MITEL MH88615-1, MH88615-3, MH88615-7 Datasheet

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MH88615

ONS Subscriber Line Interface Circuit

Advance Information

Features

• ONS SLIC

•Variants

- 1 Germany

-3 UK

- 7 North America

• Transformerless 2W to 4W conversion

• Battery Feed to line

• Off-Hook and dial pulse detection

• Tip and Ring gro und ov er-cur rent p rotec tion

• Power Denia l

• Integral Ringing A m p li fier

• Programmable Loop Current

•Wide V

Operatin g Range

BAT

Applications

Line Interfac e for

• PABX

•Pair Gain Systems

• Satellite Co mm unicati on Sys tem s

• Key Telephone S ystem s

• Marine Syst em s

• Cordles s Loc al Loo p

ISSUE 1 April 1995

Ordering Information

MH88615-1 20 Pin SIL Package
MH88615-3 20 Pin SIL Package
MH88615-7 20 Pin SIL Package

0°C to 70°C

Descript io n

The Mitel MH88615 ONS SLIC provides a complete
interface between a switching system and a
subscriber loop. The functions provided by the
MH88615 include battery feed and integral ringing
amplifier feed to the subscriber line, 2W to 4W
conversion current feed, off-hook and dial pulse
detection. The device is fabricated as a thick film
hybrid in a 20 pin single-in-line package.

TIP

RING

PD

Power Denial

Tip &

Ring

Drivers

Current Feed

VBat

Constant

2-Wire to 4-W ire

Figure 1 - Block Diagram

DCRI

Ringing Control

Conversion

Loop

Supervision

RV

RC

VR

VX

VRef
CAP

SHK

2-139

MH88615 Advance Information

TIP

RING

NC

DCRI

LPGND

VBat

NC

VDD

AGND

VEE

RC
PD
NC

SHK

VR

VRef

CAP

VX

NC

RV

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

Figure 2 - Pin Description

Pin Description

Pin # Name Description

1TIPTi p Le a d. Connects to the “Tip” lead of subscriber line.
2 RING Ring Lead. Connects to the “Ring” lead of subsriber line.
3NCNo Con necti on. This pin may be use d for internal connecti o ns.
4 DCRI DC Ringing Voltage Input. A continuous 120 Vd c is applied to th is pin. This voltage is the

positive supply rail for the internal ringing am plif ier for subscriber line.

5LPGNDBattery Ground. V

dumping ground.

6 VBat Battery Voltage. Battery supply feed for subscriber line. Typically -48Vdc is applied to this

pin.
7NCNo Con necti on. This pin may be use d for internal connecti o ns.
8VDDPositive Supply Voltage. +5V dc supply rail.
9AGNDAnalogue Ground. V

10 VEE Negati ve Supp ly Voltage. -5V dc supply rail.
11 RC Ringing Control. This input enables the ringing voltage fe ed to Tip and Ring for subscriber

line.

12 PD Power Denial. A logic high will isolat e the batte ry voltage for Tip and Ring.
13 NC No Connecti on . This pin may be used for intern al connecti on s.
14 SHK Switch Hook Detect. A logic high indicates when subscriber line has gone off-hook.
15 VR Receive Signal. This is the 4 wire analogue signal received at subscriber ’ s set.
16 VRef Reference Voltage. A dc reference voltage is applied to this pin to set the constant current

feed to subscriber line. This pin may also be grounded for normal 25mA loop current.

17 CAP Ring Trip Filter Capacitor. A capacitor is normally connected from this pin to ground and

filters out low frequency ringing signals, preventing false off-hook conditions.

return path for subscriber line. Connects to the systems’s energy

Bat

and VEE return path.

DD

18 VX Transmit Signal. This is the 4 wire analogue signal transmit ted from subscriber ’s set.
19 NC No Connecti on . This pin may be used for intern al connecti on s.
20 RV Ringing Voltage. 1. 5 Vrms signal is injected to this pin.

2-140