XECOM XE1276A Datasheet

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xecom

XE1276A

2/97

Compact 1200 bps Modem

Description

The XE1276A is the successor to the XE1276. Several improvements have been incorporated in the XE1276A. Power consumption has been reduced, an automatic Sleep mode has been added and the XE1276A includes non-volatile memory for storage of the "AT" Commands used for modem control and configuration.

Features

Modem Protocols Supported: V.22, V.21, Bell 212A and 103

Pin compatible with the XE1276, XE2476 and CH1776

Command set: "AT" command set for modem control and configuration.

Modem Configuration stored in NVRAM

The XE1276A provides a replacement for the CH1776. Most OEM's currently using the CH1776 can use the XE1276A without altering their existing hardware or software. The XE2476 provides a 2400 bps upgrade in the same package design.

The XE1276A includes user transferable FCC Part 68 registration. This permits use of the XE1276A without additional FCC Part 68 testing.

Small Size: 2.00 inches long, 1.125 inches wide, 0.44 inches high.

Single +5V supply

Low power CMOS: Operating: 200 mW (Typical) Sleep: 50 mW (maximum)

Block Diagram

PIN CONFIGURATION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TST

 

1

18

 

RI

 

 

 

N/C

 

2

17

 

GND

 

 

 

N/C

 

3

16

 

VCC

 

 

 

/DCD

 

4

 

 

 

 

 

 

/DTR

 

5

 

 

 

 

 

 

D/V

 

6

XE1276A

 

 

 

 

 

OHO

 

7

 

 

 

 

 

 

(Top View)

 

 

 

 

 

RXD

 

8

 

 

 

 

 

 

 

 

 

 

 

 

TXD

 

9

 

 

 

 

 

 

N/C

 

10

 

 

 

 

 

 

SPK

 

11

 

 

 

 

 

 

VO

 

12

 

 

 

 

 

 

VI

 

13

 

 

 

 

 

 

 

 

 

15

 

RING

 

 

 

 

 

 

14

 

TIP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

XE1276A Mechanical Specifications

 

INCHES

METRIC(MM)

 

 

 

 

 

PIN

MIN

MAX

MIN

MAX

A

1.990

2.010

50.55

51.05

B

1.115

1.135

28.32

28.83

C

0.420

0.430

10.67

10.92

D

0.100

0.120

2.54

3.05

E

0.890

0.910

22.61

23.11

F

0.090

0.110

2.29

2.79

G

0.090

0.110

2.29

2.79

H

0.190

0.210

4.83

5.33

I

0.020

0.025

0.51

0.64

J

0.125

0.200

3.18

5.08

 

 

 

 

 

Pins = 0.025 square pin recommended hole size 0.056"

ABSOLUTE MAXIMUM RATINGS*

SUPPLY VOLTAGE - Vcc

+6.5 Volts

DC INPUT VOLTAGE

-0.6 Volts to +6.5 Volts

STORAGE TEMPERATURE RANGE

-25° C TO +100° C

LEAD TEMPERATURE (Soldering, 2 sec per wave)

260° C

OPERATING TEMPERATURE RANGE

0 TO 70° C

*Exceeding these values may result in permanent damage to the device.

Power Supply Characteristics(TA = 0 - 70°C, Vcc = 5v ±5%)

 

Symbol

Parameter

Min

Typ

Max

Units

Comments

 

 

Vcc

Supply Voltage

4.75

5.0

5.25

V

 

 

 

Icc

Vcc Supply Current

 

40

50

mA

On-Line All outputs

 

 

 

 

 

 

 

 

Disconnected

 

 

Icc

Vcc Supply Current

 

7

10

mA

Sleep Mode

 

 

 

 

 

 

 

 

 

 

Sleep Mode: The XE1276A has an integrated, advanced power management capability. If no activity is detected on the RXD, DTR, or RI lines the modem will automatically go into a smart power down mode. In this mode power consumption is less than 50 milliwatts.

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XE1276A

Pin Descriptions

PIN NAME

DESCRIPTION

 

 

1

TST

This output is for Xecom test purposes only;

 

 

2

N/C

No Connection

 

 

3

N/C

No Connection

 

 

4

\DCD

DCD, Data Carrier Detect, is an active low output from the modem. DCD goes low to

 

 

 

indicate receipt of a valid carrier signal.

 

 

5

\DTR

DTR, Data Terminal Ready, is an active low input to the modem. DTR must be present for

 

 

 

the XE1276A to remain on line. If DTR goes high while the modem is on line, the modem

 

 

 

disconnects immediately. The XE1276A will not automatically answer an icoming call if DTR

 

 

 

is not active.

 

 

6

D/V

The D/V, Data/Voice, output can be used to drive a relay to connect an auxiliary telephone

 

 

 

handset. D/V is high when the modem is off-hook And low when the modem is on-hook.

 

7

OH

OH, Off-Hook, is an active high output which indicates that the XE1276A is connected to the

 

 

 

telephone line.

 

 

8

RXD

RXD, Received Data, provides the serial data output path from the modem.

A logic "high"

 

 

 

represents a "mark" and a logic "low" represents a "space".

 

 

9

TXD

TXD, Transmit Data, provides the serial data input path from the host.

A logic "high"

 

 

 

represents a "mark" and a low represents a"space", TTL.

 

 

10

N/C

No Connection

 

 

11

SPK

SPK, Speaker, provides the Audio output to the modem speaker. Speaker operation is

 

 

 

determined by the ATL and ATMM commands . This output can drive a 300 ohm load.

 

12

VO

The Modem Line Interface permits placement of non-modem signals on the telephone line

 

 

 

through the modem's telephone interface. VO must be tied to VI for normal modem operation

 

 

 

and open to place non-modem signals on the line through VI.

 

 

13

VI

VI, Voice Interface, provides a path for non-modem signals to be placed on the telephone line

 

 

 

through the modem's telephone interface. VI must be tied to VO for modem operation.

 

14

TIP

Tip connection to the phone line(RJ11 pin3) from the internal DAA.

 

 

15

RING

Ring connection to the phone line(RJ11 pin4) from the internal DAA.

 

 

16

Vcc

+5 Volt power for the modem.

 

 

17

GND

Ground reference for the modem.

 

 

18

RI

RI, Ring Indicator, provides an active high output whenever a ring signal appears on the

 

 

 

telephone line.

 

 

 

 

 

 

 

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XE1276A

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