2-159
Features
600 ohm input impedance
Externally selectable network balances
Transformerless 2-4 wire conversion
Programmable constant resistance feed
Off-hook and dial pulse detection
High immunity to externally induced longitudinal
currents
Auto ring trip
On-hook transmission (ANI) capability
Minimum protection circuitry required
Compatible with requirements of CDOT DOC/
FCC, CSA/UL,CCITT
Excellent power dissipation (SIL vertical
mounting)
Applications
On/Off-Premise PBX Line Cards
Central Office Line Cards
Description
The Mitel MH88620IN 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 MH88620IN 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.
Figure 3 - Functional Block Diagram
VBat
VDD
VEE
AGND
N1
N2
SHK
TRD
TF2
TF1
RING
TIP
RF2
RF1
LCA
LGND
TRC RGND
TX
GTX0
GTX1
RX
GRX0
GRX1
Z2
Z1
RRD
RNGC
VRLY
Matched
Feed
Resistors
Auto Ring
Trip
Test Relay
Driver
Driver
Circuitry
and
Speech
Circuit
Ring Relay
Driver
Loop
Current
Set
Switch-Hook
Threshold Set
Ring
Filter
Switch-Hook
Detect
2W/4W
conversion
Impedance
Network
Gain Adjust
ISSUE 3
April 1995
Ordering Information
MH88620IN 40 Pin SIL Package
0
C to 70
C
MH88620IN
C.O. SLIC
Preliminary Information
2-160
MH88620IN
Preliminary Information
Figure 2 - Pin Connections
Pin Description
Pin #
Name
Description
1
TIP
Tip Lead. Connects to the TIP lead of the subscriber line
2
RING
Ring Lead: Connects to the Ring lead of the subscriber line.
3
TF1
Tip Feed 1: Access point for balanced ringing. Normally connects to TF2.
4
TF2
Tip Feed 2: Access point for balanced ringing. Normally connects to TF1.
5
RF1
Ring Feed 1: Access point for balanced ringing. Normally connects to RF2.
6
RF2
Ring Feed 2: Access point for balanced ringing. Normally connects to RF1.
7
LGND
Battery Ground. V
BAT
return path. Connected to system's energy dumping ground.
8
LCA
Current Limit Set (Input): The current limit is set by connecting an external resistor as
shown in Table 5. For 70mA default current, this pin is tied to -5V.
9
V
Bat
Battery Voltage: Typically -48V dc is applied to this pin.
10
RS1
Ring Sense Resistor Connection 1. See Figure 7a.
11
RGND
Ring Driver Ground Connection.
12
VRLY
Relay Supply Voltage Connection
13
RRD
Ring Relay Drive (Output). Connects to ring relay coil
14
RNGC
Ring Relay Control (Input)
15
RS2
Ring Sense Resistor Connection 2. See Figure 7a
16
TRD
Test Relay Drive (Output): Connects to test relay coil.
17
TRC
Test Relay Control (Input).
18
AGND
Analog Ground: V
DD
and V
EE
.
return path
19
NC
No Connection: Reserved.
20
N1
Network Balance Node 1. An external network balance impedance can be connected
between N1 and AGND. See Fig 4. for complex impedances. N2 no connection.
21
N2
Network Balance Node 2. See Fig 4. N2 connects to GND for 600
balance. N1 no
connection.
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
N2
NC
Z1
Z2
TX
RX
GTX0
GTX1
GRX0
GRX1
NC
NC
NC
SHK
IC
IC
IC
IC
VEE
VDD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
TIP
RING
TF1
TF2
RF1
RF2
LGND
LCA
VBAT
NC
RGND
VRLY
RRD
RNGC
NC
TRD
TRC
AGND
NC
N1
2-161
Preliminary Information
MH88620IN
22
NC
No Connection. Reserved
23 Z1
Line impedance Node 1. Normally connects to Z2. See Fig. 3.
24
Z2
Line impedance Node 2. Normally connects to Z1. See Fig 3.
25
TX
Transmit (Output)
.
4-wire (AGND) referenced audio output.
26
RX
Receive (Input). 4-wire (AGND) referenced audio 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 adjustment.
29
GRX0
Receive Gain Node 0. Connects to GRX1 for 0dB gain
30
GRX1
Receive Gain Node 1. Connect to a resistor to AGND for receive gain adjustment
31
NC
No Connection. Reserved
32
NC
No Connection. Reserved.
33
NC
No Connection. Reserved.
34
SHK
Off-Hook Indication (Output). A logic low output indicates when the subscriber
equipment has gone Off-Hook.
35.38
IC
Internal Connection.
39
VEE
Negative Supply Voltage. -5V dc.
40
VDD
Positive Supply voltage. +5V dc
Pin Description (Continued)
Pin #
Name
Description
2-162
MH88620IN
Preliminary Information
Absolute Maximum Ratings
*
All voltages are with respect to GNDA unless otherwise stated.
* Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.
Recommended Operating Conditions
-
Voltages are with respect to GNDA unless otherwise stated
.
* Typical figures are at 25C and are for design aid only; not guaranteed and not subject to production testing.
Voltages specified are with respect to LGND.
DC Electrical Characteristics
*
* DC Electrical Characteristics are over recommended operating conditions unless otherwise stated.
Typical figures are at 25C with nominal 5V supplies and are for design aid only.
Parameter
Symbol
Min
Max
Units
1
Supply Voltages
LGND -V
Bat
V
DD -
GND
GND - V
EE
65
6
6
V
V
V
2
Storage Temperature
T
S
-40
+125
C
Characteristics
Sym
Min
Typ*
Max
Units
Comments
1
Operating Temperature
T
OP
0
70
C
2
Supply Voltages
V
Bat*
V
DD
V
EE
-44
4.75
-4.75
-48
+5.0
-5.0
-60
5.25
-5.25
V
V
V
Characteristics
Sym
Min
Typ
Max
Units
Test Comments
1
Operating Loop Current
Variation in Loop current
from nominal
I
Loop
I
Loop
17
16
2
70
mA
mA
mA
mA
R
Loop
= 0
, LCA = -5V
1500
2000
V
Bat
= -48V
2
Operating Current
Power Dissipation
I
Bat
I
DD
I
EE
PDo
PD1
2
15
15
2
250
mA
mA
mA
W
mW
R
Loop
= Open (On-hook)
On-Hook or Off-Hook
On-Hook or Off-Hook
Active
Stand-by/Idle
3
SHK
Low Level Output Voltage
High Level Output Voltage
V
OL
V
OH
3.7
0.5
V
V
I
OL
= 400
A
I
OH
= 40
A
4
RNGC
TRC
Low Level Input Voltage
High Level Input Voltage
V
IL
V
IH
2.4
0.8
V
V
5
Low Level Input Current
High Level Input Current
I
IH
I
IL
20
20
A
A
V
IH
= 5.0V
V
IL
= 0.0V
2-163
Preliminary Information
MH88620IN
AC Electrical Characteristics
*
* AC Electrical Characteristics are over Recommended Operating Conditions unless otherwise stated.
Typical figures are at 25C with nominal
5V supplies and are for design aid only.
Note:
Test Conditions use a transmit and receive gain set to 0dB default and a Z
in
value of 600
unless otherwise stated.
"Ref" indicates reference impedance which is equivalent to the termination impedance.
"Net" indicates network balance impedance.
Characteristics
Sym
Min
Typ
Max
Units
Test Comments
1
Analog Tx Gain (T-R to TX)
0
dB
Externally adjustable
2
Analog Rx Gain (RX to T-R)
0
dB
Externally adjustable
3
Ringing Capability
25
V
RMS
R
Loop
= 1400
Term. 6.8
F +200
4
On-hook Transmission
Signal input level
Gain
4
2.0
8
V
RMS
dB
V
Bat
= -48V
T-R load = 10
k min.
5
SHK Rise Time
Fall time
t
R
t
F
1
1
msec
msec
Dial Pulse Detection
6
2 Wire Termination Impedance
600
Adjustable
7
Off-Hook Detect Threshold
10
mA
8
2-Wire Return Loss
600
at T-R
20
26
20
dB
dB
dB
300-500Hz
500-2500Hz
2500-3400Hz
9
Longitudinal Balance
Longitudinal to Metallic
58
55
53
dB
dB
dB
2000Hz, 1000Hz
2000Hz, 3000Hz
3400Hz
10
Longitudinal Current Capability
40
mA
20mA per lead
11
Idle Channel Noise
Rx to T-R
T-R to Tx
N
CR
N
CX
8
12
dBrnC
dBrnC
12
Transhybrid Loss
Tx gain 0dB
Rx gain 0dB
THL
16
20
16
dB
dB
dB
300-500Hz
500-2500Hz
2500-3400Hz
13
Analog Signal Overload Level at
TIP and RING
4
dBm
T-R = 900
V
BAT
= -48V
14
Ringing Signal Voltage
70
80
90
V
RMS
15
Ringing Frequency
20
25
30
Hz
16
Ring Trip Delay
100
ms
17
Absolute Gain variation
-25
0
+.25
dB
0dBm at T-R, 1kHz
18
Relative Gain, reference to 1kHz
-2
0
+.2
dB
300-3400Hz
19
Power Supply Rejection Ratio
V
BAT
V
DD
V
EE
PSRR
24
24
24
30
30
30
dB
1kHz, 100mVpp
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