LINEAR TECHNOLOGY LTC6800 Technical data

FEATURES

LTC6800

Rail-to-Rail

Input and Output,

Instrumentation Amplifier

U

DESCRIPTIO

■

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 an MS8 and 3mm × 3mm × 0.8mm
DFN Packages

U

APPLICATIO S

■

Thermocouple Amplifiers

■

Electronic Scales

■

Medical Instrumentation

■

Strain Gauge Amplifiers

■

High Resolution Data Acquisition

U

TYPICAL APPLICATIO

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 tech­niques 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).

, LTC and LT are registered trademarks of Linear Technology Corporation.

V

REGULATOR

High Side Power Supply Current Sense Typical Input Referred Offset vs

Input Common Mode Voltage (VS = 3V)

1.5mΩ

2

3

–

LTC6800

+

4

8

7

6

10k

5

0.1µF

150Ω

OUT
100mV/A
OF LOAD
CURRENT

I

LOAD

LOAD

6800 TA01

15

VS = 3V

= 0V

V

REF

10

= 25°C

T

A

5

(µV)

0

OS

V

–5

–10

–15

0

1 1.5 2

0.5

INPUT COMMON MODE VOLTAGE (V)

G = 1000

G = 100

G = 10

G = 1

2.5 3

6800 TA02

sn6800 6800fas

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LTC6800

WW

W

U

ABSOLUTE AXI U RATI GS

(Note 1)

Total Supply Voltage (V+ to V–) .............................. 5.5V

Input Current ...................................................... ±10mA

+

V
V

IN
IN

– V

–

– V

 ........................................................ 5.5V

REF

 ........................................................ 5.5V

REF

Output Short Circuit Duration .......................... Indefinite

UUW

PACKAGE/ORDER I FOR ATIO

ORDER PART NUMBER

LTC6800HMS8

TOP VIEW

NC

1

–IN

2

+IN

3
4

–

V

MS8 PACKAGE

8-LEAD PLASTIC MSOP

T

= 150°C, θJA = 200°C/W

JMAX

+

8

V

7

OUT

6

RG

5

REF

MS8 PART MARKING

LTADE

Operating Temperature Range

(Note 7) ................................................ – 40°C to 125°C

Storage Temperature Range

MS8 Package ................................... – 65°C to 150°C

DD Package ...................................... –65°C to 125°C

Lead Temperature (Soldering, 10 sec)..................300°C

TOP VIEW

NC

1

–IN

2

+IN

3

–

V

4

8-LEAD (3mm × 3mm) PLASTIC DFN

DD PACKAGE

T

= 125°C, θJA = 160°C/W

JMAX

UNDERSIDE METAL INTERNALLY

CONNECTED TO V

(PCB CONNECTION OPTIONAL)

+

V

8

OUT

7

RG

6

REF

5

–

ORDER PART NUMBER

LTC6800HDD

DD PART MARKING

LAEP

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. V+ = 3V, V– = 0V, REF = 200mV. Output voltage swing is referenced
to V–. All other specifications reference the OUT pin to the REF pin.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Input Offset Voltage (Note 2) VCM = 200mV ±100 µV
Average Input Offset Drift (Note 2) TA = –40°C to 85°C ● ±250 nV/°C

= 85°C to 125°C ● –1 –2.5 µV/°C

T

A

Common Mode Rejection Ratio AV = 1, VCM = 0V to 3V ● 85 113 dB
(Notes 4, 5)

Integrated Input Bias Current (Note 3) VCM = 1.2V 4 10 nA
Integrated Input Offset Current (Note 3) VCM = 1.2V 1 3 nA
Input Noise Voltage DC to 10Hz 2.5 µV
Power Supply Rejection Ratio (Note 6) VS = 2.7V to 5.5V ● 110 116 dB
Output Voltage Swing High RL = 2k to V

= 10k to V

R

L

Output Voltage Swing Low ● 20 mV
Gain Error AV = 1 0.1 %
Gain Nonlinearity AV = 1 100 ppm

–

–

● 2.85 2.94 V

● 2.95 2.98 V

P-P

2

sn6800 6800fas

LTC6800

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 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.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Supply Current No Load ● 1.2 mA
Internal Op Amp Gain Bandwidth 200 kHz
Slew Rate 0.2 V/µs
Internal Sampling Frequency 3kHz

The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 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 CONDITIONS MIN TYP MAX UNITS

Input Offset Voltage (Note 2) VCM = 200mV ±100 µV
Average Input Offset Drift (Note 2) TA = –40°C to 85°C ● ±250 nV/°C

= 85°C to 125°C ● –1 –2.5 µV/°C

T

A

Common Mode Rejection Ratio AV = 1, VCM = 0V to 5V ● 85 116 dB
(Notes 4, 5)

Integrated Input Bias Current (Note 3) VCM = 1.2V 4 10 nA
Integrated Input Offset Current (Note 3) VCM = 1.2V 1 3 nA
Power Supply Rejection Ratio (Note 6) VS = 2.7V to 5.5V ● 110 116 dB
Output Voltage Swing High RL = 2k to V

R

= 10k to V

L

Output Voltage Swing Low ● 20 mV
Gain Error AV = 1 0.1 %
Gain Nonlinearity AV = 1 100 ppm
Supply Current No Load ● 1.3 mA
Internal Op Amp Gain Bandwidth 200 kHz
Slew Rate 0.2 V/µs
Internal Sampling Frequency 3kHz

–

–

● 4.85 4.94 V

● 4.95 4.98 V

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. V
capability.

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, AV, 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.

is measured to a limit determined by test equipment

OS

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
but are not tested or QA sampled at these temperatures.

●) are assured by design and characterization

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LTC6800

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TYPICAL PERFOR A CE CHARACTERISTICS

Input Offset Voltage
vs Input Common Mode Voltage

15

VS = 3V

= 0V

V

REF

= 25°C

T

10

A

5

0

–5

INPUT OFFSET VOLTAGE (µV)

–10

–15

0

1.0 1.5 2.0

0.5

INPUT COMMON MODE VOLTAGE (V)

G = 1000

Input Offset Voltage
vs Input Common Mode Voltage

20

VS = 5V

= 0V

V

REF

15

G = 10

10

5

0

–5

–10

INPUT OFFSET VOLTAGE (µV)

–15

–20

0

TA = 25°C

TA = –55°C

234

1

INPUT COMMON MODE VOLTAGE (V)

Additional Input Offset Due to
Input RS vs Input Common Mode
(CIN < 100pF)

60

VS = 3V

= 0V

V

REF
+

= R– = R

R

–20

–40

ADDITIONAL OFFSET ERROR (µV)

–60

40

20

0

0

CIN < 100pF
G = 10
T

SMALL C

S

= 25°C

A

R

S

IN

R

S

1.0 1.5 2.0

0.5

INPUT COMMON MODE VOLTAGE (V)

RS = 10k

+

–

RS = 5k

RS = 15k

RS = 20k

G = 10

2.5 3.0

TA = 70°C

2.5 3.0

G = 100

G = 1

6800 G01

6800 G04

RS = 0k

6800 G07

Input Offset Voltage
vs Input Common Mode Voltage

15

VS = 5V

= 0V

V

REF

= 25°C

T

10

A

G = 10

G = 1000

G = 100

G = 1

5

2053 G02

5

0

–5

INPUT OFFSET VOLTAGE (µV)

–10

–15

0

INPUT COMMON MODE VOLTAGE (V)

234

1

Input Offset Voltage vs Input
Common Mode Voltage,
85°C ≤ TA ≤ 125°C

60

VS = 3V
V

= 0V

REF

G = 10

40

20

0

–20

INPUT OFFSET VOLTAGE (µV)

–40

5

–60

0

1.0 1.5 2.0 2.5 3.0

0.5

INPUT COMMON MODE VOLTAGE (V)

TA = 85°C

TA = 125°C

6800 G05

Additional Input Offset Due to
Input RS vs Input Common Mode
(CIN < 100pF)

30

VS = 5V

= 0V

–10

–20

ADDITIONAL OFFSET ERROR (µV)

–30

V

REF

+

–

= R

= R

R

20

IN

CIN < 100pF
G = 10

10

= 25°C

T

A

0

SMALL C

0

INPUT COMMON MODE VOLTAGE (V)

S

IN

R

S

+

IN

R

1

–

S

234

RS = 20k

RS = 15k

RS = 10k

RS = 5k

5

6800 G08

Input Offset Voltage
vs Input Common Mode Voltage

20

VS = 3V

= 0V

V

REF

15

G = 10

10

5

0

–5

–10

INPUT OFFSET VOLTAGE (µV)

–15

–20

TA = 25°C

TA = –55°C

0

1.0 1.5 2.0 2.5 3.0

0.5

INPUT COMMON MODE VOLTAGE (V)

TA = 70°C

Input Offset Voltage vs Input
Common Mode Voltage,
85°C ≤ TA ≤ 125°C

60

VS = 5V
V

= 0V

REF

G = 10

40

20

0

–20

INPUT OFFSET VOLTAGE (µV)

–40

–60

0

0

TA = 125°C

2345

1

INPUT COMMON MODE VOLTAGE (V)

Additional Input Offset Due to Input
RS Mismatch vs Input Common
Mode (CIN < 100pF)

50

VS = 3V

= 0V

V

40

REF

< 100pF

C

IN

30

G = 10

= 25°C

T

A

20
10

0
–10
–20
–30

SMALL C

ADDITIONAL OFFSET ERROR (µV)

–40
–50

0

R+ = 0k, R– = 5k

R+ = 5k, R– = 0k

R+ = 10k, R– = 0k

+

R

IN

–

R

0.5

INPUT COMMON MODE VOLTAGE (V)

R+ = 0k, R– = 15k

R+ = 0k, R– = 10k

+

–

R+ =15k, R– = 0k

1.0 1.5 2.0

sn6800 6800fas

6800 G03

TA = 85°C

6800 G06

2.5 3.0

6800 G09

4