OP77FJZ Datasheet OP77FJZ, OP77EZ, OP77FZ | P10-P12

Data Sheet OP77

Rev. G | Page 9 of 16

10

1

0.1

100 1k 10k 100k

FREQUENCY (Hz)

RMS NOISE (mV)

00320-016

V

S

= ±15V

T

A

= 25°C

Figure 15. Input Wideband Noise vs. Bandwidth (0.1 Hz to Frequency

Indicated)

1k

100

10

1

1 10 100 1k

FREQUENCY (Hz)

INPUT NOISE VOLTAGE (nV/

Hz)

00320-017

V

S

= ±15V

T

A

= 25°C

RESIST

ORS

INCLUDED

EXCLUDED

R

S

= 0

RS1 = RS2 = 200kΩ

THERMAL NOISE OF SOURCE

Figure 16. Total Input Noise Voltage vs. Frequency

32

28

24

20

16

12

8

4

0

1k 10k 100k 1M

FREQUENCY (Hz)

PEAK-TO-PEAK AMPLITUDE (V)

00320-018

V

S

= ±15V

T

A

= 25°C

Figure 17. Maximum Output Swing vs. Frequency

100

10

1

0 10 20 30 40

TOTAL SUPPLY VOLTAGE V+ TO V– (V)

POWER CONSUMPTION (mW)

00320-019

T

A

= 25°C

Figure 18. Power Consumption vs. Power Supply

20

15

10

5

0

100 1k 10k

LOAD RESISTANCE TO GROUND (Ω)

MAXIMUM OUTPUT (V)

00320-020

V

S

= ±15V

T

A

= 25°C

V

IN

= ±10mV

POSITIVE SWING

NEGA

TIVE SWING

Figure 19. Maximum Output Voltage vs. Load Resistance

40

35

30

25

20

15

0 1 2 3 4

TIME FROM OUTPUT BEING SHORTENED (Minutes)

OUTPUT SHORT-CIRCUIT CURRENT (mA)

00320-021

V

S

= ±15V

T

A

= 25°C

Figure 20. Output Short-Circuit Current vs. Time

OP77 Data Sheet

Rev. G | Page 10 of 16

TEST CIRCUITS

OP77

200kΩ

V

O

50Ω

V

OS

=

V

O

4000

00320-022

Figure 21. Typical Offset Voltage Test Circuit

INPUT REFERRED NOISE =

V

O

25,000

00320-023

OP77

2.5MΩ

V+

V–

OUTPUT

100Ω

3.3kΩ

4.7µF

(≈10Hz FILTER)

7

6

4

2

3

Figure 22. Typical Low-Frequency Noise Test Circuit

00320-024

OP77

V+

OUTPUT

V–

20kΩ

INPUT

+

–

1

8

7

6

4

2

3

Figure 23. Optional Offset Nulling Circuit

00320-025

OP77

100kΩ

+18V

–18V

7

6

4

2

3

+

10µF

+

10µF

0.1µF

*

10Ω

10kΩ10kΩ

NOTES

*

1 PER BOARD

Figure 24. Burn-In Circuit

1MΩ

R

L

V

X

10Ω

10kΩ

100kΩ

V

IN

= ±10V

TYPICAL

PRECISION

OP AMP

V

Y

V

X

–10V 0V +10V

NOTES

1. GAIN NOT CONSISTANT. CAUSES NONLINEAR ERRORS.

2. A

VO

SPEC IS ON

LY PART OF THE SOLUTION.

3. CHECK SPECIFICATION TABLE 1 AND

TABLE 2 FOR PERFORMANCE.

00320-026

A

VO

650V/mV

R

L

= 2kΩ

Figure 25. Open-Loop Gain Linearity

Actual open-loop voltage gain can vary greatly at various output

voltages. All automated testers use endpoint testing and therefore

only show the average gain. This causes errors in high closed-

loop gain circuits. Because this is difficult for manufacturers to

test, users should make their own evaluations. This simple test

circuit makes it easy. An ideal op amp would show a horizontal

scope trace.

V

Y

V

X

–10V 0V +10V

00320-027

Figure 26. Output Gain Linearity Trace

This is the output gain linearity trace for the new OP77. The

output trace is virtually horizontal at all points, assuring

extremely high gain accuracy. The average open-loop gain is

truly impressive—approximately 10,000,000.

Data Sheet OP77

Rev. G | Page 11 of 16

APPLICATIONS

00320-028

OP77E

R2

1MΩ

R4

1MΩ

+15V

–15V

R1

1kΩ

R3

1kΩ

7

6

4

2

3

0.1µF

Figure 27. Precision High-Gain Differential Amplifier

The high gain, gain linearity, CMRR, and low TCV

OS

of the

OP77 make it possible to obtain performance not previously

available in single-stage, very high-gain amplifier applications.

For best CMR,

2R

1R

must equal

4R

3R

. In this example, with a

10 mV differential signal, the maximum errors are as listed in

Table 7.

Table 7. Maximum Errors

Type Amount

Common-Mode Voltage 0.01%/V

Gain Linearity, Worst Case 0.02%

TCV

OS

0.003%/°C

TCI

OS

0.008%/°C

00320-029

+15V

–15V

R

S

R

F

100Ω

7

6

4

2

3

0.1µF

10µF

OUTPUT

INPUT

C

LOAD

OP77

Figure 28. Isolating Large Capacitive Loads

This circuit reduces maximum slew rate but allows driving

capacitive loads of any size without instability. Because the boon

resistor is inside the feedback loop, its effect on output

impedance is reduced to insignificance by the high open-loop

gain of the OP77.

00320-030

R1

100kΩ

R3

1kΩ

R4

990Ω

R5

10Ω

6

2

3

V

IN

I

OUT

< 15mA

R2

100kΩ

OP77

Figure 29. Basic Current Source

00320-031

R1

R3

+15V

–15V

R4

R5

6

2N2222

2N2907

2

3

V

IN

R2

OP77

I

OUT

= V

IN

( )

GIVEN R3 = R4 + R5, R1 = R2

R3

R1 – R5

I

OUT

< 100m

A

Figure 30. 100 mA Current Source

These current sources can supply both positive and negative

current into a grounded load.

Note that

1R

3R

2

R

4R

5R

2

R

4R

5

R

Z

O

+













+

=

1

And that for Z

O

to be infinite

2R

4R5R +

must =

1R

3R

OP77FJZ

OP77FJZ

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