REV. A

OP27

–15–

Some comment on noise is appropriate to understand the

capability of this circuit. A 150

Ω resistor and R1 and R2

gain resistors connected to a noiseless amplifier will generate

220 nV of noise in a 20 kHz bandwidth, or 73 dB below a 1 mV

reference level. Any practical amplifier can only approach this noise

level; it can never exceed it. With the OP27 and T1 specified, the

additional noise degradation will be close to 3.6 dB (or –69.5 refer-

enced to 1 mV).

OP27

V–

INPUT

V+

OUTPUT

10k

Figure 12. Offset Nulling Circuit

References

1. Lipshitz, S.R, “On RIAA Equalization Networks,” JAES,

Vol. 27, June 1979, p. 458–481.

2. Jung, W.G., IC Op Amp Cookbook, 2nd. Ed., H.W. Sams and

Company, 1980.

3. Jung, W.G., Audio IC Op Amp Applications, 2nd. Ed., H.W.

Sams and Company, 1978.

4. Jung, W.G., and Marsh, R.M., “Picking Capacitors,” Audio,

February and March, 1980.

5. Otala, M., “Feedback-Generated Phase Nonlinearity in

Audio Amplifiers,” London AES Convention, March 1980,

preprint 1976.

6. Stout, D.F., and Kautman, M., Handbook of Operational

Amplifier Circuit Design, New York, McGraw-Hill, 1976.

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

8-Lead PDIP Package (P-Suffix)

(N-8)

SEATING

PLANE

0.060 (1.52)

0.015 (0.38)

0.210

(5.33)

MAX

0.022 (0.558)

0.014 (0.356)

0.160 (4.06)

0.115 (2.93)

0.070 (1.77)

0.045 (1.15)

0.130

(3.30)

MIN

8

1

4

5

PIN 1

0.280 (7.11)

0.240 (6.10)

0.100 (2.54)

BSC

0.430 (10.92)

0.348 (8.84)

0.195 (4.95)

0.115 (2.93)

0.015 (0.381)

0.008 (0.204)

0.325 (8.25)

0.300 (7.62)

8-Lead SOIC Package (S-Suffix)

(R-8)

0.0098 (0.25)

0.0075 (0.19)

0.0500 (1.27)

0.0160 (0.41)

8

0

0.0196 (0.50)

0.0099 (0.25)

45

85

4

1

0.1968 (5.00)

0.1890 (4.80)

0.2440 (6.20)

0.2284 (5.80)

PIN 1

0.1574 (4.00)

0.1497 (3.80)

0.0500 (1.27)

BSC

0.0688 (1.75)

0.0532 (1.35)

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

8-Lead CERDIP Package (Z-Suffix)

(Q-8)

1

4

85

0.310 (7.87)

0.220 (5.59)

PIN 1

0.005 (0.13)

MIN

0.055 (1.4)

MAX

0.100 (2.54)

BSC

15

0

0.320 (8.13)

0.290 (7.37)

0.015 (0.38)

0.008 (0.20)

SEATING

PLANE

0.200 (5.08)

MAX

0.405 (10.29) MAX

0.150

(3.81)

MIN

0.200 (5.08)

0.125 (3.18)

0.023 (0.58)

0.014 (0.36)

0.070 (1.78)

0.030 (0.76)

0.060 (1.52)

0.015 (0.38)

8-Pin (TO-99) Header Package (J-Suffix)

(H-8A)

0.250 (6.35) MIN

0.750 (19.05)

0.500 (12.70)

0.185 (4.70)

0.165 (4.19)

REFERENCE PLANE

0.050 (1.27) MAX

0.019 (0.48)

0.016 (0.41)

0.021 (0.53)

0.016 (0.41)

0.045 (1.14)

0.010 (0.25)

0.040 (1.02) MAX

BASE & SEATING PLANE

0.034 (0.86)

0.027 (0.69)

0.045 (1.14)

0.027 (0.69)

0.160 (4.06)

0.110 (2.79)

0.100 (2.54) BSC

6

2

8

7

5

4

3

1

0.200

(5.08)

BSC

0.100

(2.54)

BSC

45 BSC