9

LT1097

15V

–15V

OUT

LT1097•F01

4

3

2

7

6

50k

50k

50k

50k

+IN

–IN

+

–

LT1097

V–

OUT

V+

LT1097•F02

4

5

1

3

2

10k

POT

8

7

6

+

–

LT1097

Frequency Compensation and Optional Offset Nulling

±27V Common Mode Range Difference Amplifier

PARAMETER

LT1097CN8

OP-77GP

AD707JN

OP-177GP

OP-97FP

UNITS

Error Terms

50

100

90

60

75

µV

6

70

50

70

4

µV

Gain Min, 10V Out

14

5

3

5

50

µV

CMRR, Min,

±25V In

22

20

13

22

39

µV

69999

µV

Sum of All Error Terms

98

204

165

166

177

µV

0.1Hz to 10Hz Noise

Voltage Noise

0.5

0.38

0.23

0.38

0.5

µVp-p Typ

Current Noise•50k

0.11

0.75

0.7

0.75

0.1

µVp-p Typ

Resistor Noise

0.55

0.55

0.55

0.55

0.55

µVp-p Typ

RMS sum

0.75

1

0.92

1

0.75

µVp-p

Drift with Temp

1

1.2

1

1.2

2

µV/°C

0.1

2.1

1

2.1

0.2

µV/°C

Sum of Drift Terms

1.1

3.3

2

3.3

2.2

µV/°C

Supply Current Max

0.56

2

3

2

0.6

mA

The LT1097 is pin compatible to and directly replaces such

precision op amps as the OP-07, OP-77, AD707, OP-97, OP-

177, LM607 and LT1001 with improved price/performance.

Compatibility includes externally nulling the offset voltage, as

all of the above devices are trimmed with a potentiometer

The simple difference amplifier can be used to illustrate

the all-around excellence of the LT1097. The 50k input

resistance is selected to be large enough compared to

input signal source resistance. Simultaneously, the 50k

resistors should not dominate the precision and noise

error budget. Assuming perfect matching between the

four resistors, the following table summarizes the input

referred performance obtained using the LT1097 and

other popular, low cost precision op amps.

Input offset voltage can be adjusted over a

±600µV range

with a 10k potentiometer.

The LT1097 is internally compensated for unity gain

stability. As shown on the Capacitive Load Handling plot,

the LT1097 is stable with any capacitive load. However,

duce overshoot with heavy capacitive loads, to narrow

noise bandwidth or to stabilize circuits with gain in the

feedback loop.