SL377 DS2098-2 MV30101 SL376 MV3010-1 MV3010 GL24-1 GL24-2 GL42-1 GL42-2 ITH-15 - Datasheet Archive

 

PURPOSES ONLY AND IS NOT RECOMMENDED FOR NEW DESIGNS SL377 ADVANCE INFORMATION DS2098-2.2 SL377 SUBSCRIBER LINE INTERFACE CIRCUIT

 

THIS DOCUMENT IS FOR MAINTENANCE PURPOSES ONLY AND IS NOT RECOMMENDED FOR NEW DESIGNS SL377 SL377 ADVANCE INFORMATION DS2098-2 DS2098-2.2 SL377 SL377 SUBSCRIBER LINE INTERFACE CIRCUIT The SL377 SL377 is a Subscriber Line Interface Circuit (SLIC) for use at the telephone exchange or PABX end of a telephone line. It provides power feed, transmits and receives voice signals, controls ringing and detects Ground Key or Off-Hook conditions. These functions can be programmed to provide the flexibility required for different telephone networks. The SL377 SL377 is fabricated using bipolar technology. BGND 1 28 LB VREG 2 27 LA VCC 3 26 DB RINGR 4 25 DA TESTR 5 24 RD +CH 6 23 HPB 22 HPA FEATURES s Low Power Line Feed via Regulator s Programmable Constant Current Feed Independent of Battery, to Line s Programmable AC Termination Impedance s Good Longitudinal Balance s Ground Key and Ring Trip Detection s Programmable Off-Hook Detection s Disconnect and Low Power Disable Modes s A-Leg Disconnect, B-Leg Disable Mode s Normal or Reversed Line Polarity Operation s Ring and Test Relay Drivers s Thermal Shut-Down Protection SL 377 VBB 7 SUB 8 21 VTX CHS 9 20 VEE CHCLK 10 19 RSN C4 11 18 AGND E1 12 17 RDC DET 13 16 C1 C2 14 15 C3 DP28 Figure 1: Pin connections - top view VREG BGND 2 1 VBB 7 SUB RSN 9 8 CHS CHCLK 19 10 VTX 21 27 +CH HPB 6 LINE FEED REGULATOR TRANSCEIVER 23 28 24 DC CONTROL AND DETECTORS 22 TESTR DA DB 14 RELAY DRIVERS CONTROL LOGIC 25 26 15 11 12 RING TRIP COMPARATOR 13 20 18 VEE RD RDC 16 4 5 LB 17 HPA RINGR LA C1 C2 C3 C4 E1 DET 3 AGND VCC Figure 2: Functional block diagram 1 SL377 SL377 FUNCTIONAL OVERVIEW The SL377 SL377 Subscriber Line Interface Circuit (SLIC), together with some external components, provides most of the line interface functions for ordinary or PABX line connections in a telephone network. It performs the interface between the two wire line and an ALAP (Analogue Line Audio Processor)/ COMBO, such as the GEC Plessey Semiconductors MV30101 MV30101 SLAC (Subscriber Line Audio Circuit) DSP device. The SLIC circuit contains several functional blocks to achieve the design aims (Fig.2). Firstly, the Transceiver consists of the two wire port, pins LA and LB. These pins are fed from the 4 wire input (RSN) controlling AC conditions, and from the Line Feed Regulator and DC Control blocks, controlling DC conditions. The 2 wire transverse AC signal is fed onto the 4 wire transmit output, VTX. Power dissipation is minimised, under varying line conditions, by the Line Feed Regulator which adjusts the internal high voltage supply to that required for line feed. It consists of a switching regulator which can be synchronised to a 256kHz clock. DC line conditions at the 2 wire interface are determined by the DC Control block. These DC conditions (modes of operation) are set by the Control Logic, which also monitors line status (On/Off-Hook) via the DC Control block detectors (Loop/Ground Key/Ring Trip comparator). The control logic also controls the Ring Relay Driver for Ringing mode of operation and an undedicated Test relay driver. A brief outline of the device functionality is given below, before a more detailed discussion of the SLIC circuitry in the Functional Description section. LINE FEED Line loop (pins LA &LB) feeding is obtained from the battery supply (pin 7) by means of an internal power circuit, which can be set to different modes of operation (refer to table 2). These modes are as follows: Disable Mode Disable mode is the SLlC's low power mode in which the battery feed circuit limits the DC loop current to a level just sufficient to enable the SLIC to detect current above the On/ Off-Hook threshold. Both the Loop and Ground Key detectors work in this mode. Disconnect A and B Leg This mode programs the SLIC such that the A and B leg output amplifiers are turned off, preventing current flow to the line. Disconnect A, Disable B Leg This is the SLIC Standby mode with the A Leg amplifier turned off, so that current can only flow in the B Leg. In this state it is only possible to detect the application of a ground to the B Leg. Actlve Mode This is the normal operating mode with a call in progress. The SLIC is used as a constant current feed device, with the feed current being set by external resistors. Polarity Reversal The polarity of the feeding voltage at the SLIC can be reversed on command, in Active and Disable modes. All Active and Disable conditions apply equally to the respective reverse conditions. In these conditions the polarity of any DC parameter is reversed. 2 Ringing This mode enables the Ring Relay output and selects the Ring Trip comparator. It does not provide DC line feed or AC ringing voltage which must be supplied externally (via the ring relay). Test Mode Testing of the line is not performed by the SLIC. This mode enables external access to the telephone line by directly driving the test relay. SUPERVISION The SLIC provides an Off-Hook (or loop) Detector (OHD), Ring Trip Detector (RTD) and a Ground Key Detector (GKD). These are described below, in addition to the SLIC on-chip thermal protection. Off-Hook Detector The Off-Hook Detector recognises the loop status by means of a threshold circuit. The OHD operates in Disable and Active modes (with or without polarity reversal), and in the presence of longitudinal currents. The detector threshold is nominally the same in Disable and Active modes, the actual level being externally programmable. Ring Trip Detector This detects when a subscriber goes off-hook during the application of a ringing signal (normally 25Hz) within a maximum delay of 150ms (determined by external components - see Applications section). The detector is active when the Ring Relay Driver is activated. Ground Key Detector The GKD circuit detects a current path from the A or B Leg to ground. It can be used in Disable, Active and Disconnect A Disable B modes. Thermal Protection In conditions which cause the chip junction temperature to rise above a critical level (around 150°C), the thermal protection will operate. This switches off the line current and therefore reduces the power dissipation. TRANSMISSION The signal transmission functions include 2 to 4-wire and 4 to 2- wire conversions. The 2-wire termination impedance of the SLIC is programmed by external components. Transmit and Receive Gain are fixed and are nominally both unity (0dB), with the 2wire port terminated in a matched load. All the transmission parameters apply when the SLIC is operating in the presence of longitudinal currents, as specified in the Electrical Characteristics. CONTROL The SLIC is provided with a digital interface for controlling the 2-wire line status and passing line status information to the line card/system hardware. The operating characteristics can be selected by hardware with external components (see Digital Interface). METERING Injection of high amplitude high frequency meter pulses is not supported by the SL377 SL377. If this function is required, then the GPS SL376 SL376 Metering SLIC can be used instead (refer to separate Data Sheet). SL377 SL377 RINGING The application of the ringing voltage to the subscriber line can be via a relay or suitable high voltage crosspoint, external to the SLIC. This component is driven by the on-chip Ring Relay Driver. The relay is connected between RINGR and VBAT. When the SLIC is set to RING mode, the Ring Relay Driver output will be activated to energise the ring relay. The relay should be connected so as to cause the line to be disconnected from the SLIC and connected to a suitable ringing supply (continuous) voltage. Ring cadence can then be obtained by de-energising and re-energising the relay as required. OVERVOLTAGE PROTECTION Overvoltage protection is required to protect the SLIC from such line phenomena as lightning strikes, and induced AC signals from, or direct contact with, power lines. This protection can be realised with components external to the SLIC (refer to SLIC Application Note AN82). INTERFACES The SLIC has three main interfaces to external circuitry. These are the 2-wire, 4-wire and Digital interfaces which are described below. Subscriber Line Interface (2-wire port) Pins LA and LB form the Subscriber Line Interface providing line feed, signalling supervision and voice transmission between the subscriber's apparatus and exchange. It exhibits very good balance about ground to minimise the crosstalk between adjacent pairs in the local cable and noise from longitudinal interference. The termination impedance is set externally by ZTX (see Fig. 3 and Functional Description). The 2-wire port is designed to offer a low impedance to any longitudinal signals that appear on the subscriber line and the resulting signal level at the 4-wire output port is minimised. It is able to handle longitudinal currents on the subscriber line in all modes of operation, except Disconnect mode, Ringing and Disconnect A Disable B when the SLIC 2-wire port is no longer connected to the line. Analog 4-wire interface Two pins of the SLIC (VTX and RSN), together with associated grounds, provide the 4 wire interface to an ALAP or COMBO device. Both the transmit (VTX) and receive (RSN) signals are unbalanced and have fixed gain settings. The VTX pin has a low output impedance, whilst the RSN pin is a low impedance virtual earth input. The input current is normally a combination of the receive voice signal from the ALAP, line feed current programmed by the RDC pin (see Applications section) and termination of the VTX pin. Hybrid Balancing is not provided on the SLIC. This can be done by an ALAP such as the MV3010-1 MV3010-1 SLAC which uses DSP techniques, including an Adaptive Echo Cancellation feature. Digital Interface This is a parallel interface providing control of all the SLIC operating modes and indication of line status information. It consists of the 6 pins as listed in Table 1, the functions of which are described in Table 2. Pin designation Pin description C1 C2 C3 C4 E1 DET Data Input Data Input Data Input Test Select Input Detector Select Input Detector Data Output Table 1: Digital interface pin designation DET output status (Note 2) Mode C4 C3 C2 C1 E1 = 0 E1 = 1 Test relay Disconnect A & B Legs Ringing Active (non-ringing) Disable Disconnect A, disable B Reserved Active, polarity reversed Disable, polarity reversed Line test (note 1) X X X X X X X X 0 1 0 0 0 0 1 1 1 1 X X 0 0 1 1 0 0 1 1 X X 0 1 0 1 0 1 0 1 X X (Invalid) Ring Trip (Note 3) Loop Detect Loop Detect (Invalid) Loop Detect Loop Detect - (Invalid) Ground Key Ground Key Ground Key Ground Key Ground Key - Enabled Disabled NOTES 1. C3, C2, C1 still change SLIC status even though Line outputs will be disconnected from line. 2. DET = 1 for On-Hook (high line impedance), DET = 0 for Off-Hook (low line impedance). 3. DET = 1 for Voltage DA > DB, DET = 0 for Voltage DA < DB. Table 2: Digital interface functional description 3 SL377 SL377 FUNCTIONAL DESCRIPTION TX VOICE TRANSMISSION AND RECEPTION It is conventional to assign the signal directions from the point of view of the served telephone set. The receive direction is towards the served telephone and the transmit direction is from it. The basic voice circuit for the device is shown in Fig.3. The current which flows on the line, into LA and out of LB is 1000 times the current which flows into RSN and through the device to AGND. The AC voice current flowing into RSN is composed of the current from VRX through ZGR, which controls the signal received at the remote telephone and a current from VTX through ZTX which controls the termination impedance. There is also a DC current at RSN which is analysed later in the discussion on DC line feed. The 2-wire termination impedance is ZAB = (ZTX ÷) where a (1000) is the current gain between RSN and IL (see Fig.3). This can be checked by setting VRX to zero. The Receive Gain, for normal voice signals (at VRX). is inversely proportional to ZGR. The actual value, which is negative, can be obtained by setting (VL)ac equal to zero in Fig.3. This gives:AC voltage between LA and LB (VLA-VLB)ac = (VLA-VLB)-(VHPA-VHPB) = (IL)ac x {ZAB||ZL) =Z ZL x ZTX L + ZTX VRX VGR -VRXZLZTX (ZL + ZTX)ZGR In the transmit direction, the voltage at V TX is the superposition of the voltage from the line, with the voltage produced on the line from VRX, i.e:- ZL (IL)ac 27 22 (VL)ac LA VTX L L TX VRX L L TX ZGR This expression simplifies to :[ZGR(VL)ac-ZLVRX]ZTX VTX = (ZL + ZTX)ZGR This equation can be used to determine the transmit gain, from (V L ) ac to V TX , by setting V RX = 0 which gives +ZTX÷(ZL+ZTX). The 4 wire-4 wire gain, VRX to VTX, is also given by this equation when setting (VL)ac = 0, which gives us the alternative result -ZLZTX[(ZL+ZTX)ZGR].If fuse resistors are included in the 2 wire loop, then ZL is modified to become (ZL + 2RFUSE) in the above equations. The transmission circuitry also contains a longitudinal feedback circuit, such that the SLIC appears as typically 25 resistors from LA and LB to a bias voltage (see DC Line feed section). This bias voltage comes from the DC feed circuitry. The feedback circuit attenuates longitudinal signals from the transmit path, and has no effect on transverse signals. DC line feed (loop) current IL = 1/2(|IA-IB|) is provided by the device when it is in non-ringing modes. In RING mode, DC line feed and AC ringing voltage are normally applied through the Ring relay which is controlled by the device. The line feed current is reduced during standby operation. In Active mode, Power feed is controlled by the resistance RDC (= RDC1 + RDC2) between the RDC pin and the RSN pin (Fig.4). Again, the current in the 2 wire loop will be 1000 times the current into RSN. Operation of the DC feed circuitry is described with reference to Fig.4, which shows a conceptual model. For the normal line feed region, a voltage V DC, of magnitude 2.5V is produced at the RDC pin. The sign of VDC determines normal or reverse polarity operation. If negative, normal polarity is established and if positive, reverse polarity will occur (polarity is set by control logic see Table 2). This normal line feed region exists when |VBAT|-|VDCT|VSG(VSG = 15V nominally, VDCT = |VLA - VLB|), else the Saturation Guard circuit is active (described later). (VIRTUAL EARTH) RSN 19 IRSN I=IRSN; ZGR VRX HPA (VLA-VLB)ac VOICE I/P 1000 VTX=(VLA - VLB) - (VHPA - VHPB) 23 28 HPB LB ZTX VTX (IL)ac Figure 3: Voice circuit 4 TX Z x Z V Z +Z DC LINE FEED (ACTIVE MODE) i.e. minus the ratio of the line and terminating impedances (ZL and ZTX÷ a) in parallel, to the receive impedance divided by the current gain (ZGR ÷ a). This expression simplifies to := Z = Z ÷ Z 21 VTX SL377 SL377 The remaining circuitry models the action of the saturation guard circuit. This operates to reduce the voltage at the RDC pin when:- |VBAT|-|VDCT|ILLT - ILL COMPARATOR DA VSG with IL = IFEED = (2500 ÷ RDC) 4. Saturation Guard Threshold when |VBAT|-|VDCT| = VSG = 15.0V such that :VL = VLSG = |VBAT|-VSG{2RFUSE x (2500 ÷ RDC)] RLSG = [(|VBAT|-VSG) x (RDC ÷ 2500)]-[2RFUSE] which will equal |VBAT|-VSG with 2RFUSE = 0 and 5. Saturation Guard feed Region when |VBAT|-VDCT| < VSG with IL = [|VBAT|-VSG] ÷ [RL ÷ 2RFUSE] 6. Note that VLSG is referred to as the value of the line voltage, VL, at the point where Saturation Guard becomes active. This will differ from the value of |VLA-VLB| (i.e. VDCT) if 2RFUSE 0. VSG is used as a notional threshold voltage which is the internal headroom between the |VLA-VLB| voltage and the battery supply, at this same point. 7. Open Circuit Line Voltage VLOC at RL= such that :- VL=VLOC [|VBAT|-VSG] VLOC will be VLSG even with 2RFUSE=0. The voltage drop from VLOC to the defined VLSG point will be greater at lower values of VBAT 8. 2 Wire Termination Impedance ZAB = (ZTX ÷ ) = (ZTX ÷ 1000) Note that ZTX is normally set to [(ZL ÷ 2RFUSE)] where ZL is the desired termination impedance. 9. Receive Gain from VRX to (VLA-VLB)ac or (VLINE)ac is set by ZGR after setting ZTX . Thus, with (VL)ac = 0 :(VLA - VLB)ac = VRX -ZLZTX [(ZL) + ZTX]ZGR (VLINE)ac = with 2RFUSE = 0; 10. Resultant Transmit Gain is then :- VRX (VL)ac 11. Resultant 4 Wire-4 Wire Gain is then :- VRX [(ZL + 2RFUSE) + ZTX]ZGR with 2RFUSE 0 ZTX = VTX VRX -ZLZTX [(ZL + 2RFUSE) + ZTX with VRX = 0 -(ZL + 2RFUSE) + ZTX = [(ZL + 2RFUSE) + ZTX]ZGR with (VL)ac = 0 11 SL377 SL377 12. Off-Hook Threshold is set by RTH at :- IL = IDET = 350 ÷ RTH. 13. Ring Trip Threshold is set by the bridge associated with pins 25 . 28 and the 2 Wire Line, thus :RL = RLTH = RB4(2RF) ÷ (RB4-RB1) assuming RB1 = RB2, RB3 = RB4 and RFEED1 = RFEED2 for the bridge components (balanced ringing). RB1.RB4 a few 100K and RFEED1 a few 100 . 14. AC ringing voltage at DA (DB by the same amount) is reduced by a factor of :- [1 + (2frtr)2]1/2 fr is the ringing frequency and tr is determined by the bridge components including CB, thus :for balanced ringing. tr = 2RB1RB4CB (RB1 + RB4) APPLICATIONS The requirements for the subscriber line interface vary considerably from one telephone administration to another The SL377 SL377 is designed to have the flexibility to meet these varying requirements. For simplicity, only a single example is given to illustrate how the device is connected. Fig. 11 shows the circuit which can be used to evaluate the device. Further Applications information is given in SLIC Applications Note AN82. TEST ACCESS TEST RELAY RING RELAY RFUSE =20 RFEED2 =400 COMPOSITE SIGNAL (2-WIRE) LINE AND PROTECTION CIRCUITRY RSRINGING SOURCE RFEED1 =400 RFUSE =20 RS+ VBAT VBAT 1k 1k 10n RB3 RB4 10n +5V BGND VREG 560p 8.2n 1mH 470n 100V 100mA 2.4k 100n AGND VBB DB RINGR DA TESTR BGND RD +CH VBB 100 HPB SL HPA 377 SUB CHS AGND 100V 100mA REGULATOR CLOCK CHP RTH=32k 4-WIRE TRANSMIT 330n CHCLK ZTX=600k 4-WIRE RECEIVE ZGR=300k 100n RSN AGND E1 RDC DET C1 C2 82n -5V RDC1 = RDC2 = 31.25k C3 AGND DIGITAL INTERFACE Figure 11: Application circuit 12 RB3 = RB4 = 100k RB2 VEE C4 BATTERY SUPPLY VBAT RB1 = RB2 = 120k RB1 CB=100n VTX 330n 100V 100mA RING TRIP AT RL = 4k LA VCC 470n RESISTANCE BRIDGE NETWORK LB AGND SL377 SL377 The DA and DB pins are connected to a resistance bridge network (RB1 to RB4). This allows the change in line resistance to be sensed when the remote telephone goes off-hook during ringing (ring trip). The details of this network (and CB) are given later (see Ring Trip section). The resistors RFEED1 and RFEED2 provide feeding of the ringing source onto the line during ringing mode. The Ring Relay coil is connected through current limiting resistors. Connections to the LA and LB pins are shown, and include the resistors RFUSE in addition to the ring relay. These resistors have a value around 20 to 30 ohms, depending on the application, and provide current line protection. Overvoltage and protection circuitry may consist of slewlimiting inductors between the pins and the line itself and a thyristor or Zener protection network at the line. In many applications, especially in PBXs, the amount of protection circuitry can be reduced. The capacitors between LA, LB and ground, allow noise from the regulator to be decoupled. The capacitor CHP between HPA and HPB is used to filter out the AC component of the signal on the line. The voltage difference between the two pins should be effectively DC. The SLIC Application Note AN82 contains a further discussion on this component. The resistor, RTH. between RD (pin 24) and VEE (pin 20) programs the threshold current for the loop detector. A capacitor in parallel can be added to reduce the effect of the AC component of the line current, but this can cause instability on standby operation with highly inductive lines if it is too large. The value of RTH sets the current IDET according to the relationship:IDET = 350 ÷ RTH The CHS pin (pin 9) is connected to BGND through a capacitor and to VREG by a capacitor and resistor in series. This stabilises the regulator control loop (pins 2, 6 and 7). It is recommended that the substrate (SUB) pin is decoupled to AGND. However, BGND may be used if this is sufficiently quiet, otherwise some degradation in noise performance may be experienced. DC current flows between RDC (pin 17) and RSN (pin 19). This is used to set the line feed current. Any minor AC fluctuations are reduced by dividing the resistance equally such that RDC1 = RDC2 = 1/2RDC and connecting a capacitor from the junction of RDC1 and RDC2 to AGND. The network (ZTX) between VTX and RSN controls the AC terminating impedance. This can also be a complex impedance. The value of ZTX can be calculated from the relationship :ZTX = (Required ZT) x (Receive current gain) Connections for both Ring and Test relays are also shown in Fig 11. Note that the 1k resistors provide current limit through the relay coils when the driver outputs are on. Control and status pins are compatible. They are designed to give a simple interface to digital circuits and are directly compatible with the MV3010 MV3010 SLAC. RING TRIP Ring Trip detection operates by comparing the voltages on DA and DB and providing the output on DET when this function is enabled using the status input pins of the Digital Interface. A resistance bridge (RB1 to RB4) must be connected to the line and to the ringing voltage sources to cause the differential voltage between DA and DB to change sign when the line resistance falls below the level associated with Ring Trip. Note that it is simplified by use of RB1 = RB2 and RB3 = RB4 (see discussion in AN82). Ringing voltage is normally applied to the line through the Ring Relay which is activated by RINGR. The ringing voltage sources, including line feed, are connected to the line via ringing feed resistors, RFEED1 and RFEED. The resistance bridge operates by allowing the DC voltage dropped across the ringing feed resistors (RF) in the OffHook condition to reverse the polarity of the voltage on DA and DB (DA< DB). Since the AC ringing voltage is greater than the DC feed, the capacitor CB (Fig. 12) will filter this out at the comparator inputs. The connection shown is suitable for balanced ringing only. For unbalanced ringing, separate capacitors from DA (CBI) and DB (CBZ) to ground will be required to achieve the same result. Fig. 12 shows how the resistance bridge is connected when used with balanced ringing. The circuit can operate correctly provided there is a DC feed in addition to the AC ringing voltage. If RLTH is the line resistance correspondlng to the Ring Trip threshold (DA =DB), this can be determined from the values of RF (RFEED1 = RFEED2 = RF), RB1 and RB4 (RB1 = RB2, RB3 = RB4 as:RLTH = RB4(2 RF ) (RB1-RB4) RINGING SOURCE { RB1 and RB4 should be a few hundred k. + RFEED1 A-LEG LINE RB1 RB4 DA The amplitude of the AC ringing voltage at DA (DB is by the same amount) is reduced by a factor of [1 + (2frtr)2]-1/2 where fr is the ringing AC frequency and tr is set by:- CB RLINE RB3 DB B-LEG RFEED2 RB2 RFEED1 = RFEED2 = RF tr = 2RB1RB4CB (RB1 + RB4) for balanced ringing. For fr 20Hz, tr should be 50ms. For unbalanced ringing CB will become CB1CB2 ÷ (CB1 + CB2) in the above equation. More detail on Balanced and Unbalanced Ringing is given in AN82 Figure 12: Ring trip circuit (balanced ringing) 13 SL377 SL377 PIN DESCRIPTIONS Symbol Pin no Pin name and description BGND 1 Battery Ground (Power Input). 0 Volts. VREG 2 Regulated Voltage (Negative Power Input). The voltage at this pin is compared to that required for line feed, and the result is used to control the voltage regulator. VCC 3 Positive Supply (Power Input). + 5 Volts. RINGR Ring Relay Driver Output, Transistor Emitter. This output is designed to drive a relay, when used together with the VBAT supply. TESTR 5 Test Relay Driver Output (Pull-up Output) This output is designed to drive a relay, when used together with the VBAT supply. +CH 6 Switching Regulator (Chopper) Output (Negative Power Output). Chopper switch transistor collector. An internal regulator controls the mark/space ratio of the switching waveform to maintain VREG (pin 2) at the required voltage. VBB 7 Battery Voltage (Negative Power Input). This is the -50 Volt battery supply pin which connects to the VBAT supply via an external diode. It is connected to the chopper switch emitter. SUB 8 Substrate (Decoupling Node). An external decoupling capacitor (0.33µF) should be connected between this pin and AGND. CHS 9 Line Feed Regulator (Chopper) Stabilising Network. This is the input to the voltage comparator which is used to control the switching regulator. CHCLK 10 Line Feed Regulator (Chopper) Clock (Digital Input). This is the positive edge triggered, 256kHz clock input for the voltage regulator, which will free run in the absence of an input signal. C4 11 Control Input (Digital Input). Enables the Test relay driver output pin. E1 12 Control Input (Digital Input). Selects the line status detector (Loop or Ground Key). DET 13 Detector Data output (Digital Output). This pin outputs the status of the detector which has been selected by D0 - D3. C2 C3 C1 14 15 16 Control Input (Digital Input). Control Input (Digital Input). Control Input (Digital Input). RDC 17 DC Reference Voltage (Voltage Output). A reference voltage of ± 2.5Volts ( ± depending on line polarity), is output at this pin, excepting Saturation Guard operation. AGND 18 Analog Ground (Analog Reference Node). This is the ground reference pin for the analog signals. It also provides a ground reference for the Digital Interface. Signal reference and decoupling connections should be separately run to this pin. RSN 19 Receive Summing Node (Current Input). The current which is input on this pin is used to control the transverse current at LA and LB. 14 These inputs determine the SLIC operating mode, and control the ring relay, selection of ringing and non-ringing Modes, line polarity, line status and line detector. SL377 SL377 VEE 20 Negative Supply (Power Input). - 5 Volts. VTX 21 Transmit Voltage (Voltage Output). The voltage output at this pin is equal to the difference between the voltage (VLA-VLB) and the differential DC voltage (VHPA-VHPB), multiplied by the 2 to 4-wire voltage gain. HPA HPB 22 23 High Pass A, High Pass B - AC/DC separation (Voltage Inputs). These inputs sense the DC feed voltages on the LA and LB pins respectively . Under normal operation they are connected to LA and LB respectively by internal resistors and should be connected as shown in Fig. 11. RD 24 Loop Detection Control (Current Output / Voltage Input). This pin outputs a current which equals the transverse loop current through LA and LB divided by 280. Off-Hook is indicated via the DET pin when the voltage at this pin is (VEE + 1.25) Volts. DA DB 25 26 Ring Trip Detector A, Ring Trip Detector B (Voltage Inputs). These are the A and B inputs to the internal ring trip comparator. The output of the comparator controls the ring trip output on DET. LA LB 27 28 A Line Transceiver, B Line Transceiver (Current Outputs / Voltage Inputs). These two pins form the 2-wire port connecting to the subscriber loop. ELECTRICAL CHARACTERISTICS Operating Range VCC = +5.0V ± 5%, VEE = -5.0V ± 5%, VBAT = -40.5V to -64.0V (typical -48V), VBGND = -0.1V to +0.1V, VIH = 2.0V, VIL = 0.7V, ZL = . Voltages are measured with respect to analog ground (VAGND). Temperature Tamb = 0°C to +70°C. Test Levels 1. Tested over full operating range. 2. Tested at 25°C but guaranteed over the full operating range. 3. Not tested, but guaranteed by characterisation. Supply Characteristics Characteristic Symbol Min. Value Typ. Max. Units Conditions Test level Positive supply (VCC) current, disconnect mode ICC1 4 mA Positive supply (VCC) current, disable mode ICC2 10 mA On / Off-Hook, lL = 0 2 Positive supply (VCC) current. active mode ICC3 10 mA On / Off-Hook, IL = 0 2 Negative supply (VEE) current, disconnect mode IEE1 2 mA Negative supply (VEE) current disable mode IEE2 4 mA On / Off-Hook, lL = 0 2 Negative supply (VEE) current active mode IEE3 4 mA On / Off-Hook, lL = 0 2 Battery supply (VBB) current disconnect mode IBB1 1.5 mA Battery supply (VBB) current disable mode IBB2 5 mA On-Hook, lL = 0 Battery supply (VBB) current active mode IBB3 6 mA On-Hook, lL = 0 2 2 2 2 2 15 SL377 SL377 Supply Characteristics (continued) Characteristlc Symbol Positive supply (VCC) rejection ratio, supply to 2-wire transverse Min. PSRT Value Typ. Max. 17 Units dB dB Conditions Test level See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 See note 2; 50mV on supply, 3003400Hz, ZL = 600 2 PSRL Positive supply (VCC) rejection ratio, supply to 2-wire longitudinal 17 Negative supply (VEE) rejection ratio, supply to 2-wire transverse NSRT 17 Negative supply (VEE) rejection ratio, supply to 2-wire longitudinal NSRL Battery supply (VBB) rejection ratio, supply to 2-wire transverse BSRT Battery supply (VBB) rejection ratio, supply to 2-wire longitudinal BSRL Power dissipation, active state PWA 1.00 W ZL = 600 2 Power dissipation, active state standby state, on hook PWD1 0.35 W IL = 0 2 dB 17 dB 27 dB 27 dB ANALOG CHARACTERISTICS Characteristic Symbol Min. VOAB 2-wire port, longitudinal impedance ZLL Longitudinal current limit, active state ILLA 17.5 Longitudinal current limit, disable state ILLS 3.6 Longitudinal current limit, active state, B leg ILLB 63 Conditions Test level Max. Units + 3.1 V See Fig 13, note 4: VR = (pk) 1000Hz, EL = 0V, 3 35 - 3.1 2-wire port, low freq overload level 16 Value Typ. /wire See Fig 14: f 2.35) 2 CHCLK input frequency FCLK 256 kHz 2 CHCLK min. pulse width TCLK 500 ns 3 20 2 SL377 SL377 Recommended Operating Range Characteristic Symbol Min. Value Typ. Max. Units Positive supply voltage VCC +4.75 5.0 +5.25 V Negative supply voltage VEE - 4.75 - 5.0 - 5.25 V Battery supply voltage VBAT - 40.5 -48 - 64 V Battery ground voltage VBGND -0.1 +0.1 V Ambient temperature TAMB 0 +70 °C R1 IL VA R3 IR LA VR RSN SL377 SL377 EL Conditions LB R2 VT VTX VB GT = 20 log (VT ÷ VA-B) dB; VR = 0V GRI = 20 log (IL ÷ IR) dB; EL = 0V GR = 20 log (VA-B ÷ VR) dB; EL = 0V R1 = 600 R2 = 600k R3 = 300k Figure 13: Test configuration (Note the SL377 SL377 block = Fig 24) Z1 IL VA C R3 IR LA VR RSN SL377 SL377 VA-B R2 Z2 ELL LB VB +2dBu VT VTX (L-T) = 20 log (ELL ÷ VA-B) dB; VR = 0V (L - 4) = 20 log (ELL ÷ VT) dB; VR = 0V ZLL = ZL ÷ 2 x [(ELL ÷ VA) -1] 1÷wC < ZL Z1 = Z2 = 1/2ZL Z1 ÷ Z2 = 1 ± 0.0001 R2 = 600k R3 = 300k < Figure 14: Test configuration (Note the SL377 SL377 block = Fig 24) Z1 ILL1 C R3 IR LA VR RSN SL377 SL377 R2 Z2 ELL LB ILL2 Z1 = Z2 = 1/2ZL Z1 ÷ Z2 = 1 ± 0.0001 R3 = 300k VT VTX ER < 1÷wC < ZL R2 = 600k Figure 15: Test configuration (Note the SL377 SL377 block = Fig 24) 21 SL377 SL377 R1 IL R3 IR LA VR RSN SL377 SL377 VA - B LB VT VTX R3 = 600k GR = 20 log (VA-B ÷ VR)dB R1 = 600 Figure 16: Test configuration (Note the SL377 SL377 block = Fig 24) Z1 R3 LA C EL VR RSN SL377 SL377 R2 Z2 LB VLL +2.6dBu EL should not be referenced to ground Z1 = Z2 = 1/2ZL Z1 ÷ Z2 = 1 ± 0.0001 VT VTX (T-L) = 20 log (EL ÷ VLL)dB; VR = 0V R2 = 600k R3 = 300k 1÷wC < < ZL Figure 17: Test configuration (Note the SL377 SL377 block = Fig 24) Z1 R3 VA LA C VR RSN SL377 SL377 R2 Z2 VLL LB VT VTX ER VB +2.6dBu Z1 = Z2 = 1/2ZL Z1 ÷ Z2 = 1 ± 0.0001 R3 = 300k (4-L) = 20 log (ER ÷ VLL) dB; VR = 0V R2 = 600k 1÷wC < ZL < Figure 18: Test configuration (Note the SL377 SL377 block = Fig 24) 22 SL377 SL377 -40 B -50 C -60 A dBu -70 D -80 -90 1k 2k 5k 10k 20k 50k 100k 200k 500k 1M FREQUENCY (Hz) A = 4kHz B = 7kHz Bandwidth = 3kHz VA-B < -73dBu FREQUENCY AT CENTRE OF BAND C = 15kHz -50dBu D = 100kHz -73dBu Minimum Centre Frequency = 1.6kHz f > 1MHz Figure 19: 2-Wire differential noise 23 SL377 SL377 -40 -50 -60 A dBu -70 -80 B -90 1k 2k 5k 10k 20k 50k 100k FREQUENCY (Hz) FREQUENCY AT CENTRE OF BAND A = 15kHz -61dBu B = 200kHz -80dBu Bandwidth = 3kHz f > 1MHz VLL < -73dBu Figure 21: 2-Wire longitudinal noise 24 200k 500k 1M SL377 SL377 VA C1 LA RSN Z1 L1 VLL SL377 SL377 VA-B Z3 Z2 Rdc VB C2 LB Rdc = 600 or 1600 C1 = C2 = 100µF AGND R2 VTX L1 = 18H Z1 = Z2 = 68 C2 ÷ C1 = 1 ± 0.01 Z3 = 56 R2 = 300k Figure 21: Test configuration (Note the SL377 SL377 block = Fig 24) RA IRTDA LA VCMM RA = RB = R SL377 SL377 VRTO RB IRTDB LB GND RA = RB = R Figure 22: Test configuration (Note the SL377 SL377 block = Fig 24) LA RW SW1 RG SL377 SL377 RW GND LB GND OFF-HOOK: Midpoint of LA and LB connected to ground via RG ON-HOOK: LB connected to ground via RG Figure 23: Test configuration (Note the SL377 SL377 block = Fig 24) 25 SL377 SL377 +5V BGND AGND R4 VBB D4 C3 +CH HPB CHCLK CHP AGND E1 DET R2 RDC1 RDC2 C3 L1 = 1mH RSUB = 100 RTH =32k RDC1 = RDC2 = 31.25k (See Elec. Char.) ZL= See Electrical Characteristics For all tests assume AGND = BGND Figure 24: Test circuit for Figures 13 - 18 and 21 - 23 26 -5V CDC AGND CDC = 82n D1 = 100V, 100mA D2 = 100V, 100mA D3 = 100V, 100mA D4 = 100V, 100mA R3 C9 C1 C2 C6 = 100n C7 = 10n C8 = 10n C9 = 100n CHP = 330n 4-WIRE CONNECTIONS RDC DIGITAL INTERFACE C1 = 470n C2 = 470n C3 = 560p C4 = 8.2n C5 = 330n RTH RSN C4 REGULATOR CLOCK AGND VEE AGND BATTERY SUPPLY VBAT R1/ZL C8 AGND VTX CHS AGND 2-WIRE CONNECTIONS C7 SL 377 HPA SUB C5 D3 RD VBB RSUB D2 DA TESTR C6 L1 C2 DB RINGR D1 C4 LA VCC BGND LB VREG 470n AGND R1 sa Test Configuration R2 as Test Configuration R3 as Test Configuration R4 = 2.4k AGND SL377 SL377 ABSOLUTE MAXIMUM RATINGS* - Voltages are with respect to analog ground (VAGND). Value Parameter Symbol Min. Max. Battery supply voltage VBB - 70 + 1.0 V Continuous battery ground voltage VBGNDC - 0.3 + 0.3 V Intermittent (10µs) battery ground voltage VBGNDI -4.0 +4.0 V Positive supply voltage VCC - 0.4 + 7.0 V Negative supply voltage VEE - 7.0 + 0.4 V Subscriber line voltage on LA, LB or both, continuous VLC - 70.0 + 0.4 V Differential DC line current ILDC 150 mA Switched regulator voltage (off) VCH + 1.0 V Switched regulator current (on) ICH 150 mA Relay drivers output voltage VRLY Relay Drivers output source current IRLY Ring-Trip input voltage (DA or DB) VRT Ring-Trip input current (non-repetitive 10ms pulse) VBB Units VBAT V 30 mA VBB 0 V IRT -10.0 + 10.0 mA Digital input voltage VID - 0.4 VCC V Digital input current (sink) IID 5.0 mA Digital output voltage VOD VCC V Digital output current (source) IOD 3 mA Storage temperature TST + 125 °C Operating junction temperature TJOP + 150 °C Package power dissipation (DG28) PPDG28 PPDG28 1.5 W -0.3 - 55 * Exceeding these ratings may cause permanent damage. Functional operation under these conditions is not implied. Circuit includes thermal protection such that TPROT (Min) = 150°C. 27 SL377 SL377 HEADQUARTERS OPERATIONS GEC PLESSEY SEMICONDUCTORS Cheney Manor, Swindon, Wiltshire SN2 2QW, United Kingdom. Tel: (0793) 518000 Fax: (0793) 518411 GEC PLESSEY SEMICONDUCTORS P.O.Box 660017, 1500 Green Hills Road, Scotts Valley, California 95067-0017, United States of America. Tel (408) 438 2900 Fax: (408) 438 5576 CUSTOMER SERVICE CENTRES · FRANCE & BENELUX Les Ulis Cedex Tel: (1) 64 46 23 45 Fax: (1) 64 46 06 07 · GERMANY Munich Tel: (089) 3609 06-0 Fax : (089) 3609 06-55 · ITALY Milan Tel: (02) 66040867 Fax: (02) 66040993 · JAPAN Tokyo Tel: (3) 5276-5501 Fax: (3) 5276-5510 · NORTH AMERICA Integrated Circuits and Microwave Products, Scotts Valley, USA Tel (408) 438 2900 Fax: (408) 438 7023. Hybrid Products, Farmingdale, USA Tel (516) 293 8686 Fax: (516) 293 0061. · SOUTH EAST ASIA Singapore Tel: 2919291 Fax: 2916455 · SWEDEN Johanneshov Tel: 46 8 702 97 70 Fax: 46 8 640 47 36 · UK, EIRE, DENMARK, FINLAND & NORWAY Swindon Tel: (0793) 518510 Fax : (0793) 518582 These are supported by Agents and Distributors in major countries world-wide. © GEC Plessey Semiconductors 1994 Publication No. DS2098 DS2098 Issue No. 2.2 January 1994 This publication is issued to provide information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. The Company reserves the right to alter without prior knowledge the specification, design or price of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to the Company's conditions of sale, which are available on request. 28 http://www.zarlink.com World Headquarters - Canada Tel: +1 (613) 592 0200 Fax: +1 (613) 592 1010 North America - West Coast Tel: (858) 675-3400 Fax: (858) 675-3450 Asia/Pacific Tel: +65 333 6193 Fax: +65 333 6192 North America - East Coast Tel: (978) 322-4800 Fax: (978) 322-4888 Europe, Middle East, and Africa (EMEA) Tel: +44 (0) 1793 518528 Fax: +44 (0) 1793 518581 Information relating to products and services furnished herein by Zarlink Semiconductor Inc. trading as Zarlink Semiconductor or its subsidiaries (collectively "Zarlink") is believed to be reliable. However, Zarlink assumes no liability for errors that may appear in this publication, or for liability otherwise arising from the application or use of any such information, product or service or for any infringement of patents or other intellectual property rights owned by third parties which may result from such application or use. Neither the supply of such information or purchase of product or service conveys any license, either express or implied, under patents or other intellectual property rights owned by Zarlink or licensed from third parties by Zarlink, whatsoever. Purchasers of products are also hereby notified that the use of product in certain ways or in combination with Zarlink, or non-Zarlink furnished goods or services may infringe patents or other intellectual property rights owned by Zarlink. This publication is issued to provide information only and (unless agreed by Zarlink in writing) may not be used, applied or reproduced for any purpose nor form part of any order or contract nor to be regarded as a representation relating to the products or services concerned. The products, their specifications, services and other information appearing in this publication are subject to change by Zarlink without notice. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. Manufacturing does not necessarily include testing of all functions or parameters. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to Zarlink Semiconductor's conditions of sale which are available on request. Purchase of Zarlink's I2C components conveys a licence under the Philips I2C Patent rights to use these components in an I2C System, provided that the system conforms to the I2C Standard Specification as defined by Philips Zarlink and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc. Copyright 2001, Zarlink Semiconductor Inc. All rights reserved. TECHNICAL DOCUMENTATION - NOT FOR RESALE