W91340N SERIES

Publication Release Date: May 1997

- 3 -

Revision A2

Pin Description, continued

SYMBOL

18-PIN 20-PIN

I/O

FUNCTION

DP

11

13

O

N-channel open drain dialing pulse output.

Flash key will cause DP to be active in either tone mode or

pulse mode.

The timing diagram for pulse mode is shown in Figure 1(a, b, c).

14, 6

16, 6

I

Power input pins.

DTMF

12

14

O

In pulse mode, this pin remains in low state at all times. In

the tone mode, it will output a dual or single tone. Detailed

timing diagram for tone mode is shown in Figure 2(a, b, c).

Specified

Actual

Error %

Output Frequency

R1

R2

R3

R4

C1

C2

C3

697

770

852

941

1209

1336

1477

699

766

848

948

1216

1332

1472

+0.28

-0.52

-0.47

+0.74

+0.57

-0.30

-0.34

HFI, HFO

-

10, 11

I, O

Handfree control pins. The handfree control state is toggled

on by a low pulse on the HFI input pin. The status of the

handfree control state is described in the following table:

CURRENT STATE

Input

HFO

Dialing

High

Yes

On Hook

High

Low

No

Off Hook

High

Low

Yes

On Hook

Off Hook

Low

Yes

Off Hook

Low

On Hook

Low

No

Off Hook

High

On Hook

High

Yes

Low

Hook SW.

HFO

NEXT STATE

HFI

HFI

HFI

Detailed timing diagram is shown in Figure 3.

H/P MUTE

5

5

O

The H/P MUTE is a conventional inverter output. During

pulse dialing, flash break or hold period, this output is active

high; otherwise, it remains in low state.