ETC AG1110

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
VIN
PBX
SLIC
VOUT
• 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.
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.
© Silver Telecom 2004
• 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.
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
Ag1110
1
Figure 2: Packaging Format
VBAT
VCC GND
TC
RING
VOUT
2-4 Wire
Converter
TIP
VIN
Line
Interface
SHK
Supervision
RT
Power
Management
RDO
RDI
Relay
Driver
Iloop
Control
Figure 3: Functional block diagram
© Silver Telecom 2004
LO
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
Pin Description
Pin #
Name
Description
1
RING
2
TIP
3
TC
4
RT
5
GND
6
VIN
Audio In. This is the analog input signal from the codec (which is output on Tip and
Ring).
7
VCC
+5V Positive Supply. This pin must be connected to +5V.
8
VOUT
Audio Out. This is the analog output signal (from Tip and Ring) to the codec.
9
VBAT
Battery Voltage. The negative supply rail. Typically -48V.
10
SHK
Switch Hook Current. Indicates loop current is flowing (such as when off hook) when at
logic 1.
11
LO
Loop Off. A logic 1 removes loop current, used during fault conditions.
12
RDI
Relay Driver Input. A logic 1 activates RDO.
13
RDO
Relay Driver Output. Open collector relay driver, connects to the coil of the ringing
relay.
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.
RING
TIP
TC
RT
GND
VIN
VCC
VOUT
VBAT
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
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.
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.
1.1 Battery Feed
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 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.
© Silver Telecom 2004
2.2 The 2 Wire Impedance.
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.
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
+5V
0V
-48V
C1
D1
R2
90Vrms
K1
VCC
RDO
To MCU
R1
SHK
RDI
LO
TEXAS 0GSX
TCM38C17
Ag1110
D2
R3
RING
RING
C3
VOUT
0ANLGIN0PWRO+
1GSX
1ANLGIN
1PWRO+-
VIN
C4
Silver
TE LEC OM
D3
-V BAT
TIP
TC
2GSX
2ANLGIN
2PWRO+-
R5
D5
R4
TIP
D6
D4
3GSX
3ANLGIN
3PWRO+-
RT
C6
0V
+
GND
Components
V BAT
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)
C2
-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.
3.0
Loop Current Detect Level
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 debouncing is used to avoid false detection of digits.
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
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.
5.0
Protection
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
VBAT, this should be clamped with a Tranzorb device
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
(Motorola or Protek 1.5KE56A for -48V battery).
Alternatively, the steering diodes may be connected to
the Tranzorb clamp on its own. This avoids injecting
transients into VBAT.
6.0
A Typical Application.
The Ag1110 can interface to most Codecs, and is
shown in a typical application in Fig 5. The Codec
which has been chosen to illustrate the use of the
Ag1110 is the Texas Instruments TCM38C17 quad
device.
The TI device has no facilities for impedance matching
The
and is designed for low cost applications.
impedance matching functions are therefore provided
by the SLIC circuitry. Therefore to maintain a low
solution cost and high integration, no impedance
programming components are needed, and only 600R
applications can be accommodated (unless using the
Ag1110-900, where 900R impedances can be
achieved). Where other impedances are required, an
“intelligent” codec is required such as the Legerity
QSLAC, or the Siemens SICOFI.
Figure 5 shows the usual configuration when DTMF
(tone) dialling only is used. In this case C6 is
permanently connected. If using LD dialling (also
known as loop disconnect or pulse dialling), C6 must
be switched out during dialling. Fig 6 shows a typical
circuit which could be used in such circumstances.
RDI
Q1
R7
+
R6
C6
RT
C5
GND
R8
0V
R6 = 470k
C6 = 1uF electrolytic
R7, R8 = 10k
C5 = 10nF ceramic
Q1 = general purpose transistor (eg. BC846)
Figure 6: LD Dialling Application
© Silver Telecom 2004
The audio interface is extremely simple, requiring only
the d.c. blocking capacitors C3 and C4. Gains are
fixed, and therefore again no external components are
needed. NOTE: decoupling and noise suppression
components used by the TCM38C17 are not shown.
The appropriate TI data sheet should be consulted for
the correct configuration.
The switch hook detection output (SHK) from the
SLICs are passed to the microprocessor interface so
that they can then be processed as necessary by the
system software. Similarly the Ringing Relay Control
(RDI), and loop off (LO) controls are provided by the
controlling processor.
The ringing signal is provided by a central ringing
generator, through a current limiting resistor (only one
needed per line card). The PTC thermistor protects the
ringing generator against permanent short circuit. It
may not be necessary to fit a PTC where adequate
short circuit protection is already provided (eg. with
Power Dsine ringing generators).
See paragraph 1.3 for further details on ringing - a
ringing application diagram is shown in Fig 5.
6.1
Board Layout Considerations.
When laying out a circuit board, which uses the
Ag1110 it is recommended to keep all tracks as short
as possible, especially those carrying audio frequency
signals. Decoupling capacitors should be used on the
power supplies to remove unwanted noise.
The devices should be oriented to maximise the air
flow over the SLICs to remove heat. The board should
ideally arrange the SLICs in line with the natural air
flow creating a “chimney effect”.
Ag1110
V2.5 April 2004
Data Sheet
7.0
LOW COST PBX SLIC
Electrical Characteristics.
Absolute Maximum Ratings* - All Voltages are with respect to ground unless otherwise stated.
Parameter
Symbol
Min
Max
Units
1
DC Supply Voltage
VCC
-0.3
6
V
2
DC Battery Voltage
VBAT
0.3
-75
V
3
Relay Driver Voltage
VRDO
-0.3
15
V
4
Relay Driver Current
IDO
100
mA
5
Power Dissipation, Off Hook @
25°C
PSLIC
1.35
W
6
Storage Temperature
+85
°C
TS
-20
* Exceeding the above ratings may cause permanent damage to the product. Functional operation under these conditions is not implied.
Maximum ratings assume free air flow.
Recommended Operating Conditions* - All Voltages are with respect to ground unless otherwise stated.
Parameter
Symbol
Min
Typ
Max
Units
1
DC Supply Voltage
VCC
4.75
5.0
5.25
V
2
DC Battery Voltage
VBAT
-42
-48
-72
V
3
Relay Driver Voltage
VRDO
-0.3
5
15
V
4
Operating Temperature
TOp
0
25
70
°C
* Typical figures are at 25°C with nominal +5V supplies and are for design use only.
© Silver Telecom 2004
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
DC Electrical Characteristics*
Symbol
1
Supply Currents, On-hook
ICC
IBAT1
IBAT1
1.75
0.25
2.50
mA
Idle
Idle
20k Tip-Ring
2
Power Consumption, Onhook
PTOT
22
130
mW
Idle
20k Tip-Ring
3
Constant current feed to
line
27
mA
RLOOP‡= 1100R
RLOOP‡=2000R
RLOOP‡=2300R
4
Tip/Gnd or Ring/Gnd or
Tip&Ring/Gnd overcurrent
30
mA
VBAT= -48V
5
SHK:
Output Low Voltage
Output High Voltage
VOL
VOH
0.9
3.15
V
V
@0.4mA
@-0.4mA
SHK:
Output Low Voltage
Output High Voltage
VOL
VOH
0.4
3.5
V
V
@50uA
@-50uA
RDI, LO:
Input Low Voltage
Input High Voltage
VIL
VOH
0.3.
4.0
V
V
RDI, LO:
Input Low Current
Input High Current
IIL
IIH
6
7
8
9
Switch Hook Detect
Threshold
10
Relay driver current sink
capacity
ILOOP
Min
Typ†
Characteristic
23
16
15
25
18.5
16.5
Max
-0.5
+1.2
10
IDO
50
Units
mA
mA
mA
75
mA
* All DC Electrical Characteristics are with VCC at +5.0V +5% and VBAT at -48V, and at 25°C unless otherwise stated.
†
Typical figures are for design aid only and are not guaranteed.
‡
RLOOP includes 300R for telephone set.
1
Operating IBAT is dependent upon the users application.
© Silver Telecom 2004
Test Comments
VRDI = +5V
Ag1110
V2.5 April 2004
Data Sheet
LOW COST PBX SLIC
AC Electrical Characteristics.
Characteristic
Symbol
Min
Typ†
Max
Units
200
300
ms
Test Comments
1
Ring Trip Detect Time, REN=5
2
Ringer Load
3
Input AC Impedance 2-Wire
4
SHK Detect Time
5.0
5
Input Impedance at VIN
100
kohm
6
Output Impedance at VOUT
10
ohm
7
Voltage Gain, Tip/Ring to VOUT
-1.5
-1.0
-0.5
dB
Off-Hook
8
Voltage Gain, VIN to Tip/Ring
-1.5
-1.0
-0.5
dB
Off-Hook
9
Relative Gain, Ref to 1kHz
-0.5
-0.5
dB
300Hz to 3400Hz
10
Total Harmonic Distortion @ 2
Wire and VOUT
THD
1.0
%
@ 0dBm, 1kHz, Off
hook
11
Overload Distortion @ 2 Wire
and VOUT
OD
5.0
%
@ +3dBm, 1kHz, Off
hook
12
Overload level at 2 Wire
13
Common Mode Rejection Ratio
14
Idle Channel Noise
15
Power Supply Rejection Ratio
@ 2 Wire and VOUT
16
Return Loss
17
18
REN
5
600
900
ZIN
CMRR
40
NC
ms
0
dBm
50
dB
0
12
dBrnC
Ag1110
Ag1110-900
No Ringing, No C6
On hook, 1kHz,
AC load = 600R,
RDC Tip-Ring = 20k
300-3400Hz @ 2 Wire
@2 Wire and VOUT
dB
Ripple 0.1V, 1kHz on
VCC and VBAT
38
dB
200-3400Hz
18
21
21
24
dB
200-3400Hz
500-2500Hz
40
46
46
50
dB
dB
300-600Hz
600-3400Hz
PSRR
26
RL
18
Transhybrid Loss
THL
Longitudinal to Metallic Balance
LCL
† Typical figures are at 25°C with nominal 5V supply and are for design aid only.
© Silver Telecom 2004
No false ring trip
ohm
ohm
10
70VRMS Ringing
Ag1110
V2.5 April 2004
Data Sheet
8.0
LOW COST PBX SLIC
Mechanical Specification.
55
Ag1110
13.5
1
5.0
4.0
2.54 ± 0.25
0.6 ± 0.05
Notes:
1. Not to scale.
2. Dimensions in millimeters
3. All figures are typical (unless otherwise stated)
0.6 ± 0.05
Figure 7: Physical Dimensions
© Silver Telecom 2004