MH89792
E1Transceiver
Preliminary Information
Features
• Complet e primary ra te 20 48kb /s CEPT line
driver and re ceiver
• Onboard pul se tran sform ers for transm it and
receive
• Meets lates t E TSI requirement s (ET S I ETS 30 0
011 (NET 5))
• Inductorless clock recovery
• Loss of signal indication/ polarity selection
• Programmab le pol arit y of extra cted c lock &
receive data
• Single +5 V ope ration
• Compatible with all E1 framers
2
• Small footprint area (<330mm
)
Applications
• Primary rate ISDN network Interface
• Multiplexe r equ ipm ent
• Private Network links
• Isochrono us LA NS/WANS
ISSUE 3 April 1995
Ordering Information
MH89792-1 20 Pin SIL Package
MH89792-2 20 Pin SIL Package
MH89792-3 20 Pin SIL Package
0°C to 70°C
Description
The Mitel MH89792 is a low cost E1 line driver/
receiver with clock extraction requiring no external
components. There are three versions available:
MH8979 2- 1 fo r 120
MH89792-2 for 75
MH8979 2- 3 fo r 100
Ω twisted pair cable;
Ω co-axial links;
Ω digital twisted pair.
TxA
TxB
E2o
LOSP
CLKF/
CLKR
RxINV
RxA
RxB
LOS
RxD
VDD VSS
Line
Driver
Polarity
Selection
Clock/Data
Transmit
Isolation
Transform er
Clock
Recovery
Line
Receiver
EQUIPMENT SIDE
Figure 1 - Functional Blo ck Diag ram
6dB
Pad
Receive
Isolation
Transformer
LINE SIDE
TLA
TLB
RLA
RLB
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MH89792 Preliminary Information
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
CLKF
E2o
VDD
RxA
RxB
VSS
RxD
RxINV
/CLKR
LOS
LOSP
NC
RLA
RLB
TLA
TLB
NC
NC
NC
TxA
TxB
Figure 2 - Pin Connections
Pin Description
Pin # Name Description
1E2o2048kHz Extracted clock (Output). This clock is extracted by the device from the received
signal. It is used internally to clock in data received from RLA and RLB.
2V
D.C. Power (In pu t) +5V supply
DD
3RxAReceiver A (Output ). The bipolar CEPT signal received by the device at RLA and RLB
inputs is converted to a unipolar format and output at this pin. This pin should be connected
to the positive receive pin of the framer.
4RxBReceiver A (Output). This pin should be connect ed to the negati ve receive gain pin of the
framer and provides a signal of the same format as RxA.
5V
Ground (Input). D.C. power return path.
SS
6RxDReceiv ed Data (Outp ut) This unipolar return to zero format signal is the product of RxA
and RxB logically “OR” ed and is required by some framers.
7RxINVRxA/RxB inversion (Input). A logic low applied to this pin will invert the outputs RxA and
RxB. A logic high should be applied if no inversion is required.
8
CLKF/
CLKR
E2o phase selecti on is achieved by use of this pin. A logic low provides E2o with a
falling edge coinciding with the centre of the data bit. A logic high provides E2o with a rising
edge.
9
LOS
Loss of signal (Output). This pin goes low when 128 continuous zeros are received on the
RLA and RLB inputs. When RxINV and LOS
RxINV is high and LOS
is low RxA and RxB are forced low. LOS is reset when 64 ones are
are low RxA and RxB are forced high. When
received in two dual E1 framer periods.
10 LOSP Loss of signal Polarity (Input). A logic low applied to this pin will invert LOS. A logic high
should be applied when LOS
is required.
11 NC No connection. This pin is not fitted.
12 RLA Received Li ne A (In put). The A wire or Tip Connection of the E1 receive line should be
connected to this pin.
13 RLB Receive Line B (Input). The B wire or Ring connection of the E1 receive line should be
connected to this pin.
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