AG1110 데이터 시트보기 (PDF) - Unspecified

부품명

상세내역

제조사

AG1110

LOW COST SLIC

Unspecified 

V2.5 April 2004

Data Sheet

1.0 Line Interfacing

Ag1110

LOW COST PBX SLIC

2.1 Transmit and Receive Gain.

As well as being in an electrically demanding

environment, the needs of different applications and

regulatory standards means that the SLIC must allow

flexibility, together with facilities to ensure robust

performance. The Ag1110 SLIC provides a complete

and flexible interface to the telephone line.

1.1 Battery Feed

The battery feed to the telephone line used by the

Ag1110 can vary between -42V and -72V. For public

network applications -48V is the most common. A

constant current is fed to the line, which is preset to

25mA.

If the loop length is such that the constant current feed

cannot be maintained, then the Ag1110 will revert to a

constant voltage source, allowing the loop to be

serviced at a reduced loop current. Typically with a

2000R loop, and -48V battery voltage, loop current is

18.5mA.

The power dissipated in the Ag1110 SLIC is internally

limited to a safe value.

1.3 Ringing

The ringing signal is provided by an external ringing

generator and is switched onto the line by the user

provided ringing relay. The coil of the ringing relay

should be connected to a positive supply voltage

(normally +5V) and the open collector driver RDO. The

relay is activated by applying a logic high to RDI. Note:

a flyback diode must be connected across the coil.

Unbalanced ringing is supported on the Ag1110 via the

use of a single external relay (with single pole

changeover). An application drawing is shown in Fig 5.

When the “off-hook” condition occurs during ringing (as

indicated when SHK produces a logic level 1), a logic

level 0 should be applied to RDI. This will deactivate

the relay, and remove the ringing signal from the line.

The SLIC will then assume it’s constant current feed

condition.

.

2.0 The 2-4 Wire (hybrid) Conversion.

This is also referred to as the hybrid function. The

Ag1110 transmits and receives balanced 2-wire analog

signals at the Tip and Ring connections. These are

converted to a ground referenced output at VOUT and

from a ground referenced input at VIN.

VOUT and VIN are normally connected to a Codec for

conversion to and from a digital Pulse Code Modulated

(PCM) stream.

The gain in both the transmit direction (TIP/RING to

VOUT) and the receive direction (VIN to TIP/RING) is set

to -1dB. Normally any gain adjustments required by

the user can be made by using the Codec.

2.2 The 2 Wire Impedance.

The input impedance, Zin, of the Ag1110 SLIC is set to

600R. For countries where the line impedance is 600R

e.g. North America and the Far East, no external

adjustment is required. For countries where an

alternative line impedance is used the Codec filter

characteristics can be programmed to give the required

matching. For countries where the impedance is 900R,

the Ag1110-900 can be used where the SLIC

impedance is internally fixed at 900R.

The Codec manufacturer will provide information on

how Codec programming is accomplished.

Programmable Codecs require information about the

transfer characteristics of the SLIC with which they are

working, which is contained in a “.CIR” netlist. A “.CIR”

netlist can be obtained by contacting either Silver

Telecom or your local representative, to allow the

Codec programming coefficients to be generated.

If a simple Codec is being used, the Ag1110 can only

accommodate countries where the line impedance is

600R (Ag1110), or 900R (Ag1110-900).

2.3 Network Balance Impedance.

The network balance impedance, Zb, is set to 600R for

the Ag1110. For countries where the network balance

impedance is 600R e.g. North America and the Far

East, no external adjustment is required. For 900R

balance the Ag1110-900 can be used. For countries

where an alternative network balance impedance is

used the Codec filter characteristics can be

programmed to give the required matching. The “.CIR”

netlist is again needed to allow the Codec

programming coefficients to be generated.

If a simple Codec is being used the Ag1110 can only

accommodate countries where the line impedance is

600R or 900R.

2.5 On Hook Transmission.

The Ag1110 is capable of on-hook transmission with

the addition of a 20k, 0.25W resistor from Tip to Ring.

This means analog signals can be transmitted from VIN

through Tip and Ring and onto the line even when no

loop current is flowing. This can be used when

sending Caller Line Identification (CLI) information or

for other “no ring” calls. With the tip-ring resistor fitted,

idle current increases by 2.2mA.

© Silver Telecom 2004

Share Link: