AG1110 ETC1
Document overview
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Technical content
V2.5 April 2004 Data Sheet Ag1110 LOW COST SLIC Silver T E L E C O M
FEATURES
- Single-in-line (SIL) PBX SLIC with integral lead frame.
- Highly integrated, requiring a minimum o f external components.
- Constant current f eed to the line, with constant voltage fold over.
- Single +5V system side power supply.
- 16mA minimum loop current into 2000R loop (including telephone set).
- 600R and 900R impedance options.
- Works with a battery of up to –72V.
- Low idle power operation (20mW).
- Short circuit protection.
- Loop open function - loop off under logic control.
- On hook transmission. Control and Supervision PBX SLIC TIP VIN VOUT RIN Figure 1: Single Channel SLIC
DESCRIPTION
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 Silver Telecom Ag1110 comprises a single Subscriber Line Interface Circuit (SLIC) in a single-in-line (S IL) 13 pin format. The combination of features and packaging offers extremely efficient us e of board area, saving significant system size and cost. The system interface has been designed for direct connection to popular codecs for both audio and signalling. The SLIC is highly featured requiring a minimum of external components. Functions such as a relay driv er, are provided on board along with precision loop feed resistors. The Ag1110 is ideal for any application where high-density line interfaci ng 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 Pin Description Pin # Name Description 1 RING Ring. Connects to the subscriber line Ring through the n/c pole of the ringing relay. 2 TIP Tip. Connects to the subscriber Tip. 3 TC Tip Clamp. A diode must be connected externally between TC and Tip to conduct ringing current. 4 RT 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. 5 GND Analog Ground. Normally connected to system ground. 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 TIP TC RT GND VIN VCC VOUT VBAT SHK LO RDI RDO 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 (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.
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 t he 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 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 c ontacting either Silver Telecom or your local representative, to allow the Codec programming coefficients to be generated. The power dissipated in the Ag1110 SLIC is internally limited to a safe value.
1.3 Ringing If a simple Codec is being used, the Ag1110 can only
accommodate countries where the line impedance is 600R (Ag1110), or 900R (Ag1110-900). 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. 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. 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. If a simple Codec is being used the Ag1110 can only accommodate countries where the line impedance is 600R or 900R. . 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. 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 Identificat ion (CLI) information or for other “no ring” calls. With the tip-ring resistor fitted, idle current increases by 2.2mA. VOUT and V IN are normally connected to a Codec for conversion to and from a digital Pulse Code Modulated (PCM) stream. © Silver Telecom 2004
V2.5 April 2004 Data Sheet Ag1110 LOW COST PBX SLIC TC D6TC D6 To MCU TEXAS TCM38C17 C3 0GSX 0ANLGIN- 0PWRO+ 1GSX 1ANLGIN -1PWRO+ 2GSX 2ANLGIN -2PWRO+ 3GSX 3ANLGIN -3PWRO+ +5V -48V0V VIN VOUT VCC TIP RING RING TIP -VBAT SHK LO 90Vrms RDI Ag1110 Silver T E L E C O M D1 K1 RDO VBAT -48V GND RT +0V To MCU TEXAS TCM38C17 C3 0GSX 0ANLGIN- 0PWRO+ 1GSX 1ANLGIN -1PWRO+ 2GSX 2ANLGIN -2PWRO+ 3GSX 3ANLGIN -3PWRO+ +5V -48V0V VIN VOUT VCC TIP RING RING TIP -VBAT SHK LO 90Vrms RDI Ag1110 Silver T E L E C O M D1 K1 RDO VBAT -48V GND RT +0V 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) Figure 5: Ringing Application Diagram with Codec 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. 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
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. 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 cr oss protection components, and a typical circuit is shown in Figure 5. This circuit will meet UL1459 and 1950 requirements. 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. 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).
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 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 © Silver Telecom 2004
V2.5 April 2004 Data Sheet Ag1110 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. 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. 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 switch hook detection output (SHK) from the SLICs are passed to the microprocessor interface so that they can then be proce ssed as necessary by the system software. Similarly the Ringing Relay Control (RDI), and loop off (LO) controls are provided by the controlling processor. The TI device has no facilities for impedance matching and is designed for low cost applications. The 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. 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. 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. 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. Figure 6: LD Dialling Application GND RT RDI GND RT RDI R6 = 470k C6 = 1uF electrolytic R7, R8 = 10k C5 = 10nF ceramic Q1 = general purpose transistor (eg. BC846) 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”. © Silver Telecom 2004
V2.5 April 2004 Data Sheet Ag1110 LOW COST PBX SLIC 7.0 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 TS -20 +85 °C
- Exceeding the above ratings may cause permanent damage to the product. Functional operation under these conditions is not i mplied. 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
V2.5 April 2004 Data Sheet Ag1110 LOW COST PBX SLIC Characteristic Symbol Min Typ† Max Units Test Comments
1 Supply Currents, On-hook
1.75 0.25 2.50 mA Idle Idle 20k Tip-Ring
2 Power Consumption, On-
3 Constant current feed to
18.5 16.5 27 mA RLOOP ‡= 1100R RLOOP ‡=2000R RLOOP ‡=2300R Tip/Gnd or Ring/Gnd or Tip&Ring/Gnd over- current 30 mA VBAT= -48V SHK: Output Low Voltage Output High Voltage VOL VOH 3.15 0.9 V V @0.4mA @-0.4mA SHK: Output Low Voltage Output High Voltage VOL VOH 3.5 0.4 V V @50uA @-50uA RDI, LO: Input Low Voltage Input High Voltage VIL VOH 4.0 0.3. V V RDI, LO: Input Low Current Input High Current IIL IIH -0.5 +1.2 mA mA
9 Switch Hook Detect
10 Relay driver current sink
capacity IDO 50 75 mA VRDI = +5V * 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. 1Operating IBAT is dependent upon the users application. © Silver Telecom 2004
V2.5 April 2004 Data Sheet Ag1110 LOW COST PBX SLIC Characteristic Symbol Min Typ† Max Units Test Comments
1 Ring Trip Detect Time, REN=5 200 300 ms 70VRMS Ringing
2 Ringer Load REN 5 No false ring trip
3 Input AC Impedance 2-Wire ZIN 600
4 SHK Detect Time 5.0 10 ms No Ringing, No C6
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 0 dBm
On hook, 1kHz, AC load = 600R, RDC Tip-Ring = 20k
13 Common Mode Rejection Ratio CMRR 40 50 dB 300-3400Hz @ 2 Wire
14 Idle Channel Noise NC 0 12 dBrnC @2 Wire and VOUT
15 Power Supply Rejection Ratio
@ 2 Wire and VOUT PSRR 26 dB Ripple 0.1V, 1kHz on VCC and VBAT
16 Return Loss RL 18 38 dB 200-3400Hz
18 Longitudinal to Metallic Balance LCL 40
† Typical figures are at 25°C with nominal 5V supply and are for design aid only. © Silver Telecom 2004
V2.5 April 2004 Data Sheet © Silver Telecom 2004 Ag1110 LOW COST PBX SLIC 8.0 Mechanical Specification. 13.5Ag1110Ag1110 4.0 Notes: 1. Not to scale. 2. Dimensions in millimeters 3. All figures are typical (unless otherwise stated) 0.6 ± 0.05 5.0 13.5Ag1110Ag1110Ag1110Ag1110 4.0 0.6 ± 0.05 5.0 Figure 7: Physical Dimensions