May 1999 TOKO, Inc.

Page 7

TK15321

TEST CIRCUITS AND METHODS (CONT.)

I/O TERMINAL VOLTAGE (FIGURE 10)

This is the DC voltage of input and output.

Because the input and the output are nearly equal, only the

output is measured.

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

2) Connect a DC volt meter to Pin 3 and measure.

This value is the terminal voltage of 1-Ach.

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

4) Measure in the same way.

This value is the terminal voltage of 1-Bch.

OUTPUT TERMINAL DIFFERENCE

This is the DC output voltage difference between Ach and

Bch. This is calculated by using values measured at the

I/O Terminal Voltage.

∆ Vcent = | (1 - Ach value) - (1 - Bch value) |

This value is the voltage difference of 1ch.

VCC

Cont.

+

+

+

10 K

+

+

VCC

Cont.

+

Figure 10

Figure 9