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For more information on Zarlink’s obsolete products and replacement product lists, please visit http://products.zarlink.com/obsolete_products/ MH88636-4 Central Office Interface Circuit Preliminary Information zFeatures • • • • • • • • • ISSUE 2 Loop Start Trunk Interface 900Ω Input Impedance 2-4 Wire Conversion On-Hook Reception Line State Detection Outputs: - Forward Loop - Reverse Loop - Switch Hook - Ringing Voltage Relay Driver Industrial Temperature Range option DIL and SMT versions Meets FCC part 68 Leakage Current Requirements Interface to Central Office for: • PABX • Key Telephone Systems • Channel Bank • Voice Mail • Terminal Equipment • Digital Loop Carrier • Optical Multiplexer FL RL SHK Ordering Information MH88636AD-4I 28 Pin DIL Package -40°C to 85°C MH88636AD-4 28 Pin DIL Package MH88636AS-4 28 Pin SMT Package 0°C to 70°C Description The Mitel MH88636-4 Central Office Trunk Interface circuit provides a complete analog and signalling link between audio switching equipment and a subscriber Line. The device is fabricated as a thick film hybrid technology for optimum circuit design and very high reliability for both commercial and industrial temperature changes. Applications RV January 1997 XLA XLB XLC XLD VCC VEE AGND Status Detection Line Termination & Impedance Matching TIP RING 2 - 4 Wire Hybrid Receive Gain Transmit Gain LRC LRD Loop Relay Driver RX TX Network Balance VRLY Figure 1 - Functional Block Diagram 2-287 MH88636-4 Preliminary Information XLB XLC IC 1 2 3 28 XLD 27 XLA 26 LRD TIP RING IC IC IC 4 5 6 7 8 9 25 24 VRLY 23 22 21 AGND 20 19 SHK RX IC IC IC IC 10 11 RL 12 FL 13 18 17 16 RV 14 15 VCC VEE LRC IC TX IC Figure 2 - Pin Connections Pin Description Pin # Name Description 1 XLB Loop Relay Contact B. Connects to XLA through the Loop Relay contacts (K1) when the relay is activated. 2 XLC Loop Relay Contact C. Connects to XLD through the Loop Relay contacts (K1) when the relay is activated. 3 IC Internal Connection. No connection should be made to this pin. 4 TIP Tip lead. Connects to the Tip lead of a Telephone Line. 5 RING 6 - 11 IC Internal Connection. No connection should be made to this pin. 12 RL Reverse Loop detect. In the on-hook status, a logic 0 output indicates that reverse loop battery is present. In the off-hook state, a logic 0 output indicates that reverse loop current is present. 13 FL Forward Loop Detect. In the on-hook status, a logic 0 output indicates that forward loop battery is present. In the off-hook state, a logic 0 output indicates that forward loop current is present. 14 RV Ringing Voltage Detect (Output). A logic 0 indicates that ringing voltage is across the Tip and Ring leads. 15, 16, 19 IC Internal Connection. No connection should be made to this pin. 17 TX Transmit (Output). 4 Wire ground (AGND) referenced analog output. 18 RX Receive (Input). 4 Wire ground (AGND) referenced analog input. 20 SHK Switch Hook (Output). A logic 0 indicates the presence of forward or reverse battery when LRC is logic 0 and the presence of forward or reverse loop current when LRC is logic 1. 21 LRC Loop Relay Control (Input). A logic 1 activates the Loop Relay Driver output (LRD). 22 VEE Negative Power Supply. -5V DC 23 AGND 24 VCC Positive Power Supply. +5V DC 25 VRLY Relay Supply Voltage. Typically +5V. Connects to the relay supply voltage. 2-288 Ring Lead. Connects to the Ring lead of a Telephone Line. Analogue Ground. 4 Wire ground. Normally connected to System Ground. MH88636-4 Preliminary Information Pin Description (continued) 26 LRD Loop Relay Drive (Output). Connects to the Loop Relay coil. When LRC is at a logic 1 an open collector output at LRD sinks current and energizes the relay. 27 XLA Loop Relay Contact A. Connects to XLB through the Loop Relay (K1) contacts when the relay is activated. 28 XLD Loop Relay Contact D. Connects to XLC through the Loop Relay (K1) contacts when the relay is activated. Functional Description The MH88636-4 is a Central Office Interface Circuit (COIC). It is used to correctly terminate a Central Office 2-Wire telephone line. The device provides a signalling link and a 2-4 Wire line interface between the telephone line and subscriber equipment. The subscriber equipment can include Private Branch Exchanges (PBX's), Key Telephone Systems, Terminal Equipment, Digital Loop Carriers and Wireless Local Loops. All descriptions assume that the device is connected as in the application circuit shown in Figure 3. termination across Tip and Ring. The device can be considered to be in an off-hook state and DC loop current will flow. The line termination consists of a DC resistance and an AC impedance. When LRC is at a logic 0, the Line Termination is removed from across Tip and Ring. An external Dummy Ringer should be permanently connected across Tip and Ring and under these conditions is the only load on the line. The device can be considered to be in an on-hook state and negligible DC current will flow. The Dummy Ringer is a series AC load of typically (17kΩ+330nF) which represents a mechanical telephone ringer and allows ringing voltages to be sensed. This load can be considered negligible when the line has been terminated. Isolation Barrier The MH88636-4 provides an isolation barrier which is designed to meet FCC Part 68 (November 1987) Leakage Current Requirements. External Protection Circuit An external Protection Circuit assists in preventing damage to the device and the subscriber equipment, due to over-voltage conditions. The type of protection required is dependant upon the application and regulatorary standards. In Figure 3 the protection is shown in block form. Further details should be obtained from the specific country’s regulatorary body. Suitable Markets The MH88636-4 has a selectable Input Impedance of 900Ω or 900Ω + 2.16µF. This makes it suitable primarily for North America or Brazilian markets. Line Termination When LRC is at a logic 1, LRD will sink current which energizes the Loop Relay (K1), connecting XLA to XLB and XLC to XLD. This places a line Depending on the Network Protocol being used the line termination can seize the line for an outgoing call, terminate an incoming call, or if applied and disconnected at the correct rate can be used to generate dial pulse signals. The DC line termination circuitry provides the line with an active DC load which is equivalent to a DC resistance of less than 300Ω, dependant upon the loop current. Ringing Equivalent Number The Ringing Equivalent Number (REN) is application specific. See the governing regulatory body specification for details. AC Input Impedance The Input Impedance (Zin) is the AC impedance that the MH88636-4 places across Tip and Ring in order to terminate the telephone line. It can be set to either 900Ω or 900Ω + 2.16uF by connecting an external impedance between XLA and XLD (Zext). To select a 900Ω Input Impedance, 1000Ω must be connected across XLA and XLD. 2-289 MH88636-4 To select a 900Ω + 2.16µF Input Impedance, 1000Ω + 360Ω//2.2uF must be connected across XLA and XLD. Preliminary Information system controller. The supervisory circuitry is capable of detecting: Ringing Voltage; Forward and Reverse loop battery; Forward and Reverse loop current; and Switch Hook. All connections should be kept as short as possible. Network Balance Impedance The MH88636-4’s Network Balance Impedance has been optimised for either of the two Input Impedances. • Ringing Voltage Detect Output (RV) The RV output provides a logic 0 when ringing voltage is detected across Tip and Ring. It toggles at the ringing frequency, typically going low 50ms after the ringing voltage is applied and remains low for 50 ms after ringing voltage is removed. • 2-4 Wire Conversion The device converts the balanced 2-Wire input, presented by the line at Tip and Ring, to a ground referenced signal at TX. This circuit operates with or without loop current; signal reception with no loop current is required for on-hook reception enabling the detection of Caller Line Identification (CLI) signals. Conversely the device converts the ground referenced signal input at RX, to a balanced 2-Wire signal across Tip and Ring. The 4-Wire side (TX and RX) can be interfaced to a filter/codec, such as the Mitel MT896X, for use in digital voice switched systems Forward Loop and Reverse Loop Detect Outputs (FL & RL) The FL output provides a logic 0 when either forward loop battery or forward loop current is detected, that is the Ring pin voltage is negative with respect to Tip pin voltage. The RL output provides a logic 0 when either reverse loop battery or reverse loop current is detected, that is the Tip pin voltage is negative with respect to Ring pin voltage. • The Switch Hook Detect (SHK) The SHK output is active if either forward loop or reverse loop current is detected, or if forward or reverse battery voltage is detected. Control InputS During full duplex transmission, the signal at Tip and Ring consists of both the signal from the device to the line and the signal from the line to the device. The signal input at RX, being sent to the line, must not appear at the output TX. In order to prevent this, the device has an internal cancellation circuit. The measure of attenuation is Transhybrid Loss (THL). Transmit and Receive Gain The Transmit Gain of the device is the gain from the balanced signal across Tip and Ring to the ground referenced signal at TX. It is set at 0dB. The Receive Gain of the device is the gain from the ground referenced signal at RX to the balanced signal across Tip and Ring. It is set at -2dB. Supervision Features Line Status Detection Outputs The MH88636-4 supervisory circuitry provides the signalling status outputs which are monitored by the 2-290 The MH88636-4 accepts a control signal from the system controller at the Loop Relay Control input (LRC). This energises the relay drive output Loop Relay Drive (LRD). The output is active low and has an internal clamp diode to VRLY. The intended use of this relay driver is to add and remove the Line Termination from across Tip and Ring, as shown in Figure 3. If this Control input and the Supervisory Features are used as indicated in Figure 3, Loop-Start Signalling can be implemented. Mechanical Data See Figure 9 and 10 for details of the mechanical specification. MH88636-4 Preliminary Information MH88636-4 +5V 4 Tip Protection Circuit TIP VCC Dummy Ringer 5 Ring TX 26 LRD RX 25 21 Loop Relay Control 1 27 K1 Zext LRC NOTES: 1) K1 Electro Mechanical 2 Form A 18 14 13 XLB FL XLA 2 XLC 28 17 Analog Out Analog In VRLY RV K1 C1 RING +5V K1 24 RL SHK 12 20 Ringing Detect Forward Loop Reverse Loop Switch Hook XLD AGND VEE 23 C2 22 2) Dummy Ringer is typically 17kΩ + 330nF 3) C1 and C2 are decoupling capacitors -5V Figure 3 - Typical LS Application Circuit 2-291 MH88636-4 Preliminary Information Absolute Maximum Ratings* Parameters 1 DC Supply Voltages 2 3 4 5 DC Ring Relay Voltage Storage Temperature Ringing Voltage Ring Trip Current Sym Min Max Units VCC VEE VRLY -0.3 0.3 -0.3 -55 7 -7 18 +125 130 180 V TS VRING ITR V ˚C Vrms mArms Comments 250ms 10% duty cycle or 500ms single shot * Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied. Recommended Operating Conditions Parameters 1 DC Supply Voltages 2 3 DC Ring Relay Voltage Operating Temperature Symbol Min Typ‡ Max Units VCC VEE VRLY TOP 4.75 -4.75 -40 5.0 -5.0 5.0 25 5.25 -5.25 15 85 V V V ˚C 0 25 70 ˚C Comments Industrial range MH88636AD-4I Commercial range MH88636A*-4 ‡ Typical figures are at 25˚C with nominally ±5V supplies and are for design use only. DC Electrical Characteristics† Characteristics 1 Supply Current 2 3 FL RL SHK RV 4 LRD 5 LRC 6 LRC Sym Min Typ‡ Max Units 4 3 35 mA mA mW V V IOH = 0.4mA mA mA V V µA µA VOL = 0.35V Power Consumption Low Level Output Voltage ICC IEE PC VOL -0.3 13 13 137 0.5 High Level Output Voltage VOH 2.4 5.25 Sink Current, Relay to VCC Clamp Diode Current Low Level Input Voltage High Level Input Voltage High Level Input Current Low Level Input Current IOL ICD VIL VIH IIH IIL 100 150 0.8 2.0 40 40 † Electrical Characteristics are over recommended operating conditions unless otherwise stated. ‡ Typical figures are at 25˚C with nominally ±5V supplies and are for design use only. 2-292 Test Conditions IOL = 4mA VIH = 5.0V MH88636-4 Preliminary Information Loop Electrical Characteristics† Characteristics 1 2 3 4 Ringing Voltage Ringing Frequency Operating Loop Current Off-Hook DC Resistance 5 Leakage Current (Tip-Ring to AGND) SHK & FL Threshold Tip-Ring (On-hook) Tip-Ring Current (Off-Hook) SHK & RL Threshold Tip-Ring (On-Hook) Tip-Ring Current (Off-Hook) 6 7 Symbol Min RV 20 16 16 Typ‡ Max Units 110 68 70 300 320 7 Vrms Hz mA Ω mArms 14 5 20 15 Vdc mA LRC = 0V LRC= 5V -14 -5 -20 -15 Vdc mA LRC= 0V LRC = 5V 260 Test Conditions @ 20mA @ 16mA @ 1000VAC † Electrical Characteristics are over recommended operating conditions unless otherwise stated . ‡ Typical figures are at 25°C with nominal ±5V supplies and are for design aid only. 2-293 MH88636-4 Preliminary Information AC Electrical Characteristics† Characteristics 1 2-wire Input Impedance 2 Return Loss at 2-wire Symbol Zin RL 3 4 5 6 Longitudinal to Metallic Balance Metallic to Longitudinal Balance Transhybrid Loss Gain (voltage) 2 wire to TX THL Relative Gains 7 11 12 13 14 15 20 Typ‡ Max 900 Ω 30 dB 58 58 53 51 dB dB dB dB 60 40 20 dB dB dB -0.25 -0.15 -0.25 0 0 0 +0.25 +0.15 +0.15 dB dB dB -2.25 -0.15 -0.25 -2 0 0 10 5 -1.75 +0.15 +0.15 dB dB dB kΩ Ω Input impedance at RX Output impedance at TX Signal Overload Level at 2-wire at TX Total Harmonic Distortion at 2-wire at TX Idle Channel Noise at 2-Wire at TX Power Supply Rejection Ratio at 2-wire and TX VCC VEE CMRR On-Hook Gain, 2-Wire to TX Relative to Off-Hook Gain 3.0 0 dBm dBm Test Conditions Programmed with ZEXT=1kΩ Test circuit as Fig 6 200-3400 Hz Zin = 900Ω Test circuit as Fig 7 200Hz 1000Hz 2000Hz 3000Hz-4000Hz Test circuit as Fig 8 200Hz - 1kHz 1kHz - 4kHz 200-4000Hz Test circuit as Fig 4 1000Hz 300Hz 3400Hz Test circuit as Fig 5 1000Hz 300Hz 3400Hz % THD < 5% Ref 900Ω @ 20mA THD 0.1 0.1 1.0 1.0 % % 11 13 16 16 dBrnC dBrnC Input 0.5V, 1kHz @ Rx Input 0.5V, 1kHz @ Tip-Ring NC PSRR Ripple 0.1V, 1kHz 25 25 50 40 -1 dB dB dB dB 0 1 † Electrical Characteristics are over recommended operating conditions unless otherwise stated . ‡ Typical figures are at 25°C with nominal ±5V supplies and are for design aid only. 2-294 Units Gain (voltage) RX to 2 wire Relative Gains 8 9 10 Min dB Test circuit as Fig 7 50Hz - 200Hz 200Hz - 4kHz Input 1000Hz @ 0.5V MH88636-4 Preliminary Information +5V -5V VCC VEE -V 10H 300Ω XLA 100uF XLB RING I = 25mA + XLC 17kΩ XLD ~ Vs = 0.5V 600Ω 330nF 100uF TX TIP + RX AGND 10H 300Ω Gain = 20 * Log (Vtx/Vs) Figure 4 - 2-4 Wire Gain Test Circuit +5V -5V VCC VEE -V 10H 300Ω XLA 100uF I = 25mA XLB RING + XLC XLD 17kΩ Z = 600Ω 330nF 100uF TX TIP RX + Vs = 0.5V ~ AGND 10H 300Ω Gain = 20 * Log (Vz/Vs) Figure 5 - 4-2 Wire Gain Test Circuit 2-295 MH88636-4 Preliminary Information -V +5V -5V VCC VEE 10H 300Ω XLA 100uF I = 25mA XLB RING 600Ω + XLC 368Ω XLD Vs = 0.5V 17kΩ V1 368Ω ~ 330nF 100uF TX TIP RX + AGND 10H 300Ω Return Loss = 20 * Log (V1\Vs) Figure 6 - Return Loss Test Circuit +5V -5V VCC VEE -V 10H 300Ω XLA 100uF XLB RING I = 25mA + XLC 368Ω XLD 17kΩ V1 Vs = 0.5V 368Ω 330nF 100uF TX TIP RX AGND + 10H 300Ω Long to Met Bal. = 20 * Log (V1\Vs) CMRR = 20 * Log (Vtx\Vs) - (2-4W Gain) Figure 7 - Longitudinal to Metallic Balance and CMRR Test Circuit 2-296 ~ MH88636-4 Preliminary Information +5V -5V VCC VEE -V 10H 300Ω XLA 100uF XLB RING I = 25mA + 368Ω XLC XLD Vs = 0.5V 17kΩ ~ 510Ω V1 330nF 100uF TX TIP RX 368Ω + AGND 10H 300Ω Met to Long Bal. = 20 * Log (V1\Vs) Figure 8 - Metallic to Longitudinal Balance Test Circuit 0.26 Max (6.6 Max) 0.260 +0.015 (6.6 +0.4) 0.08 Typ (2 Typ) 0.90 Typ* (22.9 Typ) * 0.100 +0.010 (2.54 +0.25) 0.95 Max (24.2 Max) 0.020 +0.005 (0.5 +0.12) *0.05 Typ (1.27 Typ) 1.42 Max (36.1 Max) Notes: 1) Not to scale 2) Dimensions in inches. (Dimensions in millimetres) 3) Pin tolerances are non-accumulative. 4) Recommended soldering conditions: Max wave solkder temp: 260˚C for 10 secs. * Dimensions to centre of pin. 1 Figure 9 - DIL Package Mechanical Data 2-297 MH88636-4 Preliminary Information 0.32 Max (8.13 Max) 0.89 Typ (22.6 Typ) 0.125 +0.015 (3.18 +0.38) 0.020 +0.005 (0.51 +0.13) *0.05 Typ (1.27 Typ) * 0.100 +0.010 (2.54 +0.25) 0.060 Typ (1.52 Typ) Notes: 1.01 Typ (29.5 Max) 1) Not to scale 2) Dimensions in inches. (Dimensions in millimetres) 1 3) Pin tolerances are non-accumulative. 4) Recommended soldering conditions: Max reflow temp: 235˚C for 10 secs. * Dimensions to centre of pin. 1.42 Max (36.1 Max) Figure 10 - SMT Package Mechanical Data 0.10 (2.54) 0.10 (2.54) Notes: 1) Not to scale 2) Dimensions in inches. (Dimensions in millimetres) 3) All dimensions are Typical 0.89 (22.6) 0.04 (1.02) 0.06 (1.52) Figure 11 - SMT Footprint 2-298 For more information about all Zarlink products visit our Web Site at www.zarlink.com Information relating to products and services furnished herein by Zarlink Semiconductor Inc. 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. 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