Rev. 2.0

ICmic reserves the right to change the specifications without prior notice

3

PIN DESCRIPTION

Pin No

Symbol

Description

1

AGND

Analog Ground

2

VDD

Supply Voltage

3

VDDI

Supply Input Voltage

Power for the chip is extracted from this pin

4

GND

Ground

5

TXO

Transmit Output

Transmit output to be connected to external power transistor for the

modulation of line voltage and for shorting the line during make period of pulse

dialing.

6

VL

Line Voltage

7

LLC

Line Loss Compensation

0V = No LLC;

AGND=Low LLC;

VDD=High LLC.

8

FOPT0

Flash Option

FOPT0=0 - 100ms

FOPT0=1 - 600ms

9

MFL0

DTMF Level Option

MFL0=0 - Low DTMF (~ -8/-10dB for ZAC=600ohm)

MFL0=1 - High DTMF (~ -6/-8dB for ZAC=600ohm)

10

HS/DPB

Hook Switch Input and Dial Pulse Output

When off-hook, this pin is pulled high by the hook switch. During pulse dialing,

this pin is pulled low during break periods.

11

OSC1

Oscillator Input

3.58MHz ceramic resonator input.

12

OSC2

Oscillator Output

13

RGD

Ring Detection Input

Input for ring frequency detection.

14

MO

Melody Output

Melody pulse output for tone ringer.

15

16

17

18

C4

C3

C2

C1

Keypad Columns

Keypad column inputs.

19

20

21

22

R4

R3

R2

R1

Keypad Rows

Keypad rows. These pins are also used to determine the operating mode.

23

24

M2

M1

Microphone Inputs

Input for electret microphone.

25

CI

Complex Impedance and AC Impedance Input

Placing 47Kohm resistor between CI and AGND pins sets the AC impedance

around 600ohm. The higher the resistor the higher the AC impedance. Lower

resistor results in lower AC impedance.

26

RXO

Receive Output

These outputs drive a dynamic earpiece.

27

RXI

Receive Input

Input for received signal.

28

STB

Side Tone Balance Input

Side tone cancellation input.