XECOM XE1276A Datasheet

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.

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.

Block Diagram

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

• 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)

PIN CONFIGURATION

TST

N/C N/C

/DCD

/DTR

D/V

OHO

RXD

TXD

N/C

SPK

1 18 2 17 3 16 4 5 6

XE1276A

(Top View)

8 9 10 11 12 13

RI GND VCC

RING 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.

XECOM (2) 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.

XECOM (3) XE1276A

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