W91620 SERIES

- 2 -

PIN CONFIGURATION

1

18

R4

C1

C2

C3

C4

V

2

3

4

5

6

13

14

15

16

17

R1

R2

R3

MODE

V

7

8

9

10

11

12

DTMF

DP/C5

HKS

XT

XT

T/P MUTE

P MUTE

DD

SS

PIN DESCRIPTION

SYMBOL

PIN NO.

I/O

FUNCTION

Column-

Row Inputs

1

−4

&

15

−18

I

Keyboard inputs are designed for use with either a standard 4

× 5

keyboard or an inexpensive single contact (Form A) keyboard.

Electronic input from a

µC can also be used.

Valid key entry is defined by a connection between a single row and

a single column.

XT, XT

7, 8

I, O

A built-in inverter provides oscillation with an inexpensive

3.579545 MHz crystal or ceramic resonator.

T/P MUTE

9

O

The T/P MUTE is a conventional CMOS inverter output. It is low

during pulse and tone mode dialing sequence and flash break;

otherwise, it remains high.

MODE

13

I

Mode pin.