大卫 布拉特
2-145
®
Features
•900 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 TELEBRAS 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 MH88620BR 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 MH88620BR 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 1 - Functional Block Diagram
V Bat
V DD V EE
AGND
N1N2
SHK
TRD
TF2
TF1RING TIP RF2RF1LCA
LGND TRC RGND TX
GTX0GTX1RX GRX0GRX1Z2Z1RRD
RNGC VRLY Matched Feed Resistors
Auto Ring Trip T est 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 3April 1995
Ordering Information
MH88620BR 40 Pin SIL Package
0°C to 70°C
MH88620BR
C.O.SLIC
Preliminary Information
2-146
MH88620BR
Preliminary Information
Figure 2 - Pin Connections
Pin Description
Pin #Name Description
1TIP Tip Lead. Connects to the TIP lead of the subscriber line.2RING Ring Lead: Connects to the Ring lead of the subscriber line.
3TF1Tip Feed 1: Access point for balanced ringing. Normally connects to TF2. 4TF2Tip Feed 2: Access point for balanced ringing. Normally connects to TF1.5RF1Ring Feed 1: Access point for bal
anced ringing. Normally connects to RF2.6RF2Ring Feed 2: Access point for balanced ringing. Normally connects to RF1.7LGND Battery Ground. V Bat return path. Connected to system’s energy dumping ground.8LCA Current Limit Set (Input): The current limit is set by connecting an external resistor as shown in T able 5. For 70mA default current, this pin is tied to -5V.9V Bat Battery Voltage: Typically -48V dc is applied to this pin.10NC No Connection : Reserved.11RGND Ring Driver Ground Connection.12VRLY Relay Supply Voltage Connection .
13RRD Ring Relay Drive (Output). Connects to ring relay coil.14RNGC Ring Relay Control (Input) .15NC Reserved. No Connection.
16TRD Test Relay Drive (Output): Connects to test relay coil.17TRC Test Relay Control (Input).
18AGND Analog Ground: V DD and V EE . return path .19NC No Connection: Reserved.
20N1Network 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. An external network balance impedance can be connected between N2 an
d AGND. See Fig 4 N2 connects to GND for 900Ω balance.
N2NC Z1Z2TX RX GTX0GTX1GRX0GRX1NC NC NC SHK IC IC IC IC VEE VDD
TIP RING TF1TF2RF1RF2LGND LCA VBAT
IC RGND VRLY RRD RNGC REVC ESI ESE AGND NATT N1
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2122232425262728293031323334353637383940
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Preliminary Information
MH88620BR
Pin #Name Description
22
NC
No Connection. Reserved .
23 Z1Line impedance Node 1. Normally connects to Z2. See Fig. 3. 24Z2Line impedance Node 2. Normally connects to Z1. See Fig 3.25TX Transmit (Output). 4-wire (AGND) referenced audio output.26RX Receive (Input). 4-wire (AGND) referenced audio input.
27GTX0Transmit Gain Node 0. Connects to GTX1 for 0dB transmit gain.
28GTX1Transmit Gain Node 1. Connects to a resistor to AGND for transmit gain adjustment. 29GRX0Receive Gain Node 0. Connects to GRX1 for 0dB gain.
30GRX1Receive Gain Node 1. Connect to a resistor to AGND for receive gain adjustment.31NC No Connection. Reserved .32NC No Connection. Reserved.33NC No Connection. Reserved.
34SHK Off-Hook Indication (Output). A logic low output indicates when the subscriber equipment has gone Off-Hook.35.38IC Internal Connection.
39VEE Negative Supply Voltage. -5V dc.40
VDD
Positive Supply voltage. +5V dc
Pin Description (Continued)
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MH88620BR
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 25°C 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 25°C 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
6566V V V 2Storage T emperature
T S
-40+125
°C
Characteristics
Sym Min Typ*
Max Units Comments
金铸成
1Operating T emperature T OP 070°C 2
Supply Voltages
V Bat V DD V EE V RLY
-444.75-4.75
-
48+5.0-5.0570-605.25-5.25
V 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
1716
±2必可酮
70
mA mA mA mA
R Loop = 0Ω, LCA = -5V 1500Ω
2000Ω V Bat = -48V
2
Operating Current
Power Dissipation
I Bat I DD I EE
PDo PD1
215152250
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 Input Voltage High Level Input Voltage
V OL
V OH 3.7
0.5
V V I OL = 400µA I OH = 40µA
4RNGC TRC
Low Level Input Voltage High Level Input Voltage V IL V IH 2.4
0.8
温泉浴片V V 5
Low Level Input Current High Level Input Current
I IL I IH
2020
µA µA
V IL = 0.0V V IH = 5.0V
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Preliminary Information
MH88620BR
AC Electrical Characteristics *
*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.
Note: T est Conditions use a transmit and receive gain set to 0dB default and a Z in value of 900Ω unless otherwise stated. “Ref” indicates reference impedance which is equivalent to the termination impedance.“Net” indicates network balance impedance.
Characteristics
Sym
Min
薛万东
Typ ‡Max
Units Test Comments 1Analog Tx Gain (T-R to TX)0dB Externally adjustable 2Analog Rx Gain (RX to T-R)0
dB Externally adjustable 3Ringing Capability 25
V RMS
R Loop = 1400Ω
T erm. 6.8µF +200Ω4
On-hook Transmission Signal input level Gain
4
2.08V RMS dB V Bat = -48V
T-R load = 10Ωk min.5SHK Rise Time Fall time
t R t F
11msec msec Dial Pulse Detection 6 2 Wire T ermination Impedance 900ΩAdjustable 7Off-Hook Detect Threshold 10
mA 8
2-Wire Return Loss 900Ω at T-R Zin = 900Ω
900Ω + 2.16µF at T-R Zin = 900Ω
202620141814
dB dB dB dB dB dB
300-500Hz 500-2500Hz 2500-3400Hz 300Hz
600-2000Hz 3400Hz
9
Longitudinal Balance
Longitudinal to Metallic
585553
dB dB dB 2000Hz, 1000Hz 2000Hz, 3000Hz 3400Hz 10Longitudinal Current Capability 40
mA 20mA per lead
11
Idle Channel Noise
Rx to T-R T-R to Tx N CR N CX 812
dBrnc dBrnc
12
Transhybrid Loss Tx gain 0dB Rx gain 0dB
THL
162016
dB dB dB 300-500Hz 500-2500Hz 2500-3400Hz 1314Analog Signal Overload Level at TIP and RING 4dBm T-R = 900ΩV Bat = -48V
15Ringing Signal Voltage 708090V RMS 16Ringing Frequency 20
2530Hz 17Ring Trip Delay 100ms 18Absolute Gain variation
-250+.25dB 0dBm at T-R, 1kHz 19Relative Gain, reference to 1kHz -20
+.2
dB 300-3400Hz 20
Power Supply Rejection Ratio
V Bat V DD V EE
PSRR
242424
303030
dB
1kHz, 100mVpp
元器件交易网b2b
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MH88620BR
Preliminary Information
Note 1.Overall gain refers to the receive path of PCM to 2-Wire.Note 2 See Figure 2 for Application Circuit.
Note 1. Overall gain refers to the receive path of PCM to 2-Wire.Note 2. See Figure 2 for Application Circuit.
Graph 1 - I Loop /R Loop Characteristics
Transmit Gain (dB) 2-Wire to Tx 20log
(Tx/2-Wire)
RTX Resistor (1%)
Value (Ω)
Notes
+6.0No Resistor
+4.038.3k Results in 0dB overall gain when used with Mitel A-law codec (i.e. MT8965)
+3.732.4k
0.0
Connect GTX0 to GTX1
-3.0
5.49k -
6.0 3.32k -12.0
1.43k
Receive Gain (dB) Rx to 2-Wire 20log
(2-Wire/ Rx)
RRX Resistor (1%)
Value (Ω)
Notes
+6.0No Resistor 0.0Connect GRX0 to GRX1
+3.0 5.49k -3.7
4.87k -4.0
4.64k
Results in 0dB overall gain when used with Mitel A-law codec (i.e. MT8965)
1.43k
70
60
300
I Loop (mA)
Constant Voltage Region
R Loop (ohms)
15451k Ω
2k Ω
Constant Current Region
元器件交易网b2b
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