MITEL MH88622-1

MH88622

DUAL OPS SLIC
Preliminary Information
Features
ISSUE 3
April 1995
Ordering Information
•
Dual SLIC
•
Ringing generation
•
On-hook transmission
•
Transformerless 2-4 wire conversion
•
Constant current feed
•
Battery Feed to the line
•
Tip Ring reversal capability
•
Over current protection
•
Off-Hook detection
MH88622 -1, -2, -3,-5
0°C to 70°C
Description
•
Logic interface for SHK, RC, LR, ESE, LCS
•
Metering injection
•
Wide V Bat operating range
•
Minimum installation space
•
ESE ramped output
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:
Applications
•
Pair Gain
•
CT2
•
Cordless local loops
SHK1
-1
-2
-3
-5
Line Drivers/
Feed
VX1
VR1
ESI1
ESE1
2-4 Wire
Conversion
VDD VEE AGND
220Ω + (820Ω // 115nF)
600Ω
370Ω + (620Ω // 310nF)
200Ω + (680Ω // 100nF)
LCS2
LCS1
Loop
Supervision
LR1
TIP1
RING1
40 Pin SIL Package
SHK2
Loop
Supervision
Over Current
Protection &
Constant
Current Feed
Over Current
Protection &
Constant
Current Feed
Ring Generator
Line Drivers/
Feed
LR2
TIP2
RING2
2-4 Wire
Conversion
VX2
VR2
ESI2
ESE2
VBat DCRI RC1 RF1 RF2 RGV RG1 RC2
Figure 1 - Functional Block Diagram
2-173
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
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Figure 2 - Pin Connections
Pin Description
Pin #
Name
1
TIP1
2
RING1
3
VBAT
Battery Voltage. 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.
5
GND
Ground. This pin should be tied to pins 13, 28 & 36 on the PCB.
6
ESI1
External Signal Input (Input). A continuous signal should be applied to this pin which will
be switched to “Tip” and “Ring” of subscriber 1.
7
ESE1
External Signal Enable (Input). The external signal to the subscriber 1 is controlled by a
logic level applied to this pin.
8
VR1
Receive (Input). 4-Wire GND referenced audio input for subscriber 1.
9
SHK1
Off Hook Indication (Output). A logic low output indicates when subscriber 1 equipment
has gone off hook.
10
LCS1
Loop Current Set 1. Logic 1 gives ILoop = 40mA, Logic 0 gives ILoop = 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 Supply 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
Ringing Control (Input). A logic level applied to this pin enables ringing to be applied
across Tip and Ring of subscriber 1.
2-174
Description
Tip Lead. Connects to the “TIP” lead of subscriber line 1.
Ring Lead. Connects to the “RING” lead of subscriber line 1.
MH88622
Preliminary Information
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
Ringing Frequency Node 1 (Input). A capacitor is connected between RF1 & RF2 and
determines the frequency of the ringing generator.
20
RF2
Ringing Frequency 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
Ringing Gain Voltage. Connects to RG1 through a resistor to reduce the output ringing
voltage. When left open circuit output ringing voltage is 90Vrms.
22
RG1
Ringing Gain Node 1. Connects to RGV through a resistor to reduce the output ringing
voltage. When left open circuit output ringing voltage is 90Vrms.
23
NC
No Connection. This pin should not be connected.
24
NC
No Connection. This pin should not be connected.
25
RC2
Ringing Control (Input). 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 down.
27
VDD
Positive Supply 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. -5Vdc. This pin should be connected to pin 12 of the hybrid on
the PCB.
30
VX2
Transmit (Output). 4-Wire GND referenced audio input for subscriber 2.
31
LCS2
Loop Current Set 2. Logic 1 gives ILoop = 40mA, Logic 0 gives ILoop = 25mA.
32
SHK2
Off Hook Indication (Output). A logic high output indicates when subscriber 2 equipment
has gone off hook.
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
level applied to this pin.
35
ESI2
External Signal Input. A continuous signal should be applied to this pin which will be
switched to “Tip” and “Ring” of subscriber 2.
36
GND
Ground. This pin should be tied to pins 5, 13 & 28 on the PCB.
37
DCRI
DC Ringing Voltage Input. A continuous 120Vdc is applied to this input to achieve 90
Vrms ringing. This should be connected to pin 4 of the hybrid on the PCB.
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.
2-175
MH88622
Preliminary Information
Absolute Maximum Ratings *- All voltages are with respect to GNDA unless otherwise stated.
Parameter
Symbol
Min
Max
Units
1
Supply Voltages - Referenced to VSS (GND)
VEE
VDD
VDCRI
VBat
+0.3
-0.3
-0.3
-60
-15
+15
+180
0.3
V
V
V
V
2
Operating Temperature
TAMB
-40
+85
°C
3
Storage Temperature
TS
-55
+125
°C
* Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.
DC Electrical Characteristics
Characteristics
1
2
Operating Loop Current
S
U
P
P
L
Y
3
Operating Supply Current
(per Channel)
Sym
Min‡
Typ*
Max‡
Units
VEE
VDD
VDCRI
VBat
-4.75
4.75
110
-60
-5
5
120
-48
-5.25
5.25
160
-20
V
V
V
V
IEE
IDD
IDCRI
30
30
15
mA
mA
mA
IBat
5
mA
High Level Input Voltage LR,
RC, ESE, LCS
VIH
Low Level Input Voltage LR,
RC, ESE, LCS
VIL
0.5
V
High Level Input Current LR,
RC, ESE, LCS
IIH
700
µA
Low Level Input Current LR,
RC, ESE, LCS
IIL
10
µA
High Level Output Current
SHK
IOH
0.4
mA
Low Level Output Current
SHK
IOL
4
mA
High Level Output Voltage
SHK
VOH
Low Level Output Voltage
SHK
VOL
11
Constant Current Line Feed
ILoop
12
Maximum Operating Loop
RL
13
Power Consumption
PC
300
mW
4
5
I
N
P
U
T
S
6
7
8
9
10
O
U
T
P
U
T
S
4.5
V
25
* Typical figures are at 25°C with nominal +5V supplies and are for design aid only.
‡
Max & Min figures guaranteed over 0°C to 70°C only
2-176
On-hook
On-Hook
Ringing
(REN=1)
Idle
V
4.75
23
Test Comments
0.4
V
27
mA
500
1500
Ω
Ω
LCS = 0
@ 25mA -24V
@ 25mA -48V
inclusive of telephone
set
Excluding PBAT & PDCRI
MH88622
Preliminary Information
AC Electrical Characteristics*
Characteristics
1
Sym
Gain VR to 2-Wire
Min‡
Typ†
-0.2
0
Gain relative to Gain @ 1kHz
-6.2
Gain relative to Gain @ 1kHz
THL
22
5 Ringing Signal Voltage
40
6 Ringing Frequency
17
7 Ringing Capability
4
Input 1.0Vrms 1kHz @ VR,
Zload = Zin
300-3.4kHz
-5.8
dB
Input 3dBm 1kHz @ 2W
Zsource = Z in
300-3.4kHz
7.5
mA
30
dB
68
Hz
20
10 Longitudinal to Metallic Balance
-1 Variant
-2 Variant
-3 Variant
-5 Variant
Metallic to Longitudinal Balance
-2 Variant only
See Table 1
REN 1750Ω impedance @ 20Hz min.
dB
Ripple
0.1 VPP 1kHz
dB
Input 0.5 Vrms 1kHz across Tip
& Ring Zload = Zin
30
30
30
9 2-wire Return Loss
300-3.4kHz
Vrms Min 65Vdc differential between
DCRI & VBAT
PSRR
VBat
VDD/VEE
VDCRI
11 Input AC Impedance (2- wire)
-1 variant (220Ω + 820Ω // 115nF)
-2 variant (600Ω)
-3 variant (370Ω + 620Ω // 310nF)
-5 variant (200Ω + 680Ω // 100nF)
dB
+0.15
3 Off-Hook Detect Threshold
8 Power Supply Rejection Ratio
-6
Test Comments
+0.2
+0.15
2 Gain 2-wire to VX
4 Transhybrid Loss
Max‡ Units
35
40
55
53
58
53
46
40
46
dB
dB
dB
dB
dB
dB
dB
dB
Input 0.5Vrms
50-300Hz
300-1000Hz
1k-4kHz
200Hz to 1kHz
3kHz
300Hz to 3k4Hz
300Hz to 600Hz
600Hz to 3k4Hz
60
40
dB
dB
200Hz to 1kHz
1kHz to 4kHz
Ω
1kHz @ 2-wire
ZIN
600
900
700
823
12 Input Impedance @ VR
230
kΩ
13 Output Impedance @ VR
10
Ω
0.2
0.2
%
%
Input 4dBm @2-Wire
Input 1V at VR
60
dB
Input 0,5V, 1kHz
14 Total Harmonic Distortion
THD
at VX
at Tip & Ring
15 Common Mode Rejection
Ratio 2-Wire to VX
CMRR
16 Idle Channel Noise
40
NC
at VX
at 2-wire
17 On-Hook Transmission Signal
Input Level Gain
18 External Signal Output Level
dBrn
C
15
15
2.0
6
1.75
2.2
Vrms VBat = -48V
dB T-R load = 10kΩ min.
Vrms VBat = -48V
T-R load = 200Ω
2-177
MH88622
Preliminary Information
AC Electrical Characteristics* (Continued)
Characteristics
Sym
19 SHK Rise Time
Fall Time
Min‡
Typ†
tR
tF
20 Analogue Signal Overload Level
@ Tip & Ring
1
1
ms
ms
4
dBm
21 Ring Trip Delay
100
22 Outband Noise
23 Crosstalk
Max‡ Units
No
Channel 1 to 2
Channel 2 to 1
Test Comments
Dial Pulse
Detection
@ 1kHz
ms
-70
dB
Refer to BS6305 section 4.1.4 &
fig 3 for details of limits
-80
-80
dB
dB
@ 1kHz
* AC 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.
‡ Max and Min figures guaranteed over 0°C to 70°C only.
Notes: Impedance set to variant impedance
Test conditions uses a Zin value as specified by variant number.
Test conditions use a transmit and receive gain set to 0dB default and a Zin value of 600Ω unless otherwise stated.
.
VDCRI
VBat
+5V
VDD
VR1
VX1
VEE
CODEC
SUBSCRIBER 1
RC1
-5V
LR1
ESE1
GND
LINE
CONTROLLER
LOGIC
ESI1
SHK1
SUBSCRIBER 1
TIP1
SHK2
VR2
VX2
CODEC
SUBSCRIBER 2
RC2
RING1
LR2
TIP2
ESE2
ESI2
12/16kHz
SOURCE
DCRI
RING2
RGV
RG1
SUBSCRIBER 2
RF1
CF1
RF2
CF2
120VDC
SUPPLY
Figure 3 - Loop Start SLIC Configuration Application Circuit
2-178
MH88622
Preliminary Information
Functional Description
Two Wire Port Termination Impedance
The SLIC uses a Transformerless 2-4 Wire converter
for each subscriber which can be connected to a
CODEC to interface the 2-Wire subscriber loop to a
time division multiplexed (TDM), pulse code
modulated (PCM), digital link.
The Tip/Ring impedance (Zin) is fixed for each
variant.
Powering of the subscriber line is provided through
precision battery feed resistors on the hybrid. The
thick film hybrid circuit contains control, signalling
and status circuits which combine to provide a
complete solution simplifying the manufacture of line
cards.
The transmit and receive gain of the MH88622 is
internally set.
Approvals
FCC part 68, CCITT, DOS CS-03, UL 1459, CAN/
CSA-22.2 N0. 225-M90 and ANSI/EIA/TIA-464-A are
system level safety standards and performance
requirements. As a component of a system, the
MH88622 is designed to comply with the applicable
requirements of these specifications.
Battery Feed
The SLIC is designed for a nominal battery voltage
of -48 Vdc and can provide the constant feed current
for 1500Ω loop under this condition.
The interface circuit is designed to be operated up to
a maximum of -60V dc battery feed voltage without
damage, providing a minimum loop length capability
of 2000Ω.
There is also a function on the SLIC that provides for
Tip-Ring reversal.
Current Limit
Primary over current protection is inherent in the
current limiting feature of the battery feed circuit.
Transmit and Receive Gain
Internal Ringing Generator
The MH88622 offers an on board ringing generator
requiring only two external passive components and
a DC voltage source to produce a sine wave of
between 17Hz to 68Hz.
An internal signal is amplified by a user programmed
amount and is applied to Tip and Ring. The
programmable gain must be set using RGV and RG1
to ensure that distortion of the ringing signal is
minimised.
With V BAT = -48Vdc and VDCRI = +120Vdc and the
ringing voltage = 90Vrms RGV and RG1 should be left
open circuit. By adding an external resistor between
RGV and RG1 it is possible to reduce the ringing
voltage applied by the driver section to Tip and Ring.
The DC voltage source should be continuously applied
to the MH88622. The ringing voltage will only be
applied when the RC pin of the relevant subscriber is
activated.
Typ. Frequency
(Hz)
CF1, CF2
(nF)
17
100
25
68
35
47
50
33
Table 1 - Ring Generator Capacitor Selection
Current limiting is provided for both Tip and Ring
unbalanced conditions.
The maximum loop current limit is set internally on
the interface and current limiting does not affect the
longitudinal or the signal balance of the device. To
set ILoop to 40mA tie the LCS pin high (Logic 1), to
set ILoop to 25mA the LCS pin may be left open circuit
or tied low (Logic 0).
12-16kHz Meter Pulse
The MH88622 provides control of an external signal
path to the driver. A 12/16 KHz continuous signal
should be applied to the ESI pin. Control of the ESE
input allows the metering signal to be transmitted to
the line with a ramped up and down amplitude to
reduce noise on the line. Typical ramp time is 10mS.
2-179
MH88622
Preliminary Information
Off-Hook and Dial Pulse Detection
High Voltage Capability
The SHK pin goes low when e DC loop current
exceeds a specified level. The threshold level is
internally set by the bias voltage of the switch hook
detect circuit.
Inherent in the thick film process is the ability of the
thick film process dielectric strengths of greater than
1000 VAC or 1500 VDC. The thick film process
allows easy integration of surface mount
components such as the high voltage bi-polar power
transistor line drivers. This allows for simpler, less
elaborate and less expensive protection circuitry
required to handle high voltage transients and fault
conditions caused by lightening, induced voltages
and power line crossing.
Dial pulse can be detected by monitoring the
interruption rate at the SHK pin. These dial pulses may
need to be debounced by the systems software.
Ring Trip Detection
The interface permits detection of an Off-Hook
condition during ringing. If the subscriber set goes
Off-Hook when the ringing signal has been applied,
the DC loop current flow will be detected within
approx. 100msecs and the SHK output will go low.
The ringing is automatically disabled by the internal
hardware.
Longitudinal Balance
Precision laser trimming of resistors in the hybrids
ensures good overall longitudinal balance.
On Hook Transmission
The MH88622 provides for on-hook transmission
which supports features such as Automatic Number
identifications (ANI).
Loop Length
The MH88622 can accommodate loop length of up to
2000Ω
minimum
(including
the
subscriber
equipment).
The interface circuitry can operate in the presence of
induced longitudinal currents of up to 40mA rms at
60Hz.
T
PROTECTION
T
PTC
RESISTOR
5 Ohms
R
R
PTC
RESISTOR
5 Ohms
Figure 4 - Typical Protection Circuit
2-180
TISP2290
or
P2702AB
MH88622
Preliminary Information
4.2 + 0.03
0.25 Max
(6.4 Max)
Side View
(107 + 1)
0.95 Max
(24.13 Max
1
2 3
4
39 40
0.010 + 0.002
(0.25 + 0.05)
0.27 Max
(6.9 Max)
*
Notes:
1) Not to scale
2) Dimensions in inches).
3) (Dimensions in millimetres).
*Dimensions to centre of pin &
tolerance non accumulative.
0.05 + 0.02
(1.3 + 0.5)
*
0.05 + 0.02
(1.27 + 0.5)
0.020 + 0.005
(0.51 + 0.13)
0.180 + 0.02
(4.6 + 0.5)
0.100 + 0.010
(2.54 + 0.26)
Figure 5 - Mechanical Data
2-181
MH88622
Notes:
2-182
Preliminary Information