IL9151-3

PIN DESCRIPTION

PIN No.

NAME

DESCRIPTION

1

2

3

4

14

15

16

R1~R4

C1~C3

Key inputs.

These inputs can be interfaced to either an XY matrix keyboard or a 2 of 7 type

keyboard. The keypad inputs are normally held at high. When a key is depressed,

scanning signals are presented at C1, C2, and C3 inputs; the dialer identifies the

key by examining the R1~R4 inputs. Debouncing is provided to avoid false entry.

5

12

GND

Positive power supply input.

Negative power supply input.

6

7

8

CK1,CK,

CK

Oscillator circuit input/output.

The oscillator consists of two inverters, with oscillator frequency controlled by

external RC components:

9

__

DP

Dialing pulse output.

This output consists of an N-channel open drain device. Normally this output will

be in off state during make and on during break. Dialing pulse rate = 10pps and

10

M/B

Make/Break ratio select input.

In normal mode, this input is used to select the Make/Break ratio:

when input = GND, M/B ratio = 2/3.

when connected to the clock output (pin 7), this input can trigger the IN9151-3

into test mode, generating high speed dialing.

11

__

HK

Hook switch input.

This input is used to detect whether the telephone is in the On-Hook or Off-Hook

state:

GND=off-hook.

(Resetting time = 200 ms minimum)

13

MUTE

Mute output.

This output is an inverter normally at low state when there is no key entry.

During outdialing it changes to high state and is used to mute the speech network.