XECOM XEV90-ITR, XEV90 Datasheet

XECOM XEV90

56 KBPS DAA in a PLCC Package

XEV90

7-99

Figure 1: XEV90 BLOCK DIAGRAM

Line Trans-

former

Line Current

Holding Cir-

cuit

Hookswitch

Ring De-

tector

T1

T2

OH(+)

RI(+)

Tip

Ring

Low

Impedance

Dialing

MUTE

L1
L2

Billing Tone

Filter

(Optional)

Description

Xecom’s XEV90 is a complete DAA integrated into a
compact PLCC package. The XEV90 supports analog
data transfer to 56 KBPS. The 68-Pin PLCC package
permits automated, high-volume assembly.

The XEV90 does not sacrifice performance for small size
and surface-mount convenience. The heart of the XEV90
is a proprietary, low profile, low distortion transformer.
This wide bandwidth, low distortion device provides the
clear signal path required for 56 KBPS analog data
transfer.

Like all Xecom DAA's the XEV90 is a complete
telephone line interface. It includes the telephone line
transformer, line current holding circuit, hookswitch and
ring indicator. The XEV90 replaces the dozens of
components found in a discrete DAA design.

Features

* Package: 68-Pin PLCC (only 18 pins used)

dimensions 0.952 inches by 0.952 inches by 0.170
inches high

* Meets Total Harmonic Distortion requirements for

reliable 56 Kbps modems (-85 dB typical);

* Integrated Low-Distortion T elephone Line

Transformer

* Integrated Ring Detection with active high and

active low ouput signals

* Operates on either a single Power Supply of +5 or

+ 3 Volts;

* Solid-State Hookswitch Control with active high

and active low inputs;
* FCC Part 68 Compliant;
* Extended Temperature Range available;

OH(-)

RI(-)

DC2
DC1

XECOM (2) XEV90

Figure 2: XEV90 Pin Configuration

1
2
3
4
5
6
7
8
9

18
17
16
15
14
13
12
11
10

RI(-)
RI(+)
OH(+)
T1
T2
/Mute
OH(-)
VCC
Gnd

N/C

Ring

Tip

N/C

L2
L1

N/C
DC1
DC2

XEV90

(top)

Pin Descriptions

PIN NAME DESCRIPTION

1 N/C No Connection
2 Ring Ring is one wire of the two-wire telephone line connection (RJ11 Pin 4). 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. Xecom recommends 0.100 inch spacing between traces connected to
Ring and all other conductors to preserve this isolation.

3 Tip Tip is one wire of the two-wire telephone line connection (RJ11 Pin 3). The telephone company places

a DC "Battery" voltage across Tip and Ring on all public switched telephone lines. The XEV90 accepts
this line battery voltage without regard to its polarity.

4 N/C No Connection

5, 6 L1 & L2 L1 and L2 provide the connective points for a billing tone filter when required.

7 N/C No Connection

8, 9 DC1 & DC2 DC1 and DC2 control performance of the line current holding circuit. A jumper from DC1 to DC2

limits DC loop current to 60 milliamps. An open circuit between DC1 and DC2 permits loop currents up
to 100 milliamps as required for North America. A resistor may be placed between DC1 and DC2 to
alter the off-hook impedence to meet unique country requirements.

10 GND Ground connection to the XEV90. This signal provides the reference for the OH output and RI input.

This pin should be connected to the systems digital ground.
11 VCC +5 Volt power source for the XEV90. VCC powers the RI and OH control lines.
12 OH(-) Modem switch-hook control: OH(-), an active low input, for controls the switch hook in the XEV90.

When the host activates pin 12, the switch-hook closes and the XEV90 seizes the local telephone line.

Pin 16 provides an active high switch-hook control. OH(-) should remian open when using OH(+).

The host can pulse OH(-) line to perform rotary dialing. The normal pulse rate is ten pulses per second.

Closing the switch-hook creates a series of pulses. Dial one pulse for the digit one to ten pulses for the

digit zero. The pulses on OH(-) must be asymmetrical, active for thirty-one milliseconds, inactive for

sixty-nine milliseconds. An inter-digit delay of at least one hundred milliseconds is required.

Pin Descriptions

PIN NAME DESCRIPTION

13 Mute The Mute signal can be used for pulse (rotary) dialing. The host must toggle the Mute signal to generate

the dialing pulses.
14 T2 T2 in conjunction with T1 provides the differential input/output for the analog signal. T2 connects

directly to the secondary side of the miniature line transformer embedded into the XEV90. T o match the

impedance of the DAA to the 600 ohm telephone line, a 320 ohm resistor must be connected in series

with T1 or T2.
15 T1 T1 in conjunction with T2 provides the differential input/output for the analog signal. T1 connects

directly to the secondary side of the miniature line transformer embedded into the XEV90. T o match the

impedance of the DAA to the 600 ohm telephone line, a 320 ohm resistor must be connected in series

with T1 or T2.
16 OH(+) Switch-hook control to the modem. OH(+) provides an active high input for controlling the switch

hook. When pin 16 is active, the switch-hook closes and the XEV90 seizes the local telephone line.

OH(+) should remain open when using OH(-).

The host can pulse OH(+) line to perform rotary dialing. The normal pulse rate is ten pulses per second.

Closing the switch-hook creates these pulses. Dial one pulse for the digit one to ten pulses for the digit

zero. The pulses on OH(+) must be asymmetrical, active for thirty-one milliseconds, inactive for sixty-

nine milliseconds. An inter-digit delay of at least one hundred milliseconds is required.
17 RI(+) Ring Indicate output from the modem. RI(+) is an active high, open-emmitter output. RI(+) provides

a square wave representation of the Ring signal present across Tip and Ring. This permits intelligent

monitoring of the incoming ring. The XEV90 recognizes ring voltages of thirty-eight to one hundred

fifty volts RMS in the frequency range of sixteen to sixty-eight Hertz. When using the RI(+) output,

a 20 Kohm pull-down resistor must be added to RI(+); RI(-) must be tied to VCC.
18 RI(-) Ring Indicate output from the modem. RI(-) is an active low, open collector output. RI(-) provides

a square wave representation of the Ring signal present across Tip and Ring. This permits intelli-

gent monitoring of the incoming ring. The XEV90 recognizes ring voltages of thirty-eight to one

hundred fifty volts RMS in the frequency range of sixteen to sixty-eight Hertz. Pin 17 provides an

active high ring indication. When using the RI(-) output, a 20 Kohm pull-up resistor must be added

to RI(-); RI(+) must be tied to ground.

XECOM (3) XEV90