May 1999 TOKO, Inc.

Page 3

TK15321

TEST CIRCUITS AND METHODS

SW6

~

10 kHz

1 Vrms

SW8

10 k

Ω

SW7

SW3

V

~

V

_

THD

SW2

SW5

SW4

VCC

33 µF

SW1

LH

SW9

1 kHz

1 Vrms

or

2 Vrms

~

1: The above condition represents 1ch.

2: The above conditions distortion rate of 1-Ach and dynamic range measurement.

3: SW5 is for residual noise measurement.

4: SW8 is for cross talk (ISO or SEP) measurement.

CONTROL LOW/HIGH LEVEL (FIGURE 2)

This level is to measure the threshold level.

1) Input, the V

other measurements, omitted from the next for simplicity)

2) Input to Pin 4 with sine wave (f = 1 kHz, V

3) Connect an oscilloscope to Pin 3.

4) Elevate the control voltage from 0 V gradually, until the

sine wave appears at the oscilloscope. This voltage is

the threshold level when the wave appears.

Figure 1

A

VCC

SUPPLY CURRENT (FIGURE 1)

This current is a consumption current with a nonloading

condition.

1) Measure the inflow current to Pin 1 from V

This

current is the supply current.