®

INA103

12

FIGURE 12. Microphone Preamplifier with Provision for Phantom Power Microphones.

FIGURE 13. Instrumentation Amplifier with Shield Driver.

FIGURE 14. Gain-of-100 INA103 with FET Buffers.

11

10

7

VIN

16

15

13

14

6

2

1

INA103

∆

VIN

∆

V

= 100

OUT

–

+

OPA627

–

+

OPA627

Gain = 100V/V

(40dB)

11 10

7

16

15

13

14

6

2

1

VOUT

INA103

10

Ω

1k

Ω

Gain

Adjust

2.2k

Ω

240

Ω

47µF/63V

+

2.2k

Ω

240

Ω

47µF/63V

+

+48V

20dB

Pad

20dB

Pad

47k

Ω

6.8k

Ω

6.8k

Ω

1

3

2

cm

1µF

100k

Ω

–

+

OPA627

Phantom

Power

Output offset voltage

control loop.

12

5

16

15

13

14

6

2

1

INA103

11

10

7

V

OUT

10k

Ω

10k

Ω

VIN

∆

–

+

10k

Ω

10k

Ω

OPA602

100

Ω

Shield driver minimizes degradation of CMR due

to distributed capacitance on the input lines.