73M223

1200 Baud FSK Modem

3

PIN DESCRIPTION

PIN NO.

PIN NAME

DESCRIPTION

1

VDD

Positive Supply Voltage. Bypasses to Vss with 0.1 µF capacitor.

2

RXA

Receive Analog Input. Analog input from the telephone network.

3

CAP

Capacitor. Connect a 0.1µF capacitor between Pin 3 and ground (VSS).

4

RXF

Filtered Receive Analog Input

5

FIL

Analog Input Control. A logical 1 selects the filtered input. A logical 0 selects

the non-filtered input.

6

TEST

Self-Test Mode Control. Normal operation when a logical 0.A logical 1 places

the device into the self-test mode. A low appears at RXD, to indicate a

properly functioning device.

7

7;

Transmitter Control. A logical 0 selects transmit mode. A logical 1 selects a

stand-by condition forcing TXA to VDD/2 VDC.

8

VSS

Ground

9

SYNC

Synchronous Clock Output. Digital output synchronized with the 1200 bit/s

received data when

6<1 LV ORZ and used to sample the received data or eye

pattern. The falling edge of SYNC should be used to sample RXD. When

6<1

LV KLJKD 1200 H] FORFN LV RXWSXW

10

6<1

Sync Enable. A logic 0 locks the SYNC clock PLL to the 1200 baud receive

data. A logic 1 disables the receive data PLL, and connects SYNC to the 1200

HZ reference.

11

RXD

Receiver Digital Output

12

TXD

Transmitter Digital Input

13

Crystal Input (3.1872 MHz) or External Clock Input

14

Crystal Return

15

CLK

1200 Hz Square wave Output. Can drive up to 10 CMOS loads.

16

TXA

Transmitter Analog Output

ELECTRICAL SPECIFICATIONS

Recommended conditions apply unless otherwise specified.

ABSOLUTE MAXIMUM RATINGS

Operation outside these rating limits may cause permanent damage to this device.

PARAMETER

RATING

Power Supply Voltage (VDD-VSS)

14 V

Analog Input Voltage at RXA

- 0.3 to VDD V

Analog Input Voltage at RXF

- 3 to VDD V

Digital Input Voltage

VSS – 0.3 to VDD + 0.3 V

Storage Temperature Range

- 65 to + 150

°C

Operating Temperature Range

- 25 to + 70

°C

Lead Temperature (10 secs soldering)

260

°C