5

LTK001

001fa

AMPLIFIER (LTKA0x)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Offset Voltage

10

35

µV

Input 0ffset Voltage Drift with Temperature

(Note 6)

●

0.3

1.5

µV/°C

Input Bias Current

●

± 200

± 600

pA

●

± 300

± 1500

pA

Input Bias Current Drift with Temperature

(Note 6)

1

5

pA/°C

lnput 0ffset Current

●

± 100

± 500

pA

●

± 200

± 700

pA

lnput Offset Current Drift with Temperature

(Note 6)

●

0.6

4

pA/°C

Large Signal Voltage Gain

●

400

2000

V/mV

Common Mode Rejection Ratio

●

106

130

dB

Power Supply Rejection Ratio

●

106

125

dB

Common Mode Input Voltage Range

Notes 6, 7

0.75

V

1.0

V

Output Voltage Swing (Notes 6, 8)

Referred to Supplies

0.8

V

1.1

V

Supply Current

●

400

800

µA

Supply Voltage Range

●

4.5

40

V

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: The inputs of the LTKA0x amplifier are clamped with diodes, so a

differential voltage rating does not apply.

Note 3: Total temperature error is the overall error at 25°C taking into

account the offset of the amplifier, the offset at the compensator 10mV/°C

output, and the error in the compensator divider network. Warmup drift is

not included.

Note 4: Slope error is the increase in total temperature error as ambient

temperature is increased. It is guaranteed by design and by other tests,

but is not tested directly.

Note 5: This is a worst-case limit assuming that any or all supply voltages

change.

Note 6: Guaranteed, but not tested.

Note 7: By referring common mode range to the supplies, the range

referred to ground can be quickly calculated for any given supply voltage.

With a single 5V supply, for instance, which has a worst-case low value of

4.7V, the upper common mode limit is 4.7V – 1V = 3.7V. The lower

common mode limit is 0V + 0.75V = 0.75V. With ±15V supplies, the limits

would be 14V and –14.25V, respectively. Common mode range has a

temperature sensitivity of ≈ 2mV/°C.

Note 8: Absolute output voltage swing is calculated by subtracting the

given limits from actual supply voltage. These limits indicate the point

where offset voltage has changed suddenly by 5µV.

Note 9: Temperature error is defined as the deviation from the following

formula:

α = Typical thermocouple Seebeck coefficient as follows,

E = 60.9µV/°C, J = 51.7µV/°C, K, T = 40.6µV/°C, R, S = 5.95µV/°C.

α = 10mV/°C at the 10mV output.

ß = Nonlinearity coefficient built into the LT1025 to help compensate

for the nonlinearities of thermocouples.

0.34°C bow for 25°C temperature change, and 1.36°C bow for 50°C

change.

Note 10: Temperature error at the individual outputs is the sum of the

10mV/°C output error plus the resistor divider error.

Note 11: Line and load regulation do not take into account the effects of

self-heating. Output changes due to self-heating can be calculated as

follows:

= LT1025 supply current

Note 12: Larger errors with type R and S thermocouples are due mostly to

35µV offset of the amplifier. This error can be reduced to 5µV max with the

LTC

ELECTRICAL CHARACTERISTICS

The

(Amplifier LTKA0x)