V2.5 April 2004
Data Sheet
Silver
TELECOM
Ag1110
LOW COST SLIC
FEATURES
•
Single-in-line (SIL) PBX SLIC with integral
lead frame.
TIP
RIN
V
IN
V
OUT
• Highly integrated, requiring a minimum of
external components.
• Constant current feed to the line, with
constant voltage fold over.
• Single +5V system side power supply.
Control and
Supervision
• 16mA minimum loop current into 2000R
loop (including telephone set).
• 600R and 900R impedance options.
• Works with a battery of up to –72V.
PBX
SLIC
Figure 1: Single Channel SLIC
• Low idle power operation (20mW).
• Short circuit protection.
•
Loop open function - loop off under logic
control.
DESCRIPTION
The Silver Telecom Ag1110 comprises a
single Subscriber Line Interface Circuit (SLIC)
in a single-in-line (SIL) 13 pin format. The
combination of features and packaging offers
extremely efficient use of board area, saving
significant system size and cost.
The SLIC is highly featured requiring a
minimum of external components. Functions
such as a relay driver, are provided on board
along with precision loop feed resistors.
• On hook transmission.
The Ag1110 has been designed to work in
private systems where cost is a major
concern and advanced public network
signalling is not a requirement.
The system interface has been designed for
direct connection to popular codecs for both
audio and signalling.
The Ag1110 is ideal for any application where
high-density line interfacing is required, such
as Computer Telephony Integration (CTI),
Small Office Home Office (SOHO) and PABX.
© Silver Telecom 2004
V2.5 April 2004
Data Sheet
Ag1110
LOW COST PBX SLIC
Ag1110
1
Figure 2: Packaging Format
V
BAT
V
CC
GND
TC
TIP
RING
2-4 Wire
Converter
Line
Interface
V
OUT
V
IN
SHK
Supervision
RT
Power
Management
Relay
Driver
I
loop
Control
LO
RDO
RDI
Figure 3: Functional block diagram
© Silver Telecom 2004
V2.5 April 2004
Data Sheet
Ag1110
LOW COST PBX SLIC
Description
Ring.
Connects to the subscriber line Ring through the n/c pole of the ringing relay.
Tip.
Connects to the subscriber Tip.
Tip Clamp.
A diode must be connected externally between TC and Tip to conduct
ringing current.
Ring Trip.
A capacitor is connected externally between RT and GND to filter out the AC
component of the ringing signal. Must be switched out during LD dialling.
Analog Ground.
Normally connected to system ground.
Audio In.
This is the analog input signal from the codec (which is output on Tip and
Ring).
+5V Positive Supply.
This pin must be connected to +5V.
Audio Out.
This is the analog output signal (from Tip and Ring) to the codec.
Battery Voltage.
The negative supply rail. Typically -48V.
Switch Hook Current.
Indicates loop current is flowing (such as when off hook) when at
logic 1.
Loop Off.
A logic 1 removes loop current, used during fault conditions.
Relay Driver Input.
A logic 1 activates RDO.
Relay Driver Output.
Open collector relay driver, connects to the coil of the ringing
relay.
Pin Description
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
Name
RING
TIP
TC
RT
GND
V
IN
V
CC
V
OUT
V
BAT
SHK
LO
RDI
RDO
RING
TIP
TC
RT
GND
V
IN
V
CC
V
OUT
V
BAT
SHK
LO
RDI
RDO
1
2
3
4
5
6
7
8
9
10
11
12
13
Figure 4: Pin Connections
© Silver Telecom 2004
V2.5 April 2004
Data Sheet
Ag1110
LOW COST PBX SLIC
1.0 Line Interfacing
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.
2.1 Transmit and Receive Gain.
The gain in both the transmit direction (TIP/RING to
V
OUT
) and the receive direction (V
IN
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).
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.
2.3 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.
.
2.0 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 V
OUT
and
from a ground referenced input at V
IN
.
V
OUT
and V
IN
are normally connected to a Codec for
conversion to and from a digital Pulse Code Modulated
(PCM) stream.
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 V
IN
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
V2.5 April 2004
Data Sheet
+5V
C1
D1
K1
Ag1110
LOW COST PBX SLIC
0V
-48V
R2
90Vrms
V
CC
RDO
R1
To MCU
TEXAS
0GSX
TCM38C17
0ANLGIN-
0PWRO+
1GSX
1ANLGIN
-
1PWRO+
2GSX
2ANLGIN
2PWRO+
-
3GSX
3ANLGIN
-
3PWRO+
SHK
RDI
LO
Ag1110
D2
RING
R3
RING
C3
V
OUT
V
IN
C4
Silver
TE LEC OM
D3
-V
BAT
D5
TIP
R5
R4
TIP
D6
D4
TC
RT
C6
0V
+
GND
C2
V
BAT
Components
R1 = 300R, 2W (only one needed per linecard)
R2 = PTC eg. Walsin PTD3A220H14 (one needed per
system)
R3, R4 = 25R and 350mA fuse (eg. Bussman C515)
R5 = 20k, 1/4W. Only fitted for on hook transmission
C1, C2 = 100nF, 50V, ceramic
C3, C4 = 100nF, 50V, ceramic
C6 = 1uF electrolytic
D1 = 1N4148
D2-D6 = 1N4003
K1 = Relay, 5V (or 6V), 1 form C, 120R Coil (e.g. Omron
G2E 184P-H or HKE HRS1H)
-48V
Figure 5: Ringing Application Diagram with Codec
The Ag1110 will provide on hook transmission with a
high impedance on Tip/Ring or where specific loads
are demanded by Network Operators.
a fly back diode being fitted across the coil. Normally
the ringing generator is cadenced, and the ringing relay
will only be activated during the off period, as this
prolongs the life of the relay contacts.
3.0
Loop Current Detect Level
5.0
Protection
When the subscriber goes “off-hook”, loop current will
begin to flow. If this current is above the detection
threshold (default 10mA), the switch hook output, SHK,
will switch to a logic 1. It is recommended that
software or hardware de-bouncing of the switch hook
signal is used, to avoid short pulses due to contact
bounce, causing a false switch hook output triggering
the incorrect system response.
During loop disconnect (pulse) dialling, SHK will pulse
between logic 1 and logic 0 to indicate the digits being
dialled. Again it is recommended that software de-
bouncing is used to avoid false detection of digits.
In most ‘off-premise’ applications the subscriber circuit
will be required to withstand over voltage conditions
which could be caused by lightning or overhead power
cables striking the telephone cables. It is therefore
normal to provide primary and secondary protection
circuits to prevent damage to the SLIC.
The Ag1110 has been designed to be able to use low
cost lightning and power cross protection components,
and a typical circuit is shown in Figure 5. This circuit
will meet UL1459 and 1950 requirements.
The series element (R3 and R4) is a combination of a
fuse (e.g. 350mA, Bussman C515 or Littlefuse
220003), and a surge resistor (25R typically).
Alternatively a Teccor F1250T or F0500T fuse may be
used without a surge resistor. The lightning protection
is provided by diodes connected to 0V, and the battery
voltage. To prevent lightning surges propagating via
V
BAT
, this should be clamped with a Tranzorb device
4.0
Relay Driver
On the SLIC an open collector driver, RDO, is provided
to drive the ringing relay. This is activated by
connecting a logic 1 to RDI. The coil of the user
provided ringing relay must be connected between
RDO and a positive supply voltage (normally +5V), with
© Silver Telecom 2004
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