MITEL MH88622-3, MH88622-5, MH88622-1, MH88622-2 Datasheet

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MH88622

DUAL OPS SLIC

Preliminary Info rm atio n

Features

•Dual SLIC

• Ringing generation

• On-hook t rans missi on

• Transformerless 2-4 wire conversion

• Constan t c u rrent feed

• Battery Feed to the line

• Tip Ring reversal cap ability

• Over current pro tecti on

• Off-Hook detecti on

• Logic interface for SHK

, RC, LR, ESE, LCS

• Metering injection

•Wide V

operatin g range

Bat

• Minim um in sta lla tio n s pa ce

• ESE ramped output

Applications

•Pair Gain

•CT2

• Cordless local loops

ISSUE 3 April 1995

Ordering Information

MH88622 -1, -2, -3,-5 40 Pin SIL Package

0°C to 70°C

Description

The Mitel MH88622 is a Dual Subscriber Interface
Circuit which provides a complete interface between
the telephone lines a dual codec, requiring a dual rail
supply, battery and dc supply for ringing generation.
The functions provided by the MH88622 includes 2-4
Wire conversion, constant current line feed,
signalling and control. The SLIC manufactured using
thick film hybrid technology which offers high voltage
capability, reliability and high density resulting in a
significant area saving on the printed circuit board. A
complete C.O. type solution can be implemented
with minimal external components. Different variants
are provided to meet different country line
impedance, they are:

-1 220Ω + (820 Ω // 115nF)

-2 600Ω

-3 370Ω + (620 Ω // 310nF)

-5 200Ω + (680 Ω // 100nF)

LR1

TIP1

RING1

VX1

VR1

ESI1

ESE1

SHK1

Loop

Supervision

Line Drivers/

Feed

2-4 Wire

Conversion

VDD VEE AGND VBat DCRI RC1 RF1 RF2 RGV RG1 RC2

LCS1

Over Current

Protection &

Constant

Current Feed

Ring Generator

LCS2

Over Current

Protection &

Constant

Current Feed

Figure 1 - Functional Block Diagram

SHK2

Loop

Supervision

Line Drivers/

Feed

2-4 Wire

Conversion

LR2
TIP2
RING2

VX2
VR2
ESI2
ESE2

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MH88622 Preliminary Information

TIP1

RING1

VBAT

DCRI

GND
ESI1

ESE1

VR1

SHK1

LCS1

VX1
VEE

GND

VDD

LR1

RC1

NC

NC
RF1
RF2

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

RGV

RG1

NC
NC

RC2

LR2
VDD
GND

VEE

VX2

LCS2

SHK2

VR2

ESE2

ESI2
GND

DCRI

VBat

RING2

TIP2

Figure 2 - Pin Connections

Pin Description

Pin # Name Description

1TIP1Tip Lead. Connects to the “TIP” lead of subscriber line 1.

21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40

2RING1Ring Lead . Connects to the “RING” lead of subscriber line 1.
3V

BAT

Battery V oltage. Typically -48V dc is applied to this pin. This should be connected to pin 38
of the hybrid on the PCB.

4 DCRI DC Ringing Voltage Input. A continuous 120V dc is applied to this input to achieve

90Vrms ringing. This should be connected to pin 37 of the hybrid.
5GNDGround . This pin should be tied to pins 13, 28 & 36 on the PCB.
6ESI1External Signal Input (Input). A continuous signal should be applied to this pin which will

be switched to “Tip” and “Ring” of subscriber 1.
7ESE1External Signal Enable (Input). The external signal to the subscriber 1 is controlled by a

logic level applied to this pin.
8VR1Receive (Input). 4-Wire GND ref erenced audio input for sub scrib er 1.

9SHK1

Off Hook Indication (Outpu t). A logic low out put indicates when subscriber 1 equipmen t

has gone off hook.

10 LCS1 Loop Curr ent Set 1. Logic 1 gives I

= 40mA, Logic 0 gives I

Loop

Loop

= 25mA
11 VX1 Transmit (Output). 4-Wire, GND referenced audio output for subscriber 1.
12 VEE Negative Supply Voltage. -5Vdc. Connects to pin 29 of the hybrid on the PCB.
13 GND Ground . Return path for VDD, VEE, VBat & DCRI. This pin should be connected to pins 5,

28 & 36 of the hybrid on the PCB.
14 VDD Positive Supp ly Voltage. +5Vdc. Connect to pin 27 of the hybrid on the PCB.
15 LR1 Line Reversal. A logic 1 applied to LR1 will reverse the “Tip” and “Ring” to subscriber 1.

This pin has an internal pull down.
16 RC1 Ringi ng Con trol (Inpu t). A logic level applied to this pin enables ringing to be applied

across Tip and Ring of subscriber 1.

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Preliminary Information MH88622

Pin Description (Continued)

Pin # Name Description

17 NC No Connection. This pin should not be connected.
18 NC No Connection. This pin should not be connected.
19 RF1 Ring ing Fr equ ency Node 1 (Input). A capacitor is connected betwe en RF1 & RF2 and

determine s the frequency of the ringing generator.

20 RF2 Ring ing Fr equ ency Node 2 (Input). Two capacitors are connected between RF1& RF2

and from RF2 to AGND. This determines the frequency of the ringing generator.

21 RGV Ri ng ing Ga in Voltage. Connects to RG1 through a resistor to reduce the output ringing

voltage. When left open circuit output ringing volt age is 90Vrms.

22 RG1 Ringing Gain Node 1. Connects to RGV thro ugh a resistor to reduce the output ringing

voltage. When left open circuit output ringing volt age is 90Vrms.

23 NC No Connection. This pin should not be connected.

24 NC No Connection. This pin should not be connected.
25 RC2 Ringi ng Con trol (Inpu t). A logic level applied to this pin enables ringing to be applied

across Tip and Ring of subscriber 2.

26 LR2 Line Reversal. A logic 1 applied to LR2 will reverse the “Tip” and “Ring” to subscriber 2.

This pin has an internal pull do wn.

27 VDD Positive Supp ly Voltage. +5Vdc. This pin should be connected to pin 14 of the hybrid on

the PCB.

28 GND Ground . Return path for VDD, VEE, VBat & DCRI. This pin should be connected to pins 5,

13 & 36 of the hybrid on the pcb.

29 VEE Negative Supply Voltage

the PCB.
30 VX2 Transmit (Output). 4-Wire GND referenced audio inpu t for subscriber 2.
31 LCS2 Loop Curr ent Set 2. Logic 1 gives ILoop = 40m A, Logic 0 gives ILoop = 25mA.

32 SHK2

33 VR2 Receive (Input). 4-Wire GND referenced audio input for subscriber 2.
34 ESE2 External Signal Enable (Input). The external signal to subscriber 2 is controlled by a logic

35 ESI2 Exter nal Signal Input. A continuous signal should be applied to this pin which will be

36 GND Ground . This pin should be tied to pins 5, 13 & 28 on the PCB.
37 DCRI DC Ringin g Voltage Input. A continuous 120Vdc is applied to this input to achieve 90

Off Hook Indication (Outpu t). A logic high output indicat es wh en sub scriber 2 equi pme nt

has gone off hook.

level applied to this pin.

switched to “Tip” and “Ring” of subscriber 2.

Vrms ringing. This should be connected to pin 4 of the hybrid on the PCB.

. -5Vdc. This pin should be connected to pin 12 of the hybrid on

38 VBAT Battery Voltage. Typically -48V dc is applied to this pin. This should be connected to pin 3

of the hybrid on the PCB.
39 RING2 Ring Lead. Connects to the “Ring” lead of subscriber line 2.
40 TIP2 Tip Lead. Connects to the “Tip” lead of subscriber line 2.

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