Page 6

May 1999 TOKO, Inc.

TK15321

ISOLATION (FIGURE 8)

This is the cross talk between Ach and Bch.

1) Pin 5 is in the open condition, or high level.

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

3) Connect a capacitor and a resistance in series to GND

from Pin 4.

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

5) Measure the level of Pin 2 and name this V3.

6) Measure the level of Pin 3 and name this V4.

7) Calculate:

ISO = 20 Log (V4 / V3)

This value is the isolation to Ach from Bch.

8) Next, connect Pin 5 to the GND, or low level.

9) Change line of Pin 2 and Pin 4.

10) Input the same sine wave to Pin 4.

11) Measure and calculate in the same way.

This value is the isolation to Bch from Ach.

TEST CIRCUITS AND METHODS (CONT.)

VCC

Cont.

+

+

Figure 7

SEPARATION (FIGURE 9)

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

1) Control level is free for Pin 5 and Pin 8.

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

Cont.

+

+

+

10 K

Figure 8