistance. Resistors connected to the op amp’s +input
are looking into a high impedance, so they add as parallel
or series depending on how they are connected, and
whether or not some of them are grounded. The op amp
+input itself presents a very high GΩ impedance. In the
For valid circuit function, the op amp output must not be
clipped.Theoutputwillclipiftheinputsignalsareattempt-
ing to force it to within 40mV of its supply voltages. This
usually happens due to too large a signal level, but it can
also occur with zero input differential and must therefore
be included as an example of a common mode problem.
1996f
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R
F
Consider Figure 1. This shows the LT1996 configured as
a gain of 117 difference amplifier on a single supply with
V
CC
R
R
G
G
5V
7
–
+
V
EXT
V
INT
450k/81
450k
4pF
8
V
EE
V
450k/27
450k/9
REF
9
R
F
1996 F02
10
–
+
Figure 2. Calculating CM Input Voltage Range
–
6
5
V
DM
0V
V
= 117 • V
DM
OUT
450k/9
450k/27
450k/81
+
1
2
3
These two voltages represent the high and low extremes
of the common mode input range, if the other limits have
notalreadybeenexceeded(1and3,above).Inmostcases,
the inverting inputs M9 through M81 can be taken further
than these two extremes because doing this does not
move the op amp input common mode. To calculate the
limit on this additional range, see Figure 3. Note that, with
V
CM
2.5V
4pF
450k
REF
LT1996
1996 F01
4
Figure 1. Difference Amplifier Cannot Produce 0V on a Single
Supply. Provide a Negative Supply, or Raise Pin 5, or Provide
400µV of VDM
R
F
theoutputREFconnectedtoground. Thisisagreatcircuit,
but it does not support VDM = 0V at any common mode
because the output clips into ground while trying to
produce 0VOUT. It can be fixed simply by declaring the
valid input differential range not to extend below +0.4mV,
or by elevating the REF pin above 40mV, or by providing
a negative supply.
V
CC
R
G
G
V
–
+
MORE
V
INT
V
EXT
MAX OR MIN
R
V
EE
V
REF
R
F
1996 F03
Figure 3. Calculating Additional Voltage Range of
Inverting Inputs
Calculating Input Voltage Range
Figure 2 shows the LT1996 in the generalized case of a
difference amplifier, with the inputs shorted for the com-
mon mode calculation. The values of RF and RG are
dictated by how the P inputs and REF pin are connected.
By superposition we can write:
VMORE = 0, the op amp output is at VREF. From the max
VEXT (the high cm limit), as VMORE goes positive, the op
ampoutputwillgomorenegativefromVREF bytheamount
VMORE • RF/RG, so:
VOUT = VREF – VMORE • RF/RG
Or:
V
INT = VEXT • (RF/(RF + RG)) + VREF • (RG/(RF + RG))
Or, solving for VEXT
:
VMORE = (VREF – VOUT) • RG/RF
The most negative that VOUT can go is VEE + 0.04V, so:
VEXT = VINT • (1 + RG/RF) – VREF • RG/RF
But valid VINT voltages are limited to VCC – 1.2V and VEE +
1V, so:
Max VMORE = (VREF – VEE – 0.04V) • RG/RF
(should be positive)
MAX VEXT = (VCC – 1.2) • (1 + RG/RF) – VREF • RG/RF
and:
Thesituationwherethisfunctionisnegative,andtherefore
problematic, when VREF = 0 and VEE = 0, has already been
dealt with in Figure 1. The strength of the equation is
MIN VEXT = (VEE + 1) • (1 + RG/RF) – VREF • RG/RF
demonstrated in that it provides the three solutions
1996f
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APPLICATIO S I FOR ATIO
suggested in Figure 1: raise VREF, lower VEE, or provide
some negative VMORE
representation of the circuit on the top. The LT1996 is
shown on the bottom configured in a precision gain of 9.1.
One of the benefits of the noninverting op amp configura-
tion is that the input impedance is extremely high. The
LT1996 maintains this benefit. Given the finite number of
available feedback resistors in the LT1996, the number of
gain configurations is also finite. The complete list of such
Hi-Z input noninverting gain configurations is shown in
Table 1. Many of these are also represented in Figure 5 in
schematic form. Note that the P-side resistor inputs have
been connected so as to match the source impedance
seen by the internal op amp inputs. Note also that gain and
noise gain are identical, for optimal precision.
.
Likewise, from the lower common mode extreme, making
the negative input more negative will raise the output
voltage, limited by VCC – 0.04V.
MIN VMORE = (VREF – VCC + 0.04V) • RG/RF
(should be negative)
Again, the additional input range calculated here is only
available provided the other remaining constraint is not
violated, the maximum voltage allowed on the pin.
The Classical Noninverting Amplifier: High Input Z
Table 1. Configuring the M Pins for Simple Noninverting Gains.
The P Inputs are driven as shown in the examples on the next
page
Perhaps the most common op amp configuration is the
noninverting amplifier. Figure 4 shows the textbook
M81, M27, M9 Connection
R
F
Gain
1
M81
Output
M27
M9
Output
Output
R
G
1.08
1.11
1.30
1.32
1.33
1.44
3.19
3.7
Output
Output
Grounded
Grounded
Output
–
+
Output
Float
V
OUT
Output
Grounded
Output
V
IN
V
= GAIN • V
GAIN = 1 + R /R
OUT
IN
G
Float
Grounded
Float
F
Output
Grounded
Grounded
Output
CLASSICAL NONINVERTING OP AMP CONFIGURATION.
YOU PROVIDE THE RESISTORS.
Output
Grounded
Output
Grounded
Float
Grounded
Output
Output
3.89
4.21
9.1
Grounded
Grounded
Grounded
Float
Float
450k/81
450k
4pF
8
Output
Grounded
Output
450k/27
450k/9
9
Float
10
Float
Grounded
Output
10
–
+
11.8
28
Grounded
Float
Grounded
Grounded
Grounded
Float
6
V
OUT
Float
450k/9
450k/27
450k/81
1
2
3
37
Float
Grounded
Float
4pF
82
Grounded
Grounded
Grounded
Grounded
91
Float
Grounded
Float
450k
109
118
Grounded
Grounded
LT1996
5
Grounded
V
IN
CLASSICAL NONINVERTING OP AMP CONFIGURATION
IMPLEMENTED WITH LT1991. R = 45k, R = 5.6k, GAIN = 9.1.
F
G
GAIN IS ACHIEVED BY GROUNDING, FLOATING OR FEEDING BACK
THE AVAILABLE RESISTORS TO ARRIVE AT DESIRED R AND R .
F
G
1996 F04
WE PROVIDE YOU WITH <0.1% RESISTORS.
Figure 4. The LT1996 as a Classical Noninverting Op Amp
1996f
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+
+
7
+
V
S
V
V
S
S
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
V
V
V
CC
CC
CC
6
6
6
6
6
6
6
6
6
LT1996
V
V
V
LT1996
V
V
V
LT1996
V
V
V
OUT
REF
5
OUT
OUT
OUT
OUT
REF
5
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
REF
5
V
P9
P27
P81
P9
P27
P81
P9
P27
P81
IN
V
V
V
EE
EE
EE
V
V
IN
IN
4
4
4
–
V
S
–
–
V
S
V
S
GAIN = 1
GAIN = 10
GAIN = 3.893
+
V
+
+
7
S
V
V
S
S
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
V
V
V
CC
CC
CC
LT1996
LT1996
LT1996
OUT
REF
5
OUT
REF
5
1
2
3
1
2
3
1
2
3
REF
5
P9
P27
P81
P9
P27
P81
P9
P27
P81
V
V
V
EE
EE
EE
4
4
4
–
V
S
–
–
V
V
S
S
V
V
V
IN
IN
IN
GAIN = 28
GAIN = 37
GAIN = 9.1
+
7
+
7
+
V
S
V
V
S
S
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
V
V
V
CC
CC
CC
LT1996
LT1996
LT1996
OUT
REF
5
OUT
REF
5
1
2
3
1
2
3
1
2
3
REF
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
V
V
V
EE
EE
EE
V
V
IN
IN
4
4
4
–
V
S
–
–
V
V
S
S
V
IN
GAIN = 11.8
GAIN = 82
GAIN = 91
+
+
V
S
V
S
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
7
7
V
V
CC
CC
6
6
LT1996
V
LT1996
V
OUT
OUT
OUT
OUT
1
2
3
1
2
3
REF
REF
5
P9
P27
P81
P9
P27
P81
5
V
V
EE
EE
V
IN
4
4
–
V
S
–
V
S
V
IN
1996 F05
GAIN = 109
GAIN = 118
Figure 5. Some Implementations of Classical Noninverting
Gains Using the LT1996. High Input Z Is Maintained
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Table 2. Configuring the P Pins for Various Attenuations. Those
Shown in Bold Are Functional Even When the Input Drive
Exceeds the Supplies
Attenuation Using the P Input Resistors
Attenuation happens as a matter of fact in difference
amplifier configurations, but it is also used for reducing
peak signal level or improving input common mode range
even in single ended systems. When signal conditioning
indicates a need for attenuation, the LT1996 resistors are
ready at hand. The four precision resistors can provide
several attenuation levels, and these are tabulated in
Table 2 as a design reference.
P81, P27, P9, REF Connection
A
P81
Grounded
Grounded
Grounded
Grounded
Float
P27
Grounded
Grounded
Float
P9
REF
Driven
Driven
Driven
Driven
0.0085
0.0092
0.0110
0.0122
0.0270
0.0357
0.0763
0.0769
0.0847
0.0989
0.1
0.110
0.229
0.231
0.237
0.243
0.248
0.25
Grounded
Float
Grounded
Float
Float
Grounded
Grounded
Grounded
Grounded
Grounded
Float
Grounded
Float
Driven
Driven
Driven
Driven
Driven
Driven
Driven
Driven
Float
Grounded
Grounded
Grounded
Grounded
Grounded
Grounded
Grounded
Grounded
Grounded
Float
Grounded
Float
Grounded
Grounded
Float
Grounded
Grounded
Grounded
Driven
Driven
Driven
Float
Driven
Float
Driven
Float
Driven
Driven
Driven
Driven
Float
Driven
Driven
Driven
Driven
Float
Float
Driven
Driven
Driven
Driven
Grounded
Float
Driven
V
IN
Grounded
Float
V
V
INT
450k/9
450k/27
450k/81
IN
1
2
3
Float
Float
R
R
OKAY UP
+
A
TO ±60V
Driven
V
INT
Driven
Driven
Driven
Grounded
Driven
Grounded
Grounded
Grounded
Driven
Float
Grounded
Float
G
V
= A • V
IN
INT
A = R /(R + R )
450k
G
A
G
LT1996
Driven
5
Grounded
Grounded
Float
CLASSICAL ATTENUATOR
LT1991 ATTENUATING TO THE +INPUT BY
DRIVING AND GROUNDING AND FLOATING
Grounded
Driven
Driven
Float
INPUTS R = 50k, R = 50k/9, SO A = 0.1.
A
G
1996 F06
0.25
Float
Driven
Driven
0.257
0.270
0.305
0.308
0.314
0.686
0.692
0.695
0.730
0.743
0.75
0.752
0.757
0.763
0.769
0.771
0.890
0.9
0.901
0.915
0.923
0.924
0.964
0.973
0.988
0.989
0.991
0.992
Driven
Float
Figure 6. LT1996 Provides for Easy Attenuation to the Op Amp’s
+Input. The P9 Input Can Be Taken Well Outside of the Supplies
Grounded
Driven
Driven
Driven
Driven
Driven
Grounded
Float
Because the attenuations and the noninverting gains are
set independently, they can be combined. This provides
high gain resolution, about 700 unique gains between
0.0085 and 118, as plotted in Figure 7. This is too large a
number to tabulate, but the designer can calculate achiev-
able gain by taking the vector product of the gains and
attenuationsinTables1and2,andseekingthebestmatch.
Average gain resolution is 1.5%, with worst case steps of
about 50% as seen in Figure 7.
Driven
Driven
Driven
Grounded
Grounded
Grounded
Driven
Grounded
Driven
Grounded
Driven
Grounded
Grounded
Grounded
Float
Float
Float
Driven
Driven
Driven
Driven
Driven
Float
Grounded
Grounded
Grounded
Grounded
Float
Grounded
Float
Grounded
Driven
Grounded
Float
Driven
Grounded
Grounded
Float
Driven
Driven
Grounded
Float
Driven
Driven
1000
100
10
Driven
Grounded
Driven
Grounded
Grounded
Grounded
Grounded
Float
Driven
Float
Driven
Float
Grounded
Grounded
Driven
Grounded
Float
1
0.1
Driven
0.01
0.001
Grounded
Grounded
Grounded
Grounded
Grounded
Grounded
0
100 200 300 400 500 600 700
COUNT
1996 F07
Float
Driven
Driven
Figure 7. Over 600 Unique Gain Settings Achievable with the
LT1996 by Combining Attenuation with Noninverting Gain
Driven
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Table 3. Configuring the M Pins for Simple Inverting Gains
M81, M27, M9 Connection
Inverting Configuration
The inverting amplifier, shown in Figure 8, is another
classical op amp configuration. The circuit is actually
identical to the noninverting amplifier of Figure 4, except
that VIN and GND have been swapped. The list of available
gains is shown in Table 3, and some of the circuits are
shown in Figure 9. Noise gain is 1+|Gain|, as is the usual
caseforinvertingamplifiers. Again, forthebestDCperfor-
mance, match the source impedance seen by the op amp
inputs.
Gain
–0.083
–0.110
–0.297
–0.321
–0.329
–0.439
–2.19
–2.7
M81
Output
Output
Output
Float
M27
Output
Float
M9
Drive
Drive
Output
Drive
Float
Drive
Output
Drive
Drive
Output
Drive
Output
Output
Float
Output
Output
Drive
Float
Drive
Output
Output
Float
R
F
–2.89
–3.21
–8.1
Drive
Drive
Drive
Float
Drive
Output
Drive
Output
Float
R
G
V
–
+
IN
–9
Float
V
OUT
–10.8
–27
Drive
Float
Drive
Drive
Drive
Float
V
= GAIN • V
IN
OUT
GAIN = – R /R
F
G
–36
Float
Drive
Float
CLASSICAL INVERTING OP AMP CONFIGURATION.
YOU PROVIDE THE RESISTORS.
–81
Drive
Drive
Drive
Drive
–90
Float
Drive
Float
–108
–117
Drive
Drive
450k/81
450k
4pF
Drive
8
9
V
IN
(DRIVE)
450k/27
450k/9
10
–
+
6
V
OUT
450k/9
450k/27
450k/81
1
2
3
4pF
450k
LT1996
5
CLASSICAL INVERTING OP AMP CONFIGURATION IMPLEMENTED
WITH LT1991. R = 45k, R = 5.55k, GAIN = –8.1.
F
G
GAIN IS ACHIEVED BY GROUNDING, FLOATING OR FEEDING BACK
THE AVAILABLE RESISTORS TO ARRIVE AT DESIRED R AND R .
F
G
1996 F08
WE PROVIDE YOU WITH <0.1% RESISTORS.
Figure 8. The LT1996 as a Classical Inverting Op Amp. Note the
Circuit Is Identical to the Noninverting Amplifier, Except that VIN
and Ground Have Been Swapped
1996f
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+
+
+
V
S
V
V
S
S
8
9
10
8
9
10
8
9
10
V
M81
M27
M9
M81
M27
M9
M81
M27
M9
IN
7
7
7
V
V
V
CC
CC
CC
V
V
IN
IN
6
6
6
6
6
6
6
LT1996
V
V
V
LT1996
V
V
V
LT1996
V
OUT
REF
5
OUT
REF
5
OUT
REF
5
OUT
OUT
OUT
OUT
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
V
V
V
EE
EE
EE
4
4
4
–
V
S
–
–
V
S
V
S
GAIN = –0.321
GAIN = –9
GAIN = –2.89
+
V
+
+
7
S
V
V
S
S
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
IN
7
7
V
IN
V
CC
V
CC
V
CC
V
IN
6
LT1996
LT1996
LT1996
V
OUT
REF
5
OUT
REF
5
OUT
REF
5
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
V
V
V
EE
EE
EE
4
4
4
–
–
–
V
S
V
S
V
S
GAIN = –27
GAIN = –36
GAIN = –8.1
+
7
+
7
+
V
S
V
V
S
S
8
9
10
8
9
10
8
9
10
V
V
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
IN
IN
IN
7
V
CC
V
CC
V
CC
6
LT1996
LT1996
LT1996
V
OUT
REF
5
OUT
REF
5
OUT
REF
5
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
V
V
V
EE
EE
EE
4
4
4
–
–
–
V
S
V
V
S
S
GAIN = –10.8
GAIN = –81
GAIN = –90
+
+
V
S
V
S
8
9
10
8
9
10
V
M81
M27
M9
M81
M27
M9
IN
7
7
V
V
CC
CC
V
IN
6
6
LT1996
V
LT1996
V
OUT
OUT
REF
OUT
OUT
1
2
3
1
2
3
REF
5
P9
P27
P81
P9
P27
P81
5
V
V
EE
EE
4
4
–
–
V
S
V
S
1996 F09
GAIN = –108
GAIN = –117
Figure 9. It Is Simple to Get Precision Inverting Gains with the LT1996.
Input Impedance Varies from 3.8kΩ (Gain = –117) to 50kΩ (Gain = –9)
1996f
15
LT1996
U
W
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APPLICATIO S I FOR ATIO
R
F
Difference Amplifiers
The resistors in the LT1996 allow it to easily make differ-
ence amplifiers also. Figure 10 shows the basic 4-resistor
difference amplifier and the LT1996. A difference gain of
27 is shown, but notice the effect of the additional dashed
connections. By connecting the 50k resistors in parallel,
the gain is reduced by a factor of 10. Of course, with so
many resistors, there are many possible gains. Table 4
shows the difference gains and how they are achieved.
Note that, as for inverting amplifiers, the noise gain is 1
more than the signal gain.
R
R
G
G
–
+
V
V
–
+
IN
IN
V
OUT
–
V
= GAIN • (V + – V
IN
)
IN
OUT
GAIN = R /R
R
F
G
F
CLASSICAL DIFFERENCE AMPLIFIER USING THE LT1991
450k/81
450k
4pF
8
Table 4. Connections Giving Difference Gains for the LT1996
450k/27
450k/9
9
–
+
–
V
Gain
0.083
0.110
0.297
0.321
0.329
0.439
2.189
2.700
2.893
3.214
8.1
V
V
Output
M27, M81
M81
GND (REF)
P27, P81
P81
IN
IN
IN
P9
P9
M9
M9
10
–
+
PARALLEL
TO CHANGE
R , R
G
6
5
V
OUT
450k/9
450k/27
450k/81
1
2
3
P27
M27
M9, M81
M27
P9, P81
P27
F
P9
M9
4pF
+
V
IN
P27
M27
M81
P81
P9, P27
P81
M9, M27
M81
M81
P81
450k
M9, M27
M9
P9, P27
P9
LT1996
P27
M27
P81
M81
M27
P27
CLASSICAL DIFFERENCE AMPLIFIER IMPLEMENTED
WITH LT1991. R = 450k, R = 16.7k, GAIN = 3.
F
G
P9, P81
P81
M9, M81
M81
M27
P27
ADDING THE DASHED CONNECTIONS CONNECTS THE
M9
P9
TWO 450k RESISTOR IN PARALLEL, SO R IS REDUCED
F
TO 45k. GAIN BECOMES 45k/16.7k = 2.7.
1996 F10
9
P9
M9
10.8
27
P27, P81
P27
M27, M81
M27
M9
P9
Figure 10. Difference Amplifier Using the LT1996. Gain Is Set
Simply by Connecting the Correct Resistors or Combinations of
Resistors. Gain of 27 Is Shown, with Dashed Lines Modifying It
to Gain of 2.7. Noise Gain Is Optimal
36
P9, P27
P81
M9, M27
M81
81
90
P9, P81
P27, P81
M9, M81
M27, M81
108
117
P9, P27, P81 M9, M27, M81
1996f
16
LT1996
U
W
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APPLICATIO S I FOR ATIO
+
+
7
+
V
S
V
V
S
S
8
9
10
8
8
9
10
–
V
V
M81
M27
M9
M81
9
M81
M27
M9
IN
IN
7
7
M27
V
V
V
CC
CC
CC
10
–
+
–
+
V
V
V
V
M9
IN
IN
IN
6
6
6
6
6
6
6
LT1996
V
V
V
LT1996
V
V
V
LT1996
V
OUT
REF
5
OUT
REF
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
REF
P9
P27
P81
P9
P27
P81
P9
P27
P81
IN
5
5
V
V
V
EE
EE
EE
+
4
4
4
–
–
V
V
S
–
S
V
S
GAIN = 0.321
GAIN = 9
GAIN = 2.89
+
V
+
+
7
S
V
V
S
S
8
9
10
8
9
10
8
9
10
–
V
M81
M27
M9
M81
M27
M9
M81
M27
M9
IN
7
7
–
+
–
+
V
V
V
V
IN
IN
IN
IN
V
V
V
CC
CC
CC
6
LT1996
LT1996
LT1996
V
OUT
REF
5
OUT
OUT
1
2
3
1
2
3
1
2
3
REF
REF
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
V
V
V
EE
EE
EE
+
V
IN
4
4
4
–
–
V
V
S
–
S
V
S
GAIN = 27
GAIN = 36
GAIN = 8.1
+
7
+
7
+
V
S
V
V
S
S
–
–
–
8
9
10
8
9
10
8
9
10
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
V
V
V
CC
CC
CC
6
LT1996
LT1996
LT1996
V
OUT
REF
5
OUT
OUT
1
2
3
1
2
3
1
2
3
REF
REF
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
V
V
V
EE
EE
EE
+
+
+
4
4
4
–
–
–
V
V
V
S
S
S
GAIN = 10.8
GAIN = 81
GAIN = 90
+
+
V
V
S
S
–
8
9
10
–
8
9
10
V
V
IN
M81
M27
M9
IN
M81
M27
M9
7
7
V
V
CC
CC
6
6
LT1996
V
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
5
5
V
V
EE
EE
+
+
V
V
IN
IN
4
4
–
–
V
S
V
S
1996 F11
GAIN = 108
GAIN = 117
Figure 11. Many Difference Gains Are Achievable Just by Strapping the Pins
1996f
17
LT1996
U
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APPLICATIO S I FOR ATIO
450k/81
450k
4pF
8
450k/27
450k/9
9
–
V
IN
R
F
10
–
+
CROSS-
6
5
V
OUT
COUPLING
R
R
450k/9
450k/27
450k/81
G
1
2
3
–
+
V
V
–
+
IN
4pF
V
OUT
+
G
V
IN
IN
–
V
= GAIN • (V + – V
)
OUT
GAIN = R /R
IN IN
450k
R
F
F
G
LT1996
CLASSICAL DIFFERENCE AMPLIFIER IMPLEMENTED
WITH LT1991. R = 450k, R = 16.7k, GAIN = 27.
CLASSICAL DIFFERENCE AMPLIFIER
F
G
GAIN CAN BE ADJUSTED BY "CROSS COUPLING." MAKING THE
DASHED CONNECTIONS REDUCE THE GAIN FROM 3 T0 2.
WHEN CROSS COUPLING, SEE WHAT IS CONNECTED TO THE
V
IN
+ VOLTAGE. CONNECTING P27 AND M9 GIVES 27 – 9 = 18.
CONNECTIONS TO V – ARE SYMMETRIC: M27 AND P9.
1996 F10
IN
Figure 12. Another Method of Selecting Difference Gain Is “Cross-Coupling.”
The Additional Method Means the LT1996 Provides Extra Integer Gains
+
7
V
+
V
S
S
Difference Amplifier: Additional Integer Gains Using
Cross-Coupling
8
9
10
8
9
10
–
M81
M27
M9
V
M81
M27
M9
IN
7
–
V
V
IN
V
V
CC
CC
6
6
Figure 12 shows the basic difference amplifier as well as
the LT1996 in a difference gain of 27. But notice the effect
oftheadditionaldashedconnections. Thisisreferredtoas
“cross-coupling” and has the effect of reducing the differ-
ential gain from 27 to 18. Using this method, additional
integer gains are achievable, as shown in Table 5 below.
Note that the equations can be written by inspection from
the VIN+ connections, and that the VIN– connections are
simply the opposite (swap P for M and M for P). The
method is the same as for the LT1991, except that the
LT1996 applies a multiplier of 9. Noise gain, bandwidth,
and input impedance specifications for the various cases
are also tabulated, as these are not obvious. Schematics
are provided in Figure 13.
LT1996
V
OUT
LT1996
V
OUT
OUT
REF
OUT
REF
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
+
5
5
IN
V
V
V
EE
EE
+
V
IN
4
4
–
–
V
S
S
GAIN = 18
GAIN = 54
+
V
+
V
S
S
–
8
9
10
8
9
10
–
V
IN
V
IN
M81
M27
M9
M81
M27
M9
7
7
V
V
CC
CC
6
6
LT1996
V
OUT
LT1996
OUT
REF
OUT
REF
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
5
5
V
EE
V
V
EE
+
V
IN
+
4
V
IN
4
–
V
–
S
S
GAIN = 45
GAIN = 63
+
7
+
V
S
V
S
–
–
8
9
10
8
9
10
V
V
IN
IN
M81
M27
M9
M81
M27
M9
7
V
CC
V
CC
Table 5. Connections Using Cross-Coupling. Note That Equations
6
6
Can Be Written by Inspection of the VIN+ Column
LT1996
V
LT1996
V
OUT
OUT
OUT
OUT
1
2
3
1
2
3
REF
REF
P9
P27
P81
P9
P27
P81
+
–
5
5
V
EE
V
EE
Gain Noise –3dB BW
Equation Gain kHz Typ kΩ Typ kΩ
27 – 9 39
R
R
IN
IN
+
+
V
V
IN
IN
+
–
4
–
4
–
Gain
V
V
IN
IN
V
V
S
S
18
P27, M9
M27, P9
14
5
46
12
16
16
45
45
16
6
1996 F13
GAIN = 99
GAIN = 72
45 P81, M27, M9 M81, P27, P9 81 – 27 – 9 117
54 P81, M27 M81, P27 81 – 27 108
63 P81, P9, M27 M81, M9, P27 81 + 9 – 27 117
72 P81, M9 M81, P9 81 – 9 90
5
6
Figure 13. Integer Gain Difference
Amplifiers Using Cross-Coupling
5
5
6
6
99 P81, P27, M9 M81, M27, P9 81 + 27 – 9 117
5
4
1996f
18
LT1996
U
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APPLICATIO S I FOR ATIO
Table 6. HighV CM Connections Giving Difference Gains
for the LT1996
High Voltage CM Difference Amplifiers
This class of difference amplifier remains to be discussed.
Figure 14 shows the basic circuit on the top. The effective
input voltage range of the circuit is extended by the fact
that resistors RT attenuate the common mode voltage
seen by the op amp inputs. For the LT1996, the most
useful resistors for RG are the M9 and P9 50kΩ resistors,
becausetheydonothavediodeclampstothesuppliesand
therefore can be taken outside the supplies. As before, the
input CM of the op amp is the limiting factor and is set by
the voltage at the op amp +input, VINT. By superposition
we can write:
Max, Min V
EXT
Noise
Gain
(Substitute V – 1.2,
CC
+
–
Gain
V
IN
V
R
V
EE
+ 1 for V
)
IN
T
LIM
9
9
9
9
P9
P9
P9
P9
M9
10
10/9 • V - V /9
LIM REF
M9 P27, M27 37
M9 P81, M81 91
37/9 • V – V /9 – 3 • V
LIM REF
TERM
91/9 • V – V /9 – 9 • V
LIM
REF
TERM
M9
P27||P81 118 118/9 • V – V /9 – 12 • V
LIM REF TERM
M27||M81
R
F
V
CC
R
G
VINT = VEXT • (RF||RT)/(RG + RF||RT) + VREF • (RG||RT)/
(RF + RG||RT) + VTERM • (RF||RG)/(RT + RF||RG)
–
+
V
–
+
IN
V
OUT
R
G
V
EXT
IN
Solving for VEXT
:
–
(= V
)
V
= GAIN • (V + – V
)
OUT
GAIN = R /R
IN IN
F
G
V
EE
R
T
R
T
VEXT = (1 + RG/(RF||RT)) • (VINT – VREF • (RG||RT)/
(RF + RG||RT) – VTERM • (RF||RG)/(RT + RF||RG))
R
F
V
REF
V
TERM
Given the values of the resistors in the LT1996, this
equation has been simplified and evaluated, and the re-
sulting equations provided in Table 6. As before, substi-
tuting VCC – 1.2 and VEE + 1 for VLIM will give the valid
upper and lower common mode extremes respectively.
Following are sample calculations for the case shown in
Figure 14, right-hand side. Note that P81 and M81 are
terminated so row 3 of Table 6 provides the equation:
HIGH CM VOLTAGE DIFFERENCE AMPLIFIER
INPUT CM TO OP AMP IS ATTENUATED BY
RESISTORS R CONNECTED TO V
T
TERM.
12V
7
10V
450k/81
450k
8
4pF
450k/27
450k/9
9
10
MAX VEXT = 91/9 • (VCC – 1.2V) – VREF/9 – 9 • VTERM
–
+
6
5
V
OUT
= (10.11) • (10.8) – 0.11(2.5) – 9(10) =
18.9V
450k/9
450k/27
450k/81
1
2
3
–
+
4pF
V
IN
V
IN
and:
INPUT CM RANGE
= –60V TO 18.9V
450k
REF
MIN VEXT = 91/9 • (VEE + 1V) – VREF/9 – 9 • VTERM
= (10.11)(1) – 0.11(2.5) – 9(10) = –80.2V
2.5V
LT1996
4
but this exceeds the 60V absolute maximum rating of the
P9, M9 pins, so –60V becomes the de facto negative
common mode limit. Several more examples of high CM
circuits are shown in Figures 15, 16, 17 for various
supplies.
HIGH NEGATIVE CM VOLTAGE DIFFERENCE AMPLIFIER
IMPLEMENTED WITH LT1996.
R
= 450k, R = 50k, R 5.55k, GAIN = 9
F
G T
1996 F14
V
TERM
= 10V = V = 12V, V
CC REF
= 2.5V, V = 0V.
EE
Figure 14. Extending CM Input Range
1996f
19
LT1996
U
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APPLICATIO S I FOR ATIO
3V
3V
3V
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
7
V
V
V
CC
CC
CC
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
LT1996
V
LT1996
V
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
1.25V
4
4
4
3V
V
= 0.97V TO 1.86V
V
= 1.11V TO 2V
DM
V
= –.78V TO 1.67V
CM
CM
CM
V
> 45mV
V
<–45mV
DM
3V
3V
7
3V
7
3V
7
8
9
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
CC
V
V
CC
CC
10
–
–
–
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
LT1996
V
LT1996
V
OUT
V
OUT
V
OUT
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
+
+
+
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
1.25V
1.25V
1.25V
4
4
4
1.25V
V
= 0.22V TO 3.5V
V
= 4V TO 7.26V
V = –5V TO –1.74V
CM
CM
CM
3V
3V
7
3V
7
3V
7
8
9
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
CC
V
CC
CC
10
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
1.25V
1.25V
1.25V
4
4
4
1.25V
V
= –1.28V TO 6.8V
V
= 9.97V TO 18V
V = –17V TO –8.9V
CM
CM
CM
3V
3V
7
3V
7
3V
7
8
9
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
CC
V
CC
CC
10
–
–
+
–
V
V
V
IN
IN
IN
IN
IN
6
6
6
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
+
+
V
V
V
IN
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
1.25V
1.25V
1.25V
4
4
4
1.25V
V
= –2V TO 8.46V
V
= 12.9V TO 23.4V
V
= –23V TO –12.5V
CM
CM
CM
1996 F15
Figure 15. Common Mode Ranges for Various LT1996 Difference Amp Configurations on VS = 3V, 0V, with Gain = 9
1996f
20
LT1996
U
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APPLICATIO S I FOR ATIO
5V
5V
5V
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
7
V
V
V
CC
CC
CC
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
6
6
6
6
6
6
LT1996
V
LT1996
V
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
2.5V
4
4
4
5V
V
= –0.83V TO 3.9V
V
= 1.1V TO 4.2V
V
= –0.56V TO 3.7V
CM
CM
CM
V
> 5mV
V
<–5mV
DM
DM
5V
5V
7
5V
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
V
V
V
CC
CC
CC
–
–
–
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
LT1996
V
LT1996
V
OUT
V
OUT
V
OUT
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
+
+
+
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
2.5V
2.5V
2.5V
4
4
4
2.5V
V
= –3.7V TO 7.8V
V
= 3.8V TO 15.3V
V = –11.7V TO 0.3V
CM
CM
CM
5V
5V
7
5V
7
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
V
CC
CC
CC
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
2.5V
2.5V
2.5V
4
4
4
2.5V
V
= –12.6V TO 15.6V
V
= 9.8V TO 38.1V
V = –35.1V TO –6.8V
CM
CM
CM
5V
5V
7
5V
7
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
V
CC
CC
CC
–
+
–
+
–
V
V
V
IN
IN
IN
IN
IN
IN
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
+
V
V
V
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
2.5V
2.5V
2.5V
4
4
4
2.5V
V
= –17.1V TO 19.5V
V
= 12.8V TO 49.5V
V
= –47.2V TO –10.5V
CM
CM
CM
1996 F16
Figure 16. Common Mode Ranges for Various LT1996 Difference Amp Configurations on VS = 5V, 0V, with Gain = 9
1996f
21
LT1996
U
W U U
APPLICATIO S I FOR ATIO
5V
5V
5V
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
7
V
V
V
CC
CC
CC
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
6
6
6
6
6
6
6
6
6
6
6
6
LT1996
V
LT1996
V
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
4
4
4
5V
–5V
–5V
–5V
= –5V TO 3.7V
–5V
V
= –4.4V TO 4.2V
V
V
= –3.9V TO 4.8V
<–5mV
DM
CM
CM
CM
V
> 5mV
V
DM
5V
5V
7
5V
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
V
V
V
CC
CC
CC
–
+
–
–
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
LT1996
V
LT1996
V
OUT
V
OUT
V
OUT
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
OUT
OUT
OUT
1
2
3
1
2
3
1
2
3
+
+
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
4
4
4
2.5V
–5V
–5V
–5V
V
= –23.9V TO 8.1V
V
= –16.4V TO 15.6V
V = –31.4V TO 0.6V
CM
CM
CM
5V
5V
7
5V
7
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
V
CC
CC
CC
–
+
–
+
–
+
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
4
4
4
–5V
–5V
–5V
–5V
V
= –40.4V TO 38.4V
V
= 4.6V TO 60V
V = –60V TO –10.2V
CM
CM
CM
5V
5V
7
5V
7
5V
7
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
V
V
V
CC
CC
CC
–
+
–
+
–
V
V
V
IN
IN
IN
IN
IN
IN
LT1996
V
LT1996
LT1996
V
OUT
OUT
REF
OUT
REF
OUT
REF
1
2
3
1
2
3
1
2
3
+
V
V
V
P9
P27
P81
P9
P27
P81
P9
P27
P81
5
5
5
V
V
V
EE
EE
EE
4
4
4
–5V
–5V
= 7.6V TO 60V
–5V
= –52.4V TO 49.8V
–5V
= –60V TO –10.2V
V
V
V
CM
CM
CM
1996 F17
Figure 17. Common Mode Ranges for Various LT1996 Difference Amp Configurations on VS = ±5V, with Gain = 9
1996f
22
LT1996
U
PACKAGE DESCRIPTIO
DD Package
10-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1699)
R = 0.115
TYP
6
0.38 ± 0.10
10
0.675 ±0.05
3.50 ±0.05
2.15 ±0.05 (2 SIDES)
1.65 ±0.05
3.00 ±0.10
(4 SIDES)
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
(SEE NOTE 6)
PACKAGE
OUTLINE
(DD10) DFN 1103
5
1
0.25 ± 0.05
0.50 BSC
0.75 ±0.05
0.200 REF
0.25 ± 0.05
0.50
BSC
2.38 ±0.10
(2 SIDES)
2.38 ±0.05
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).
CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.889 ± 0.127
(.035 ± .005)
0.497 ± 0.076
(.0196 ± .003)
10 9
8
7 6
REF
5.23
(.206)
MIN
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
3.20 – 3.45
(.126 – .136)
4.90 ± 0.152
(.193 ± .006)
DETAIL “A”
0° – 6° TYP
0.254
(.010)
GAUGE PLANE
0.50
(.0197)
BSC
0.305 ± 0.038
(.0120 ± .0015)
TYP
1
2
3
4 5
0.53 ± 0.152
(.021 ± .006)
0.86
(.034)
REF
1.10
(.043)
MAX
RECOMMENDED SOLDER PAD LAYOUT
DETAIL “A”
0.18
(.007)
SEATING
PLANE
NOTE:
0.17 – 0.27
(.007 – .011)
TYP
0.127 ± 0.076
(.005 ± .003)
MSOP (MS) 0603
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
0.50
(.0197)
BSC
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
1996f
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
23
LT1996
U
TYPICAL APPLICATIO
Micropower AV = 90 Instrumentation Amplifier
V
OUT
10
9
8
7
6
450k
450k/81
+
V
M
4pF
450k/27
450k/9
1/2 LT6011
–
–
+
450k/9
+
LT1996
450k
V
P
450k/27
1/2 LT6011
–
450k/81
4pF
1
2
3
4
5
1996 TA02
Bidirectional Controlled Current Source
AC Coupled Amplifier
Differential Input/Output G = 9 Amplifier
+
V
+
V
+
V
S
S
S
8
9
10
8
9
10
8
9
10
M81
M27
M9
M81
M27
M9
M81
M27
M9
7
7
7
–
–
+
V
V
V
IN
IN
IN
6
6
6
+
LT1996
LT1996
V
LT1996
V
OUT
OUT
1
2
3
1
2
3
1
2
3
+
V
R1
IN
P9
P27
P81
P9
P27
P81
5
5
P9
P27
P81
5
V
OCM
0.1µF
10k
10k
10k
–
V
IN
4
4
4
LT6010
+ –
–
)
9(V
V
IN
10kΩ
IN
I
=
LOAD
–
V
–
–
V
V
S
S
S
GAIN = 117
BW = 4Hz TO 5kHz
USE V
TO SET THE DESIRED
OCM
OUTPUT COMMON MODE LEVEL
–
V
OUT
1996 TA03
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1990
High Voltage Difference Amplifier
±250V Input Common Mode, Micropower, Pin Selectable Gain = 1, 10
Gain Resistors of 450k, 150k, 50k
LT1991
Precision, 100µA Gain Selectable Amplifier
30MHz, 1000V/µs Gain Selectable Amplifier
Single/Dual/Quad Precision Op Amp
LT1995
High Speed, Pin Selectable Gain = –7 to 8
LT6010/LT6011/LT6012
Similar Performance as LT1996 Diff Amp, 135µA, 14nV√Hz,
Rail-to-Rail Out
LT6013/LT6014
LTC6910-X
Single/Dual Precision Op Amp
Programmable Gain Amplifiers
Lower Noise A ≥ 5 Version of LT1991, 145µA, 8nV/√Hz,
Rail-to-Rail Out
V
3 Gain Configurations, Rail-to-Rail Input and Output
1996f
LT/TP 0205 1K • PRINTED IN USA
24 LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
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●
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