June 1999 TOKO, Inc.

Page 5

TK15323

TEST CIRCUITS AND METHODS (CONT.)

MAXIMUM INPUT LEVEL (FIGURE 6)

This measurement measures at output side.

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

2) Connect a distortion analyzer and an AC volt meter to

Pin 3.

3) Input a sine wave (1 kHz) to Pin 4 and elevate the

voltage gradually until the distortion gets to

0.1%.

4) When the distortion amounts to 0.1%, stop elevating and

measure the AC level of Pin 3.

This value is the maximum input level of 1-Ach.

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

6) Input the same sine wave to Pin 2.

7) Measure in the same way.

This value is the maximum input level of 1-Bch.

Figure 5

VOLTAGE GAIN (FIGURE 5)

This is the output level against input level.

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

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

(Using the same type meter is best)

3) Input a sine wave (f = max. 20 kHz, 1 Vrms) to Pin 4.

4) Measure the level of Pin 4 and name this V1.

5) Measure the level of Pin 3 and name this V2.

6) Calculate Gain = 20 Log (( |V2 - V1| )/V1)

V1<V2 + Gain, V1>V2 - Gain

This value is the voltage gain of 1-Ach.

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

8) Input the same sine wave to Pin 2.

9) Measure and calculate in the same way.

This value is the maximum input level of 1-Bch.

VCC

Cont.

+

+

Figure 4

VCC

Cont.

+

+