XECOM XE2420 Datasheet

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XE2420

March 2002

2400 BPS Surface-Mountable Integrated Sealed-Hybrid Modem

Description

Xecom’s XE2420 provides a complete 2400 BPS modem into an inexpensive miniature, surface-mount package. Xecom’s new HyPLCC™ package (Hybrid PLCC) makes it possible to meet the conflicting goals of small size, low cost and surface-mountability. The XE2420 targets remote monitoring applications in industrial, commercial and residential locations

As a complete modem, the XE2420 includes not only all modem circuitry but also user transferrable FCC Part 68 Registration and UL60950 recognition. This allows the XE2420 to be safely integrated into your embedded application.

Xecom’s new HyPLCC™ package infuses the XE2420 with both its small size and surface mountability. The HyPLCC package allows complex hybrid circuits to fit the 68-Pin PLCC footprint. The HyPLCC™ package provides a completely sealed enviroment protecting the XE2420 during assembly and board cleaning operations.

Features

*Small Size: The HyPLCC™ measures less than 1 inch by 1inch square and 0.290 inches thick

*Surface-mountabile: The HyPLCC™ package is equivalent to a 68-Pin PLCC device.

*Data transfer at 2400, 1200 and 300 BPS using V.22bis, V.22, V.23, V.21, Bell 202, Bell 212A, and Bell 103 Protocols

*Modem Control and Configuration via industry standard AT Commands.

*Supports external shared line features permitting unobtrusive sharing of a local telephone line.

*Complete integrated DAA includes, Ring Detect, Loop Current Holding Circuit, Hook Switch. Metalic Surge Protection, and Telephone Line Transformer

*User Transferrable FCC Part 68 Registration

*UL60950 Recognition

*Low Power operation, 330 milliWatt; Power down operation less than 1 microWatt

XE2420 BLOCK DIAGRAM

XECOM

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XE2420

XE2420 Mechanical Specifications

b c

a

d

i

i

 

f

(TOP)

 

g

 

e

e

c

 

 

 

 

 

.050”

45O

i

 

 

Inches

 

 

Millimeters

 

Dimension

Min

Typ

Max

Min

Typ

Max

a

0.280

0.285

0.290

7.11

7.24

7.37

b

0.985

0.990

0.995

25.02

25.15

25.27

c

0.950

0.955

0.960

24.13

24.26

24.38

d

0.910

0.920

0.930

23.11

23.37

23.62

e

0.045

0.050

0.055

1.15

1.27

1.40

f

0.695

0.700

0.705

17.65

17.78

17.91

g

0.395

0.400

0.405

10.03

10.16

10.29

i(radius)

0.015

0.020

0.025

0.13

0.25

0.38

 

 

 

 

 

 

 

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XE2420

XE2420 Pin Configuration

/DCD 1 /CTS 2 RESET 3 /DSR 4 /RTS 5 /DTR 6 /RXD 7 /TXD 8 /RI 9 GND 10 N/C 11 EECL 12 EEDT 13 Vcc 14

Vui 15

TOP

24 RING

23 N/C

22 TIP

21 N/C

20 N/C

19 HI3

18 HI1

17 CD

16 HI2

Pin Descriptions

PIN

NAME

DESCRIPTION

1

/DCD

/DCD is an active low output from the modem. The AT&C command controls when the

 

 

XE2420 asserts /DCD.

2

/CTS

/CTS is an active low output from the modem. The modem asserts /CTS to indicate that it can

 

 

accept data from the terminal equipment on /TXD.

3

RESET

RESET is an active high input which intiates a modem hardware reset. RESET must be active

 

 

for a minimum of 100 milliseconds for a proper modem reset sequence. No external reset is

 

 

required; if none is used the RESET signal should be left open.

4

/DSR

/DSR is an active low output from the modem. The AT&S command controls when the XE2420

 

 

asserts /DSR.

5

/RTS

/RTS is an active low input to the modem. /RTS indicates to the modem that the host has data

 

 

to send.

6

/DTR

/DTR is an active low input to the modem. The AT&D command determines how the modem

 

 

will interpret activity on /DTR.

7

/RXD

/RXD provides the path for received data and modem responses to be sent from the modem to

 

 

the host terminal equipment.

 

 

 

 

 

 

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XE2420

XE2420 Pin Descriptions (continued)

PIN

NAME

DESCRIPTION

8

/TXD

/TXD provides the path for transmitted data and modem commands to be passed from the host

 

 

terminal equipment to the modem.

9

/RI

The /RI signal reports on the presence of an incoming ring signal. When a ring occurs across

 

 

Tip and Ring, the /RI output toggles at the ring frequency. The /RI output is powered by Vui

 

 

and therefore operates even when VCC is removed from the modem.

10

Ground

Ground provides the reference voltage for all host interface signals.

11

N/C

No internal connection

12

EECL

EECL provides the clock to the optional external non-volatile memory. The XE2420 requires

 

 

a serial 8 by 256 Byte EEPROM for telephone number storage. If the non-volatile memory is

 

 

not used, EECL should remain unconnected.

13

EEDT

EEDT provides the serial data connection for the optional, external non-volatile memory. The

 

 

XE2420 requires a serial 8 by 256 Byte EEPROM for telephone number storage. If the non-

 

 

volatile memory is not used, EEDT should remain unconnected.

14

VCC

VCC provides 5 volt power to the modem. The RI output is not powered by VCC but by Vui.

15

Vui

Vui provides uninterrupted power to the XE2420 ring detect circuit. Placing 5 volt power on

 

 

Vui insures that the /RI ouput will operate when VCC is removed from the modem.

16

HI2

HI2 is one of the four hardware hooks for connecting shared line features to the XE2420.

 

 

HI2 interfaces to the 911 Interrupt circuit. This circuit detects changes in the loop current

 

 

when an extension handset is lifted as when making an emergency call. The system host

 

 

should immediately abort the modem connection to permit the user to complete their call.

 

 

See the Application Note on Page 10 of this data sheet to see how these line monitoring

 

 

circuits interface with the XE2420.

17

CD

CD provides another of the four hardware hooks for connecting shared line features to the

 

 

XE2420. CD interfaces to the Connect Dectect circuit. Connect Detect allows the system

 

 

host to check the status of the telephone line before going off-hook to initiate a call. If the

 

 

phone line is in use,the host can delay its call until the telephone line is free. See the

 

 

Application Note on Page 10 of this data sheet to see how these line monitoring circuits

 

 

interface with the XE2420.

18

HI1

HI1 is one of the four hardware hooks for connecting shared line features to the XE2420.

 

 

HI1 interfaces to the 911 Interrupt circuit. This circuit detects changes in the loop current

 

 

when an extension handset is lifted as when making an emergency call. The system host

should immediately abort the modem connection to permit the user to complete their call. See the Application Note on Page 9 of this data sheet to see how these line monitoring circuits interface with the XE2420.

XECOM

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XE2420

XE2420 Pin Descriptions (continued)

PIN

NAME

DESCRIPTION

19

HI3

HI3 is one of the four hardware hooks for connecting shared line features to the XE2420.

 

 

HI3 interfaces to the 911 Interrupt circuit. This circuit detects changes in the loop current

 

 

when an extension handset is lifted as when making an emergency call. The system host

 

 

should immediately abort the modem connection to permit the user to complete their call.

 

 

See the Application Note on Page 10 of this data sheet to see how these line monitoring

 

 

circuits interface with the XE2420.

20

N/C

No internal connection, To prevent damage in case of voltage surges on the telephone line, we

 

 

recommend that nothing be connected to this pin.

21

N/C

No internal connection, To prevent damage in case of voltage surges on the telephone line, we

 

 

recommend that nothing be connected to this pin.

22

Tip

The Ring and Tip signals provide modem the connection to the telephone line. FCC Part 68

 

 

Rules require a 1500 volt isolation barrier between the telephone line and all other circuits.

 

 

This isolation must be preserved throughout the system.

 

 

The telephone company places a DC “Battery” voltage across Tip and Ring on all public switched

 

 

telephone lines. The XE2420 will operate regardless of the polarity of this “Battery” voltage.

 

 

The “Battery” voltage drives up to 100 milliamps of DC loop current.

 

 

UL60950 requires minimum creepage and clearances distances be maintained between the

 

 

Tip and Ring traces and all other circuits. Clearance is the shortest distance between conductive

 

 

circuits; creepage is the distance between conductive surfaces along the surface

23

N/C

No internal connection, To prevent damage in case of voltage surges on the telephone line, we

 

 

recommend that nothing be connected to this pin.

24

Ring

The Ring and Tip signals provide modem the connection to the telephone line. FCC Part 68

 

 

Rules require a 1500 volt isolation barrier between the telephone line and all other circuits.

 

 

This isolation must be preserved throughout the system.

The telephone company places a DC “Battery” voltage across Tip and Ring on all public switched telephone lines. The XE2420 will operate regardless of the polarity of this “Battery” voltage. The “Battery” voltage drives up to 100 milliamps of DC loop current.

UL60950 requires minimum creepage and clearances distances be maintained between the Tip and Ring traces and all other circuits. Clearance is the shortest distance between conductive circuits; creepage is the distance between conductive surfaces along the surface.

XECOM

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XE2420

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