LTC6800
Rail-to-Rail,
Input and Output,
Instrumentation Amplifier
FeaTures
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DescripTion
The LTC
®
6800 is a precision instrumentation amplifier.
The CMRR is typically 116dB with a single 5V supply and is
independent of gain. The input offset voltage is guaranteed
below 100µV with a temperature drift of less than 250nV/°C.
The LTC6800 is easy to use; the gain is adjustable with
two external resistors, like a traditional op amp.
The LTC6800 uses charge balanced sampled data tech-
niques to convert a differential input voltage into a single
ended signal that is in turn amplified by a zero-drift
operational amplifier.
The differential inputs operate from rail-to-rail and the
single ended output swings from rail-to-rail. The LTC6800
is available in an MS8 surface mount package. For space
limited applications, the LTC6800 is available in a 3mm ×
3mm × 0.8mm dual fine pitch leadless package (DFN).
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
116dB CMRR Independent of Gain
Maximum Offset Voltage: 100µV
Maximum Offset Voltage Drift: 250nV/°C
–40°C to 125°C Operation
Rail-to-Rail Input Range
Rail-to-Rail Output Swing
Supply Operation: 2.7V to 5.5V
Available in MS8 and 3mm × 3mm × 0.8mm
DFN Packages
applicaTions
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Thermocouple Amplifiers
Electronic Scales
Medical Instrumentation
Strain Gauge Amplifiers
High Resolution Data Acquisition
Typical applicaTion
High Side Power Supply Current Sense
V
REGULATOR
1.5m
Typical Input Referred Offset vs Input
Common Mode Voltage (V
S
= 3V)
15
10
V
S
= 3V
V
REF
= 0V
T
A
= 25°C
+
3
V
OS
(µV)
–
4
2
8
7
6
10k
0.1µF
150
LTC6800
5
OUT
100mV/A
OF LOAD
CURRENT
I
LOAD
LOAD
5
0
–5
G = 10
–10
G=1
6800 TA01
G = 1000
G = 100
–15
0
1
1.5
2
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3
6800 TA02
6800fb
LTC6800
absoluTe MaxiMuM raTings
(Note 1)
Total Supply Voltage (V
+
to V
–
) ...............................5.5V
Input Current........................................................ ±10mA
| V
+IN
– V
REF
|............................................................5.5V
| V
–IN
– V
REF
| ...........................................................5.5V
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range
(Note 7).................................................. –40°C to 125°C
Storage Temperature Range
DD Package ....................................... –65°C to 125°C
MS8 Package ..................................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
pin conFiguraTion
TOP VIEW
NC
–IN
+IN
V
–
1
2
3
4
9
8 V
+
7 OUT
6 RG
5 REF
NC 1
–IN 2
+IN 3
4
V
–
TOP VIEW
8
7
6
5
V
+
OUT
RG
REF
DD PACKAGE
8-LEAD (3mm 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 160°C/W
UNDERSIDE METAL INTERNALLY CONNECTED TO V
–
(PCB CONNECTION OPTIONAL)
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 200°C/W
orDer inForMaTion
LEAD FREE FINISH
LTC6800HDD#PBF
LTC6800HMS8#PBF
TAPE AND REEL
LTC6800HDD#TRPBF
LTC6800HMS8#TRPBF
PART MARKING*
LAEP
LTADE
PACKAGE DESCRIPTION
8-Lead (3mm
×
3mm) Plastic DFN
8-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
6800fb
LTC6800
elecTrical characTerisTics
PARAMETER
Input Offset Voltage (Note 2)
Average Input Offset Drift (Note 2)
Common Mode Rejection Ratio
(Notes 4, 5)
Integrated Input Bias Current (Note 3)
Integrated Input Offset Current (Note 3)
Input Noise Voltage
Power Supply Rejection Ratio (Note 6)
Output Voltage Swing High
Output Voltage Swing Low
Gain Error
Gain Nonlinearity
Supply Current
Internal Op Amp Gain Bandwidth
Slew Rate
Internal Sampling Frequency
A
V
= 1
A
V
= 1
No Load
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 3V, V
–
= 0V, REF = 200mV. Output voltage swing is referenced
to V
–
. All other specifications reference the OUT pin to the REF pin.
CONDITIONS
V
CM
= 200mV
T
A
= –40°C to 85°C
T
A
= 85°C to 125°C
A
V
= 1, V
CM
= 0V to 3V
V
CM
= 1.2V
V
CM
= 1.2V
DC to 10Hz
V
S
= 2.7V to 5.5V
R
L
= 2k to V
–
R
L
= 10k to V
–
l
l
l
l
l
l
l
MIN
TYP
MAX
±100
±250
–2.5
UNITS
µV
nV/°C
µV/°C
dB
–1
85
113
4
1
2.5
110
2.85
2.95
116
2.94
2.98
10
3
nA
nA
µV
P-P
dB
V
V
20
0.1
100
1.2
200
0.2
3
mV
%
ppm
mA
kHz
V/µs
kHz
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
+
= 5V, V
–
= 0V, REF = 200mV. Output voltage swing is referenced to V
–
. All other specifications reference the OUT pin to the REF pin.
PARAMETER
Input Offset Voltage (Note 2)
Average Input Offset Drift (Note 2)
Common Mode Rejection Ratio
(Notes 4, 5)
Integrated Input Bias Current (Note 3)
Integrated Input Offset Current (Note 3)
Power Supply Rejection Ratio (Note 6)
Output Voltage Swing High
Output Voltage Swing Low
Gain Error
Gain Nonlinearity
Supply Current
Internal Op Amp Gain Bandwidth
Slew Rate
Internal Sampling Frequency
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.
A
V
= 1
A
V
= 1
No Load
l
CONDITIONS
V
CM
= 200mV
T
A
= –40°C to 85°C
T
A
= 85°C to 125°C
A
V
= 1, V
CM
= 0V to 5V
V
CM
= 1.2V
V
CM
= 1.2V
V
S
= 2.7V to 5.5V
R
L
= 2k to V
–
R
L
= 10k to V
–
l
l
l
l
l
l
l
MIN
TYP
MAX
±100
±250
–2.5
UNITS
µV
nV/°C
µV/°C
dB
–1
85
116
4
1
110
4.85
4.95
116
4.94
4.98
10
3
nA
nA
dB
V
V
20
0.1
100
1.3
200
0.2
3
mV
%
ppm
mA
kHz
V/µs
kHz
Note 2:
These parameters are guaranteed by design. Thermocouple effects
preclude measurement of these voltage levels in high speed automatic
test systems. V
OS
is measured to a limit determined by test equipment
capability.
6800fb
LTC6800
elecTrical characTerisTics
Note 3:
If the total source resistance is less than 10k, no DC errors result
from the input bias currents or the mismatch of the input bias currents or
the mismatch of the resistances connected to –IN and +IN.
Note 4:
The CMRR with a voltage gain, A
V
, larger than 10 is 120dB (typ).
Note 5:
At temperatures above 70°C, the common mode rejection ratio
lowers when the common mode input voltage is within 100mV of the
supply rails.
Note 6:
The power supply rejection ratio (PSRR) measurement accuracy
depends on the proximity of the power supply bypass capacitor to the
device under test. Because of this, the PSRR is 100% tested to relaxed
limits at final test. However, their values are guaranteed by design to meet
the data sheet limits.
Note 7:
The LTC6800H is guaranteed functional over the operating
temperature range of –40°C to 125°C. Specifications over the –40°C to
125°C range (denoted by
l
) are assured by design and characterization
but are not tested or QA sampled at these temperatures.
Typical perForMance characTerisTics
Input Offset Voltage vs Input
Common Mode Voltage
15
10
5
0
–5
G = 10
–10
–15
G=1
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G01
Input Offset Voltage vs Input
Common Mode Voltage
15
V
S
= 5V
V
REF
= 0V
10 T
A
= 25°C
5
0
–5
–10
–15
G = 10
G = 100
G=1
G = 1000
20
Input Offset Voltage vs Input
Common Mode Voltage
V
S
= 3V
15 V
REF
= 0V
G = 10
10
5
0
–5
–10
–15
T
A
= 25°C
T
A
= –55°C
T
A
= 70°C
INPUT OFFSET VOLTAGE (µV)
G = 1000
G = 100
INPUT OFFSET VOLTAGE (µV)
INPUT OFFSET VOLTAGE (µV)
V
S
= 3V
V
REF
= 0V
T
A
= 25°C
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
5
2053 G02
–20
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G03
Input Offset Voltage vs Input
Common Mode Voltage
20
V
S
= 5V
15 V
REF
= 0V
G = 10
10
5
0
–5
–10
–15
–20
0
T
A
= 25°C
T
A
= 70°C
60
40
20
0
–20
–40
–60
Input Offset Voltage vs Input
Common Mode Voltage,
85°C ≤ T
A
≤ 125°C
V
S
= 3V
V
REF
= 0V
G = 10
60
40
20
0
–20
–40
–60
Input Offset Voltage vs Input
Common Mode Voltage,
85°C ≤ T
A
≤ 125°C
V
S
= 5V
V
REF
= 0V
G = 10
INPUT OFFSET VOLTAGE (µV)
INPUT OFFSET VOLTAGE (µV)
T
A
= 85°C
INPUT OFFSET VOLTAGE (µV)
T
A
= 85°C
T
A
= –55°C
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
5
6800 G04
T
A
= 125°C
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G05
T
A
= 125°C
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
5
6800 G06
6800fb
LTC6800
Typical perForMance characTerisTics
Additional Input Offset Due to
Input R
S
vs Input Common Mode
(C
IN
< 100pF)
60
ADDITIONAL OFFSET ERROR (µV)
40
20
0
–20
–40
–60
R
S
= 10k
R
S
SMALL C
IN
R
S
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G07
ADDITIONAL OFFSET ERROR (µV)
ADDITIONAL OFFSET ERROR (µV)
V
S
= 3V
V
REF
= 0V
R
+
= R
–
= R
S
C
IN
< 100pF
G = 10
T
A
= 25°C
30
Additional Input Offset Due to
Input R
S
vs Input Common Mode
(C
IN
< 100pF)
R
S
= 20k
R
S
= 5k
R
S
= 0k
V
S
= 5V
V
REF
= 0V
+
–
20 R
IN
= R
IN
= R
S
C
IN
< 100pF
G = 10
10 T
A
= 25°C
0
–10
R
S
50
40
30
20
10
0
–10
–20
–30
–40
5
–50
Additional Input Offset Due to
Input R
S
Mismatch vs Input
Common Mode (C
IN
< 100pF)
V
S
= 3V
V
REF
= 0V
C
IN
< 100pF
G = 10
T
A
= 25°C
R
+
= 0k, R
–
= 15k
R
S
= 15k
R
S
= 10k
R
S
= 5k
R
+
= 0k, R
–
= 10k
R
+
= 0k, R
–
= 5k
R
S
= 15k
+
–
R
S
= 20k
R
R
+
= 5k, R
–
= 0k
+
–
+
R = 10k, R = 0k
+
–
R
+
= 15k, R
–
= 0k
3.0
6800 G09
–20 SMALL C
IN
–30
R
S
0
+
–
SMALL C
IN
R
–
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
6800 G08
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
40
ADDITIONAL OFFSET ERROR (µV)
Additional Input Offset Due to
Input R
S
Mismatch vs Input
Common Mode (C
IN
< 100pF)
ADDITIONAL OFFSET ERROR (µV)
ADDITIONAL OFFSET ERROR (µV)
V
S
= 5V
R
IN+
= 0k, R
IN–
= 20k
V
REF
= 0V
30
C
IN
< 100pF
R
IN+
= 0k, R
IN–
= 15k
20 G = 10
R
IN+
= 0k, R
IN–
= 10k
T
A
= 25°C
R
IN+
= 10k, R
IN–
= 0k
10
0
R
IN+
= 15k, R
IN–
= 0k
–10
R
IN+
= 20k, R
IN–
= 0k
R
+
–20
+
SMALL C
IN
–30
–
R
–
–40
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
40
Additional Input Offset Due to
Input R
S
vs Input Common Mode
(C
IN
> 1µF)
70
R
S
= 15k
R
S
= 10k
R
S
= 5k
50
30
10
–10
–30
–50
–70
Additional Input Offset Due to
Input R
S
vs Input Common Mode
(C
IN
> 1µF)
R
S
= 10k
R
S
= 5k
R
S
= 1k
R
S
= 500
R
S
BIG C
IN
R
S
0
V
S
= 5V
V
REF
= 0V
R
+
= R
–
= R
S
C
IN
> 1µF
G = 10
T
A
= 25°C
5
6800 G12
V
S
= 3V
V
= 0V
30
REF –
R
+
= R = R
S
C > 1µF
20 G
IN
10
=
T
A
= 25°C
10
0
–10
–20
–30
–40
0
R
S
BIG C
IN
R
S
+
–
+
–
5
6800 G10
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G11
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
200
ADDITIONAL OFFSET ERROR (µV)
Additional Input Offset Due to
Input R
S
Mismatch vs Input
Common Mode (C
IN
> 1µF)
200
ADDITIONAL OFFSET ERROR (µV)
R
+
= 0 , R
–
= 1k
R
+
= 0 , R
–
= 500
Additional Input Offset Due to
Input R
S
Mismatch vs Input
Common Mode (C
IN
> 1µF)
V
S
= 5V
V
= 0V
150
REF
T
A
= 25°C
G = 10
100
50
0
–50
–100
–150
–200
0
R
+
BIG C
IN
R
–
Offset Voltage vs Temperature
80
60
INPUT OFFSET VOLTAGE (µV)
40
20
0
–20
–40
–60
V
S
= 3V
V
S
= 3V
V
= 0V
150
REF
T
A
= 25°C
G = 10
100
50
0
–50
R
+
BIG C
IN
R
–
R
+
= 0 , R
–
= 1k
R
+
= 0 , R
–
= 500
R
+
= 0 , R
–
= 100
+
–
R
+
= 0 , R
–
= 100
R = 100 , R = 0
R
+
= 500 , R
–
= 0
+
–
+
–
R = 100 , R = 0
R
+
= 500 , R
–
= 0
+
–
V
S
= 5V
–100
–150
–200
0
R
+
= 1k, R
–
= 0
R
+
= 1k, R
–
= 0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
6800 G13
4
3
INPUT COMMON MODE VOLTAGE (V)
1
2
5
6800 G14
–80
–50
–25
0
25
50
75
100
125
6800 G15
TEMPERATURE (°C)
6800fb