MH88600 Global SLIC Preliminary Information Features ISSUE 7 April 1995 Ordering Information • Programmable line impedance matching • Internal complex impedance networks • Transformerless 2-4 wire conversion • Programmable transmit/receive gain • Accommodates worldwide transmission standards • Operates with a wide range of battery voltages • Adjustable constant current battery feed • Overvoltage and short circuit protection • Switch hook and ground button detection • Ring trip filter and relay driver • Low power consumption • High power dissipation capability during fault conditions MH88600 40 Pin DIL Hybrid 0°C to 70°C Description The MH88600 is a SLIC (Subscriber Line Interface Circuit) which provides all of the BORSCH functions of Battery Feed, Overvoltage Protection, Ringing Feed, Line Supervision and 2-4 Wire Hybrid conversion. In addition, the device matches the many different line impedances specified by regulatory authorities of around the world. Applications Line interface for: • PABXs • Control Systems • Key Telephone Systems • Central Office Equipment VREF LCA ZN14 ZN13.................ZN8 ZN7.....................ZN1 ZN0 TF1 Gain Adjust TX PG3 PG1 Ring Trip Filter Ring Drive Vbat SHK GNDBat EGB Relay Driver VEE Line Supervision VDD RF2 PG4 2-4 Wire Hybrid Circuit Over Voltage & Short Circuit Protection GNDA RF1 PG2 VRR RING Impedance Matching Network Constant Current Battery Feed RD TIP Tip Drive RC TF2 Figure 1 - Functional Block Diagram 2-83 MH88600 Preliminary Information VBat RF1 RF2 RING TIP IC GNDBat TF2 TF1 GNDA VEE VDD VRR RC RD LCA SHK EGB VRef 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 ZN14 ZN13 ZN12 ZN11 ZN10 ZN9 ZN8 ZN7 ZN6 ZN5 ZN4 ZN3 ZN2 ZN1 TX PG3 PG1 PG2 PG4 ZN0 Figure 2 - Pin Connections Pin Description Pin # Name 1 2-84 Description No pin at this location. 2 VBat Battery Supply Voltage (Negative). 3 RF1 Ring Feed (1): Connect to relay contact. See Figures 6 & 7. 4 RF2 Ring Feed (2). Connect to relay contact. See Figures 6 & 7. 5 RING 6 TIP Connects to the “Tip” or “A” lead of the telephone line. 7 I/C Internal Connection. 8 GNDBat 9 TF2 Tip Feed (2). Connect to TF1 for unbalanced ringing, see Figure 6. Connect to relay contact for balanced ringing, see Figure 7. 10 TF1 Tip Feed (1). Connect to TF2 for unbalanced ringing, see Figure 6. Connect to relay contact for balanced ringing, see Figure 7. 11 GNDA 12 VEE Negative Power Supply Voltage: Normally -5V. 13 VDD Positive Power Supply Voltage: Normally +5V. 14 VRR Ringing Relay Clamp Diode: Connect to relay coil and to relay supply voltage (Positive). For +5V relay, connect to VDD. 15 RC Ring Control (Input): A logic high will activate the Ring Relay Drive if SHK is high. 16 RD Ring Relay Drive (Output). Connect to relay coil. A logic low will activate the relay by sinking current from VRR through the relay coil. 17 LCA Loop Current Adjust (Input): Loop current is proportional to the voltage at this input. Normally connected to VRef 18 SHK Switch Hook Detect (Output): A logic low indicates an off-hook condition. 19 EGB Earth Ground Button (Output): A logic low indicates a grounded Ring lead condition. 20 VRef Voltage Reference (Output): Normally connected to LCA for default loop current. Connects to the “Ring” or “B” lead of the telephone line. Battery Supply Ground (Positive): Connect to System Ground Analog Ground: Normally connected to System Ground. MH88600 Preliminary Information Pin Description (Continued) Pin # Name Description 21 ZN0 Impedance Node 0. Connect to external network for impedance (Zin) setting. See Table 2 and Figure 8. 22 PG4 Programming 4 (Input). Used for programmable gain and for default gain. Used as 4Wire Receive Input for default gain. See Table 3 and Figure 4 and 5. 23 PG2 Programming 2 (Input). Used for programmable gain. Used with resistor for 4-Wire Receive Input. See Table 3 and Figure 4. 24 PG1 Programming 1 (Input). Used for programmable gain. See Table 3 and Figure 4. 25 PG3 Programming 3 (Input). Used for programmable gain and for default gain. See Table 3 and Figure 4 and 5. 26 TX 4-Wire Transmit Output: 27 ZN1 Impedance Node 1: Connect to other Impedance Nodes for impedance (Zin) setting, see Table 1. Or, connect to external network for impedance (Zin) setting, see Table 2 and Figure 8. 28 ZN2 Impedance Node 2: Connect to other impedances Nodes for impedance (Zin) setting. See Table 1. 29 ZN3 Impedance Node 3: As per ZN2. See Table 1. 30 ZN4 Impedance Node 4: As per ZN2. See Table 1 31 ZN5 Impedance Node 5: As per ZN2. See Table 1 32 ZN6 Impedance Node 6: As per ZN2. See Table 1 33 ZN7 Impedance Node 7: As per ZN2. See Table 1 34 ZN8 Impedance Node 8: As per ZN2. See Table 1 35 ZN9 Impedance Node 9: As per ZN2. See Table 1 36 ZN10 Impedance Node 10: As per ZN2. See Table 1 37 ZN11 Impedance Node 11: As per ZN2. See Table 1 38 ZN12 Impedance Node 12: As per ZN2. See Table 1 39 ZN13 Impedance Node 13: As per ZN2. See Table 1 40 ZN14 Impedance Node 14: Connect to external network for impedance (Zin) setting. See Table 2 and Figure 8. . 2-85 MH88600 Preliminary Information Functional Description Hybrid The BORSH Functions The 2-4 Wire Hybrid circuit separates the balanced full duplex signal at Tip and Ring of the telephone line into receive and transmit ground referenced signals at RX (receive) and TX (transmit) of the SLIC. The Hybrid also prevents the input signal at RX from appearing at TX. The degree to which the Hybrid prevents the RX signal from appearing at TX is specified at transhybrid loss. The MH88600 performs all of the BORSH functions; Battery Feed, Overvoltage Protection, Ringing, Supervision and Hybrid. Battery Feed The MH88600 provides the loop with constant DC current to power the telephone set. The voltage (negative) applied at the LCA pin determines the magnitude of the lop current. ILoop = 3.731 x VLCA mA (±2mA) Either the internal (VRef) or an external negative voltage reference may be used to set the loop current. Tip-Ring Drive Circuit The audio input ground referenced signal at RX is converted to a balanced output signal at Tip and Ring. The output signal consists of the audio signal superimposed on the DC Battery Feed Constant Current. The Tip-Ring Drive Circuit is optimised for good 2-Wire longitudinal balance. Short Circuit Protection Overvoltage Protection The MH88600 is protected from short term (20ms) transients (+250V) between Tip and Ring, Tip and ground, and Ring and Ground. However, additional protection circuitry may be needed depending on the regulatory requirements which must be met. Normally, simple external shunt protection as shown in Figures 6,7 and 8 is all that is required. Ringing The MH88600 has the capability to accommodate both balanced and unbalanced ringing sources. Refer to Figure 7 for the Balanced Ringing Circuit and Figure 6 for the Unbalanced Ringing Circuit. The MH88600 is protected from long term (infinite) short circuit conditions occurring between Tip and Ring, Tip and Ground, Ring and Ground, and Ring and Battery. The current is limited to the same value as the Constant Current Battery Feed. Programmable Line Impedance The MH88600’s Tip-Ring (Z in) impedance can be matched to the different impedances specified by different telephone administrations worldwide. This is accomplished by either linking specific pins as specified in Table 1, or by adding external components as shown in Figure 8 and Table 2. Programmable Transmit & Receive Gain Supervision The MH88600 is capable of detecting both Ground Button and Switch Hook conditions. The Ground Button detection (a logic low at the EGB output) operates when an imbalance in Tip and Ring DC current exceeds an internal threshold level caused by a grounded Ring Lead. Use of the EGB output is restricted to the off-hook condition of the telephone. The Switch Hook detection operates (a logic low at the SHK output) when the DC loop current exceeds an internal threshold level. The Ring Trip Detection Circuit prevents false offhook detection due to the current associated with the AC ringing voltage and also due to the large current transients when the ring voltage is switched in and out. In addition, the circuit prevents connection of the ringing source during off-hook conditions. 2-86 Transmit gain (TX to Tip-Ring) and Receive Gain (Tip-Ring to RX) can be programmed by connecting external resistors as indicated in Figure 4 and Table 3. Alternatively, the default Receive Gain of -4d Band Transmit Gain of +4dB can be obtained by connecting pins as shown in figure 5 and Table3. Note that RX is not a pin on the SLIC. The RX terminal will be either PG4 or the connection to the receive gain programming resistor RRX shown in Figure 4 and Figure 5. MH88600 Preliminary Information Loop Current (mA) VBat = -24V VBat =-48V 25 20 VBat = -24V VBat = -48V 15 Loop Detect Threshold 10 5 500 1000 Maximum Loop Length (Ω) 2000 1500 Figure 3a - Loop Current vs.Maximum Loop Current Maximum Loop Length (Ω) ILoop = 20mA 2000 1800 ILoop = 25mA 1600 1400 1200 1000 800 600 400 200 16 20 24 28 32 36 40 44 48 52 56 60 64 VBAT (V) Figure 3b - Maximum Loop Length vs Battery voltage 2-87 MH88600 Preliminary Information Absolute Maximum Ratings* - Voltages are with respect to AGND. Parameters 1 Sym Min. Max Units VDD -0.3 15 V VEE +0.3 -15 V VBat +0.3 -80 V VRR -0.3 40 V -55 125 °C 4 W DC Supply Voltages (GNDA = GNDBat) 2 Storage Temperature TS 3 Power Dissipation PD . * Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied. Recommended Operating Conditions Characteristics 1 Operating Supply Voltage Sym Min. Typ* Max Units VDD 4.75 5.0 5.25 V VEE -5.25 -5.0 -4.75 V VBat -72 -48 -24 V 5 24 V 70 °C VRR 2 Operating Temperature TOP 0 * Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing. 2-88 Comments MH88600 Preliminary Information DC Electrical Characteristics † Parameters 1 Supply Current Sym Min. IDD IEE IBat Typ* Max Units 8.5 5.0 12.0 10.0 4.8 mA mA mA 330 755 1556 mW mW mW Standby RLoop=1200Ω RLoop=0Ω VBat=-48V 22 30 mA mA LCA=-5.4V when RLoop-0Ω LCA=linked to VRef when RLoop=0Ω 2 Power Consumption PC 3 Constant Current Battery Feed ‡ ILoop ILoop 18 21 4 Operating Loop Resistance‡ RLoop 2000 800 1560 600 5 Off-Hook Detect Threshold SHKth 10 mA 6 GND Button Detect Threshold EGBth 10 mA 7 Ring GND Over-Current Protection 20 25 Ω Ω Ω Ω 32 41 mA 0.4 SHK & Low Level Output Voltage High Level Output Voltage VOL VOH 2.4 V V 9 EGB Sink Current Source Current IOL IOH 160 390 µΑ µΑ 10 RC Low Level Input Voltage High Level Input Voltage VIL VIH 4.0 High Level Input Current IIH 8 11 12 RD 13 14 VRef Sink Current IRLY Clamp Diode Current ICD Internal Reference 0.4 V V 1.5 mA 65 -7.4 Test Conditions RLoop=Open Cct, VBat = -48V VBat =-48V, ILoop=20mA VBat =-48V, ILoop=20mA VBat =-48V, ILLoop=25mA VBat =-48V, ILoop=25mA No Load VOL =0.8V VOH =-0.2V VIH = VDD mA -6.7 65 mA -6.0 V LCA linked to VRef * Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing. † DC Electrical Characteristics are over recommended operating conditions unless otherwise stated. ‡ See Figures 3a and 3b. 2-89 MH88600 Preliminary Information AC Electrical Characteristics† - Voltages are with respect to GNDA unless otherwise stated. Characteristics 1 Ringer Voltage 2 Ringer Equivalence No. 3 Ring Trip Detect Time 4 Input Impedance at PG4 Sym Min. Typ* Max Units VR 105 Vrms REN 5 200 5 Output Impedance at TX 6 Gain 2-Wire to TX: Fixed Gain Programmable Range Frequency Response Gain relative to Gain @ 1kHz 112 RRX kΩ ZTX 3 Ω A TX +3.5 RTX -12 +4 See Fig 6 ms ZRX at VRX Test Conditions See Fig 5 See Fig 4 +4.5 dB Input 1.0V at 1kHz See Fig 5 +6 dB See Figure 4 Input 1.0V AR TX 600Ω 2-Wire Impedance -0.75 -0.1 -0.3 -0.75 300Hz 600Hz and 2400Hz 3000Hz 3400Hz 7 Gain RX to 2-Wire: Fixed Gain Programmable Range Frequency Response Gain relative to Gain @ 1kHz ARX -4.5 RRX -12 -4 0.1 0.1 0.1 0.1 dB dB dB dB -3.5 dB Input 1.0V at 1kHz See Fig 5 +6 dB See Figure 4 Input 1.0V 600Ω 2-Wire Impedance ARRX -0.75 -0.1 -0.3 -0.75 300Hz 600Hz and 2400Hz 3000Hz 3400Hz 8 2-Wire Return Loss RL 9 2-Wire Input Impedance ZIN 10 Transhybrid Loss 11 Longitudinal Balance 12 Total Harmonic Distortion at TX at 2-Wire THL 20 18 0.1 0.1 0.1 0.1 26 dB dB dB dB dB dB Input 1.0V, 200Hz to 3.4kHz Input 1.0V, 3.4kHz to 4kHz See Table 1 20 40 52 41 dB Input 1.0V at 300Hz to 3400Hz at PG4 dB dB 40 - 3400Hz 3400-4000Hz % % Input 1.0V at 1kHz at 2-Wire Input 1.0V at 1kHz at PG4 THD 0.1 0.1 13 Common Mode Reject Ratio CMRR 14 Idle Channel Noise at TX (0dB gain) Idle Channel Noise at 2-Wire (0dB gain) Nc Np Nc Np 15 Power Supply Reject Ratio VDD VEE VBAT 16 Dial Pulse Distortion (SHK High to Low Time) PSRR td 1.0 1.0 40 CCITT 0.121 13 -78 11 -80 18 -73 16 -75 25 20 30 0.4 1 dBrnC dBrnp dBrnC dBrnp dB dB dB Ripple 1Vpp 1kHz Measure 2-Wire or TX ms 2-Wire loop at 1.2kΩ † AC Electrical Characteristics are over recommended operating unless otherwise stated. * Typical figures are at 25 C and are for design aid only: not guaranteed and not subject to production testing. 2-90 MH88600 Preliminary Information Table 1: Impedance Matching with Jumpers Zin Code Zin 2-Wire Input Impedance Administration ZN1 Link to: ZN8 Link to: --- ZN7 --- 1 600 600Ω 2 UK 370Ω + 620Ω // 310nF United Kingdom ZN6 ZN13 3 D 220Ω + 820Ω // 310nF Germany, Austria ZN5 ZN12 4 NA 350Ω + 1000Ω // 310nF Canada, USA ZN4 ZN11 5 F 210Ω +880Ω // 310nF France ZN3 ZN10 6 N 120Ω + 820Ω // 310nF Norway ZN2 ZN9 7 A 220Ω + 820Ω // 310nF Australia Use D Code Use D Code Note 1: The above impedances are as suggested by references: BS6305 (UK), REG3 (Australia), Proposed NET4, FCC Part 68 and recommendations by the various Administrations. Confirm your impedance requirements before proceeding. Note 2: All links to ZN1 should be as short as possible. Table 2: Impedance Matching with External Components Zin Code Zin 2-Wire Input Impedance Administration Rs Rp Cp 1 --- 600Ω + 2.16µF --- 6kΩ 1MΩ 216nF 2 ATT 900Ω + 2.16µF AT&T 9kΩ 1MΩ 216nF 3 NTT 600Ω + 1.0µF NTT 6kΩ 1MΩ 100nF 4 NZ 370Ω + (620Ω // 220nF) New Zealand 3.7kΩ 6.2kΩ 22nF Note 1: The above impedances are as suggested by reference CCITT Q.522. Confirm your impedance requirements before proceeding. Note 2: For Rs, Rp & C calculations, G is set to 10, R is set to 5656.8Ω, refer to figure 8 for additional information. Table 3: Transmit and Receive Gain Programming Transmit Gain (dB) RTX Resistor Value (Ω) +5.62 270k +4.0 No Resistor Results in 0dB overall gain when used with Mitel A-law codec (ie MT8965) +3.69 216k Results in 0dB overall gain when used with Mitel µ-law codec (ie MT8964) +2.1 180k 0.0 141k -3.0 100k Transmit Gain (dB) RTX Resistor Value (Ω) +6.6 33.1k +0.0 70.7k -3.0 100k -3.69 108k Results in 0dB overall gain when used with Mitel A-law codec (ie. MT8964) 4.0 No Resistor Results in 0dB overall gain when used with Mitel µ-law codec (ie MT8965) -6.5 150k Notes Notes Note 1: See Figures 4 and 5 for additional details. Note 2: Overall gain refers to the receive path of PCM to 2-Wire, and to transmit path of 2-Wire to PCM. 2-91 MH88600 Preliminary Information RTX 24 PG1 26 VTX TRANSMIT TX TX MH88600 25 PG3 22 PG4 PG2 23 VRX RECEIVE RX RRX Transmit Gain = VTx = RTX (kΩ)x0.007071 VTIP - RING GNDA 11 Receive Gain = VTIP - RING VRX = 70.71 RRX (kΩ) Note: PG3 and PG4 pins should be left open circuit. See Table 3. Figure 4 - Configuration of MH88600 for Gain Programming 24 PG1 26 TX V TX TRANSMIT TX MH88600 25 PG3 PG4 22 VRX RECEIVE RX PG2 23 VTX Transmit Gain = VTIP - RING = +4dB GNDA 11 Receive Gain = VTIP - RING VRX = -4dB Note: PG2 pins should be left open circuit. See Table 3. Figure 5 - Configuration of MH88600 for Default Gains 2-92 MH88600 Preliminary Information 34 39 RV1 10 ZN13 32 27 ZN1 ZN6 ZN8 TF1 9 PG3 TF2 TX 6 VX CODEC 5 RING PG4 4 22 VR RF2 K1 3 K1 16 RF1 RD EGB K1 15 17 20 13 RINGING CONTROL 12 C1 2 11 19 18 GNDBat GNDA VBat VEE VDD RC VRR VRef ~ +ve RELAY SUPPLY SHK LCA 14 RINGING GENERATOR 90VRMS 20Hz 26 MH88600 TIP TO MDF and SUBSCRIBER SET RV2 25 8 C2 -5V +5V RV1,RV2 - V150LA 150Vrms 13J (10/1000) C1,C2 - 10µ F/10V Electrolytic or Tantalum K1 - Relay E/M, 12V, 1Form C Figure 6- Typical Application Circuit 2-93 MH88600 Preliminary Information 30k 0.15W RV1 9 39 34 ZN13 TF1 ZN8 27 32 ZN1 ZN6 PG3 K1 10 TF2 6 TO MDF and SUBSCRIBER SET 5 TX TIP 4 3 K1 16 26 MH88600 RING PG4 RV2 25 22 RF2 RF1 RD 19 EGB K1 20Hz -48V 15 17 20 13 RINGING CONTROL 12 C1 2 11 18 GND Bat GNDA VBat VEE ~ 45VRMS 20Hz VRef ~ - RC + VRR VDD 45 VRMS +ve RELAY SUPPLY LCA 14 RINGING GENERATOR SHK 8 C2 -5V +5V Figure 7 - Application Circuit for Balanced Ringing 2-94 MH88600 Preliminary Information C1=C2=10µF, 10V Electrolytic or tantalum C3=1nF, 250V, 20% C3 is recommended to improve stability when RV1 used on loop lengths less than 500Ω total or used with active loads External Network Z R 40 21 27 ZN13 10 TF1 ZN1 ZN6 ZN8 PG3 TX Z=G x Zo R=565.68 x G Ω 6 G may be chosen to Zo suit preferred component values (useful for capacitive elements); resistive elements should have values in the range of 1k to 1MΩ. Typical values RV2 are G = 10 26 VX MH88600 TIP CODEC C3 5 4 RING PG4 22 VR RF2 K1 3 16 K1 RF1 RD EGB K1 14 VRR 15 17 20 13 RINGING CONTROL 12 C1 GNDA VBat VEE VDD VRef ~ +ve RELAY SUPPLY RC RINGING GENERATOR SHK LCA Set Rp=1MΩ for networks not specifying an Rp 2 11 19 18 GNDBat See Table 2 for external network examples. 90VRMS 20Hz 25 9 TF2 8 C2 -5V +5V Cp Rs Z = Rp Figure 8 - Using an External Network to Match any Zo 2-95 MH88600 Preliminary Information 2.0 (50.8) AAA AAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAAA AAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA 1.0 (25.4) Note 2 0.3 (7.62) Note 4 0.10 + 0.01 (2.54 + 0.25) AAAA AAAAAAAA AAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAAAAAA AAAA AAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAA MH88600 Note 1 0.020 + 0.002 (0.51 + 0.051) Notes: 1) Pin 1 not fitted. 2) Row pitch is to the centre of the pins. 3) All dimensions are typical and in inches (mm). 4) Seated Height 5) Not to scale Figure 9 - Mechanical Data 2-96 0.09 (2.3) 0.260 (6.6)