SM8223A

NIPPON PRECISION CIRCUITS—3

PIN DESCRIPTION

Number

Name

I/O

Function

P ad dimensions (

µm)

XY

1

TIP

I

Tip input. Connected to the telephone line through a protection circuit

1046

2934

2

RING

I

Ring input. Connected to the telephone line through a protection circuit

6 3 8

2934

3G S

O

Input-stage amplifier gain-select output. Used to adjust the gain of the input-

stage amplifier.

176

2665

4

A G N D

O

1 7 6

1954

5

RDIN

I

Ring detector input. Used for line reversal and ring signal detection.

Connected for ring detection of attenuated ring signals.

176

1534

6

RDRC

I/O

Ring detector RC terminal. Connected to an RC network which sets the ring

detector delay time.

176

492

7

RDET

O

Ring detector output. RDRC -input Schmitt-trigger buffer output. L OW -level

output when ring signal is detected.

596

226

8P D W N

I

P ow er-down control input. L OW -level for normal operation. HIGH-level for

p ow er-down state. In the pow er-down state, pins AG N D , OSCOUT, DOUT,

and D V are HIGH.

1063

226

9

G N D

–

Ground. Connected to the system ground potential.

1634

226

1 0

OSCOUT

O

Cr ystal oscillator output. The cr ystal oscillator element is connected between

this pin and OSCIN.

2053

226

1 1

OSCIN

I

Cr ystal oscillator input. The cr ystal oscillator element is connected between

this pin and OSCOUT.

2634

506

1 2

IC

I

Test input. Tied LOW for normal operation.

2634

1550

13

FSK/ DTMF

O

FSK/DTMF discr iminator output. HIGH-level output when receiving FSK

signal, and LOW -level output when receiving DTMF signal.

2634

1942

1 4

DOUT

O

Demodulator output. Demodulated FSK or DTMF signal output. HIGH-level

output in pow er-down state.

2634

2623

15

D V

O

Data trigger output. Data is output on DOUT when this pin goes LOW .

2211

2934

1 6

V D D

–

Supply

1612

2934