MITEL MH88625 Datasheet



MH88625

DID/OPS SLIC

Preliminary Inf ormat ion

Features

• Programm able gain, ne twork bal anc e and
impedance

• Transforme rless 2-4 wire conve rsion

• Constant cu rren t with co nstan t volta ge fall back
for long loop capability

• Pin compa tible wit h MH8 8632 a nd MH8 86 28

• Unbalan ce detection (Tip, Ring ground sens in g)

• Auto ring trip

• On-Hook tran smissi on (A NI) cap ability

• Compatible with require men ts of CCI TT,
DOC/FCC and CSA /UL

• Excellent power dissipation (SIL vertical
mountin g)

• 12/16kHz meter pulse injection control

• Solid State TIP/RING reversals

Applications

• On/Off Premise PBX Line Cards

• DID (Direct Inward Dial) L ine Car ds

• Central Offic e Line C ard s

ISSUE 6 April 1995

Ordering Information

MH88625 40 Pin SIL Pa ckag e

0°C to 70°C

Descript io n

The Mitel MH88625 SLIC provides all of the
functions required to interface 2-wire off premise
subscriber loops to a serial TDM, PCM, switching
network of a modern PBX. The MH88625 is
manufactured using thick-film hybrid technology
which offers high voltage capability, reliability and
high density resulting in significant printed circuit
board area savings. A complete line card can be
implemented with very few external components.

RING

RF1
RF2

TIP

TF1

TF2

UD

RNGC
RGND

VRLY

LGND

VBat

Matched

Feed

Resistors

Unbalance

Detection

Ring
Relay
Driver

RRD

REVC Z900 Z600 Z1 Z2 GRX1 GRX0 RX GTX1 GTX0 TX

Tip/Ring

Reversal

Driver

Circuitry

And

Speech

Circuit

External

Signal

Input

ESI ESE

LCA

Loop

Current

Set

Impedance

Network

VDD

VEE

Switch-hook

Threshold Set

Switch-hook

Detect

2-4 Wire

Conversion

Gain Adjust

FIgure 1 - Functio nal Blo ck Diag ram

AGND

Ring

Filter

SHK

NS

N1

N2
NATT

2-183

MH88625 Preliminary Information

TIP

RING

TF1

TF2
RF1
RF2

LGND

LCA

VBat

IC

RGND

VRLY

RRD

RNGC

REVC

ESI

ESE

AGND

NATT

N1

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

N2

Z900

Z1
Z2

TX

RX
GTX0
GTX1

GRX0
GRX1

IC

Z600

NS

SHK

UD

IC
IC
IC

VEE

VDD

Figure 2 - Pin Connections

Pin Description

Pin # Name Description

1TIPTip Lead. Connects to the “Tip” lead of subscriber line.

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

2RINGRing Lead. Connects to the “Ring” lead of the subscriber line.
3TF1Tip Feed 1. Access point for balanced ringing. Norma lly connects to TF2.
4TF2Tip Feed 2. Access point for balanced ringing. Norma lly connects to TF1.
5RF1Ring Feed 1. Access point for balanced ringing. Normally connects to RF2 .
6RF2Ring Feed 2. Access point for balanced ringing. Normally connects to RF1 .
7LGNDBattery Ground. V

return path. Connected to system’s energy dumping ground.

Bat

8LCACurrent Limit Set (Inp ut). The current limit is set by connecting an external resisto r to

ground. For 30mA default cu rren t, this pin is tied to GND

9V

Battery Voltage. Typically -48Vdc is applied to this pin.

Bat

10 IC Internal Connection. This pin is internally connected and must be lef t open.
11 RGND Relay Driver Ground Connection.
12 VRLY Relay Supply Voltage Connection.

13 RRD
14 RNGC

Ring Relay Drive (Outpu t). Connects t o ring relay coil.
Ring Relay control (Inp ut). A logic low enable s the Ring Relay Drive (RRD) out put wh ich

activates the Ring Relay. The internal auto ring trip circuitry de-activates the relay drive

output upon detection of switch-hook.
15 REVC Reversal Control (Input). A logic high reverse the internal Tip and Ring connections.
16 ESI External Signal Input. 12/16kHz me ter pulse inpu t.
17 ESE External Signal Enable. 12/16kHz meter pulse enable .
18 AGND Analog Ground. V

2-184

and VEE return path.

DD

Preliminary Information MH88625

Pin Description (Continued)

Pin # Name Description

19 NATT Network Balance AT+T Node. Connects to N1 for a network balance impedance of AT&T

compromise (350Ω + 1kΩ // 210nF); the device’s input impedance must be set to 600Ω. This
node is active only when NS is at logic high. This node should be left open circuit when not
used.

20 N1 Network Balance Node 1 (Inp ut). 0.1 times the im peda nce betwee n pins N1 and N2 must

match the device’s input impedance, while 0.1 t ime s the impedance bet ween pins N1 and
AGND is the device’s network balance impedance. This node is active only when NS is at

logic high. This node may be terminated when not used (i.e., NS at logic low).
21 N2 Network Balance Node 2 (Outpu t). See N1 for description.
22 Z900 Line Impedance 900Ω Node. Connects to Z1 for a line impedance of 900Ω. This node

should be left open circuit when not used.
23 Z1 Line Im ped ance Node 1 (Input). 0.1 times the times the im pedance between pin s Z1 and

Z2 is the device’s line impedance. This node must always be connected.
24 Z2 Line Impedance Node 2 (Output). 0.1 times the times the impedance between pins Z1 and

Z2 is the device’s line impedance. This node should be left open circuit when not used.
25 TX Transmit (Output). 4-Wire (AGND) referenced audio output .
26 RX Receive (Inpu t). 4-Wire (AGND) referenced audi o input.
27 GTX0 Transmit Gain Node 0. Connects to GTX1 for 0dB transmit gain.
28 GTX1 Transmit Gain Node 1. Connects to a resistor to AGND for transmit gain adjustm ent.
29 G RX 0 Receive Gain Node 0. Connects to GRX1 for 0dB gain.
30 G RX 1 Receive Gain Node 1. Connects to a resistor to AGND to receive gain adjustment.
31 IC Internal Connection . This pin is internally connected and must be left open.
32 Z600 Line Impedanc e 600

Ω Node (Output). Connects to Z1 for a line impedance of 600Ω. This

pin should be left open circuit when not used.
33 NS Network Balance Settin g (Input). The logic level at NS selects the network balance

impedance. A logic 0 enables an internal balance equival ent to the input impedance (Zin).

While a logic 1 enables an external balance 0.1 tim es the impedance bet ween pins N1 and

AGND balanced to 0.1 times the im pedance between pins N1 and N2. Th e impe dance

between N1 and N2 must be equivalent to 10 times the input impedance (Zin).
34 SHK

Off-Hook Indication (Output). A logic low output indicate s when the subscriber equipment

has gone Off-Hook.
35 UD

Unbalance Detect (Output). A log IC low output indicat es when the DC current flow in the

Tip and Ring leads is unbalanced, indicating that the subscriber equipment has grounded

the Ring lead.

36,37,38

39 V
40 V

IC Internal Connection. These pins are internally connected and m ust be left open

Negative Supply Voltage. -5V dc.

EE

Positive Supply Voltage. +5V dc.

DD

2-185

MH88625 Preliminary Information

Absolute Maximum Ratings*

Parameter Sym Min Max Units Comments

1 Supply Voltage V

V

-V

2 Storage Temperature T

* Exceeding these values ma y cause perm anen t dama ge. Functi onal operati on und er these cond ition s is not implied.

Bat
DD

EE

S

+0.3

-0.3

+0.3

65

6
6

-40 +125 °C

V

With respect LG ND
V
V

Recommended Operating Conditions

Parameter Sym Min Typ* Max Units Comments

1 Supply Voltage V

2 Operating Temperature T

* Typical figures are at 25

° C with nominal + 5V supplies for design aid only.

Bat

V

DD

V

EE

OP

-44

4.75

-4.75

-48

+5.0

-5.0

-60

5.25

-5.25

20 0 70 °C

V
V
V

DC Electrical Characteristics

Characteristi cs Sym Min Typ* Max Units Test Conditions

1 Operating Loop Current

Var in loop current from nominal

2 Operating Currents I

3 Power Dissipation PD

4SHK

UD

5ESENSLow Level Input Voltage

6ESENSHigh Level Input Current

‡ DC Electrical Characteristics are over recommended operating conditions unless otherwise stated.
* Typical figures are at 25°C with nominal

Low Level Output Voltage
High Level Output Voltage

High Level Input Voltage

Low Level Input Current

‡

I

Loop

I

Loop

I

Loop

I

Loop

Bat

I

Bat

I

DD

I

EE

PD

V
V

V
V

I

I

OL
OH

IL

IH

IH

IL

16

0
1

3.7

2.4

+5V supplies and are for design aid only.

30

4

+

32

2

25
25

2

300

45 mA

mA
mA

mA
mA

mA
mA

mA

W

mW

0.5 V

0.8 V

20
20

µA
µA

R
2300Ω V

R
GND

R
LCA=GND
R
Hook)
On-Hook or Off-Hook
On-Hook or Off-Hook

Active
Standby/Idle

I

V

I

V

VIH=5.0V
V

=0Ω

Loop

Bat

=0Ω, LCA -

Loop

=0 (Off-Hook),

Loop

= open (On-

Loop

= 400µ A

OL

= 40µA

OH

=0.0V

IL

=-48V

2-186

Preliminary Information MH88625

AC Electrical Characteristics

‡

Characteristics Sym Min Typ* Max Units Test Conditions

1 TX Gain 0 dB ext ernal l y adju st able
2 RX Gain 0 dB externally adjustable
3 Ringing Capability 5 REN
4 On-Hook Transmission

V

Signal Input Level

2.0 V

Gain 6

5 External Signal Output Level 1.75 2.25 V

rms

dB

rms

=-48V

Bat

T-R load = 10kΩ min.
V

= -48V, T-R load=

Bat

200Ω LCA=0V, Zo-600Ω,
Gain=0 dB

6SHK

Rise Time

Fall time

7 2-Wire Termination

Impedance

t

R

t

F

1
1

600/

900

ms
ms

Ω

Dial Pulse De te c ti on

Selectable
8 Off-Hook Detect Threshold 10 mA
9 2-Wire Return Loss 20

20
20

dB
dB
dB

300 to 500Hz

500 to 2500Hz

2500 to 3400Hz

10 Longitudi nal B alance

Longitundinal to Metallic

Metallic to Longit udinal

11 Longitudinal Current

58
53

dB
dB

40 mA 20mA per lead

200-1000Hz

3400Hz

Capability

12 Idle channel Noise

Rx to T-R

T-R to Tx

N

CR

N

CX

8

12 dBrnC

dBrnC
13 Transhybrid Loss THL 22 40 dB 200-3400Hz
14 Unbalanced Detect Threshold I

UB

10 mA

15 Analog Signal Overload Level

at Tip and Ring 4 dBm

T-R=600Ω, VBat=-4 8V

16 Ringing Signal Voltage 90 Vrms

17 Ringing Frequency 17 33 Hz
18 Ring Trip Delay 100 ms
19 Absolute Gain, Variation +
20 Relative Gai n, refere nce to

0.1 dB 0dB at T-R, 1kHz

+

0.05 dB 300-3400Hz

1kHz

21 Power supply Rejection Ratio

V
V

V

‡ AC Electrical Characteristics are over recommended operating conditions unless otherwise stated.
* Typical figure are at 25°C with nominal +
Notes: Impedance set by external network of 600Ω or 90 0Ω default.
External network for test purposes consists of 2200Ω + 820 0Ω // 11.5nF be twe en pins Z1 and Z2, the equivalent Z
the impedance and is equivalent o 220Ω+820Ω // 115nF.
Test condition uses a Z
Test cond ition s use a transmit and receive gain set to 0dB default and a Z
“Ref” indicates reference impedance which is equivalent to the termination impedance.
“Net” indicates ne two rk bala nce impe dance.
Refer to Table 1, 2 for TX, RX gain adjust ment .

value of 600Ω, 900Ω and the above external network.

in

PSRR

Bat
DD

EE

5V supplies and are for desig n aid only.

24
24
24

value of 600Ω unless otherwise stated.

in

dB 1kHz, 100mVpp

has 1/10

in

th

2-187