Page 6

June 1999 TOKO, Inc.

TK15328

ISOLATION (FIGURE 8)

This is the cross talk between Ach and Bch.

1) Connect V

low level.

2) Connect AC volt meters to Pin 4 and Pin 3.

3) Connect a capacitor and a resistance to GND

from Pin 2.

4) Input a sine wave (10 kHz, 1 Vrms) to Pin 4.

5) Measure the level of Pin 4 and name this V4.

6) Measure the level of Pin 3 and name this V3.

7) Calculate:

ISO = 20 Log (V3 / V4)

This value is the isolation to Bch from Ach.

8) Next, reverse conditions at Pin 5 and Pin 8.

9) Change line of Pin 2 and Pin 4.

10) Input the same sine wave to Pin 2.

11) Measure and calculate in the same way.

This value is the isolation to Ach from Bch.

TEST CIRCUITS AND METHODS (CONT.)

Figure 7

Figure 8

SEPARATION (FIGURE 9)

This is the cross talk between 1ch and 2ch.

1) Connect either Pin 5 or Pin 8 to V

condition, or low level.

2) Connect AC volt meters to Pin 4 (or Pin 2) and Pin 10.

3) Connect Pin 9 and Pin 11 to GND through capacitors

and a resistance.

4) Input a sine wave (10 kHz, 1 Vrms) to Pin 2 and Pin 4.

5) Measure the level of Pin 4 and name this V5.

6) Measure the level of Pin 10 and name this V6.

7) Calculate:

SEP = 20 Log (V6 / V5)

This value is the separation to 2ch from 1ch.

VCC

+

VEE

+

+

+

10 K

VCC

+

+

VEE

+