|
|
Número de pieza | PBL386112SHT | |
Descripción | Subscriber Line Interface Circuit | |
Fabricantes | Ericsson | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de PBL386112SHT (archivo pdf) en la parte inferior de esta página. Total 18 Páginas | ||
No Preview Available ! February 2000
PBL 386 11/2
Subscriber Line
Interface Circuit
Description
The PBL 386 11/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar inte-
grated circuit for use in DAML, FITL and other telecommunications equipment. The
PBL 386 11/2 has been optimized for low total line interface cost and a high degree
of flexibility in different applications.
The PBL 386 11/2 emulates a transformer equivalent dc-feed, programmable
between 2x25 Ω and 2x900 Ω, with short loop current limiting adjustable to max
65 mA.
A second lower battery voltage may be connected to the device to reduce short
loop power dissipation. The SLIC automatically switches between the two battery
supply voltages without need for external components or external control.
The SLIC incorporates loop current, ground key and ring trip detection functions. The
PBL 386 11/2 is compatible with loop start signalling.
Two- to four-wire and four- to two-wire voice frequency (vf) signal conversion is
accomplished by the SLIC in conjunction with either a conventional CODEC/filter or
with a programmable CODEC/filter, e.g. SLAC, SiCoFi, Combo II. The programmable
line terminating impedance could be complex or real to fit every market.
Longitudinal line voltages are suppressed by a feedback loop in the SLIC and the
longitudinal balance specifications meet Bellcore TR909 requirements.
The PBL 386 11/2 package are 28-pin PLCC and 28 pin SSOP.
DT
DR
TIPX
RINGX
HP
TS
VEE
AOV
VBAT2
VBAT
BGND
Two-wire
Interface
Ring Trip
Comparator
Ground Key
Detector
Line Feed
Controller
and
Longitudinal
Signal
Suppression
Off-hook
Detector
VF Signal
Transmission
Ring Relay
Driver
Input
Decoder and
Control
RRLY
C1
C2
C3
VCC
DET
PSG
LP
REF
PLC
PLD
AGND
VTX
RSN
VEE
Key Features
• Selectable overhead voltage principle
– All adaptive: The overhead voltage
follows 0.6 VPeak < signals < 5 VPeak.
– Semi adaptive: The overhead
voltage follows 2.5 VPeak < signals <
5 VPeak.
• Metering 1.6 Vrms
• High and low battery with automatic
switching
• Battery supply as low as -10V
• Only +5V in addition to GND
and battery (VEE optional)
• 35 mW on-hook power dissipation in
active state
• Long loop battery feed tracks VBat for
maximum line voltage
• 44V open loop voltage @ -48V battery
feed
• Constant loop voltage for line
leakage <5 mA
• On-hook transmission
• Full longitudinal current capability
during on-hook
• Programmable loop & ring-trip detector
threshold
• Ground key detector
• Analog temperature guard
• Silent polarity reversal
• Integrated Ring Relay Driver
PBL 386 11/2
Figure 1. Block diagram.
28-pin plastic PLCC and 28-pin SSOP
1
1 page Parameter
Four-wire to two-wire, g4-2
Four-wire to four-wire, g4-4
Insertion loss
Two-wire to four-wire, G2-4
Four-wire to two-wire, G4-2
Gain tracking
Two-wire to four-wire RLDC≤ 2kΩ
Four-wire to two-wire RLDC≤ 2kΩ
Noise
Idle channel noise at two-wire
(TIPX-RINGX)
Harmonic distortion
Two-wire to four-wire
Four-wire to two-wire
Battery feed characteristics
Constant loop current, ILConst
PBL 386 11/2
Ref
fig Conditions
6 relative to 0 dBm, 1.0 kHz. EL = 0 V
0.3 kHz < f < 3.4 kHz
f = 8 kHz, 12 kHz,
16 kHz
6 relative to 0 dBm, 1.0 kHz. EL = 0 V
0.3 kHz < f < 3.4 kHz
Min
-0.15
-1.0
-1.0
-0.15
Typ
-0.2
-0.3
Max
0.15
0
0
0.15
Unit
dB
dB
dB
dB
6 0 dBm, 1.0 kHz, Note 5
G2-4 = 20 • Log
VTX
VTR
,ERX = 0
6 0 dBm, 1.0 kHz, Notes 5, 6
G4-2 = 20 • Log
VTR
ERX
,EG = 0
6 Ref. -10 dBm, 1.0 kHz, Note 7
-40 dBm to +3 dBm
-55 dBm to -40 dBm
6 Ref. -10 dBm, 1.0 kHz, Note 7
-40 dBm to +3 dBm
-55 dBm to -40 dBm
-6.22 -6.02 -5.82 dB
-0.2 0.2 dB
-0.1 0.1 dB
-0.2 0.2 dB
-0.1 0.1 dB
-0.2 0.2 dB
C-message weighting
Psophometrical weighting
Note 8
7 12 dBrnC
-85 -78 dBmp
6 0 dBm, 1.0 kHz test signal
0.3 kHz < f < 3.4 kHz
-50 dB
-50 dB
13
ILProg
=
500
RLC
18 < ILProg < 65 mA
0.92 ILProg ILProg
1.08 ILProg mA
Figure 6.
Frequency response, insertion loss,
gain tracking.
1
ωC
<< RL, RL = 600 Ω
RT = 120 kΩ, RRX = 120 kΩ
C
TIPX
VTX
RL
VTR ILDC PBL 386 11/2
RT
EL RINGX RSN
RRX
E RX
VTX
5
5 Page PBL 386 11/2
Hybrid Function
The hybrid function can easily be imple-
mented utilizing the uncommitted amplifier
in conventional CODEC/filter combinations.
Please, refer to figure 10. Via impedance
ZB a current proportional to VRX is injected
into the summing node of the combination
CODEC/filter amplifier. As can be seen
from the expression for the four-wire to
four-wire gain a voltage proportional to VRX
is returned to VTX. This voltage is converted
by RTX to a current flowing into the same
summing node. These currents can be
made to cancel by letting:
VTX
RTX
+
VRX
ZB
=
0
(EL
=
0)
The four-wire to four-wire gain, G4-4, in-
cludes the required phase shift and thus
the balance network ZB can be calculated
from:
ZB
=
-
RTX
•
VRX
VTX
=
-
RTX
•
ZRX
ZT
•
ZT
αRSN
-
G2-4S
•
(
ZL
+
2RF)
G2-4S • ( ZL + 2RF)
When choosing RTX, make sure the
output load of the VTX terminal is (RTX//RT
in figure 13) > 20 kΩ.
If calculation of the ZB formula above
yields a balance network containing an
inductor, an alternate method is recom-
mended. Contact Ericsson Microelectron-
ics for assistance.
The PBL 386 11/2 SLIC may also be
used together with programmable CODEC/
filters. The programmable CODEC/filter
allows for system controller adjustment of
hybrid balance to accommodate different
line impedances without change of hard-
ware. In addition, the transmit and receive
gain may be adjusted. Please, refer to the
programmable CODEC/filter data sheets
for design information.
Longitudinal Impedance
A feed back loop counteracts longitudinal
voltages at the two-wire port by injecting
longitudinal currents in opposing phase.
Thus longitudinal disturbances will ap-
pear as longitudinal currents and the TIPX
and RINGX terminals will experience very
small longitudinal voltage excursions, leav-
ing metallic voltages well within the SLIC
common mode range.
The SLIC longitudinal impedance per wire,
ZLoT and ZLoR, appears as typically 20 Ω to
longitudinal disturbances. It should be not-
ed that longitudinal currents may exceed
the dc loop current without disturbing the vf
transmission.
Capacitors CTC and CRC
If RFI filtering is needed, the capacitors
designated CTC and CRC in figure 13, con-
nected between TIPX and ground as well
as between RINGX and ground, may be
mounted.
CTC and CRC work as RFI filters in con-
junction with suitable series impedances
(i.e. resistances, inductances). Resistors
RF1 and RF2 may be sufficient, but series
inductances can be added to form a sec-
ond order filter. Current-compensated in-
ductors are suitable since they suppress
common-mode signals with minimum influ-
ence on return loss. Recommended values
for CTC and CRC are below 1 nF. Lower
values impose smaller degradation on re-
turn loss and longitudinal balance, but also
attenuate radio frequencies to a smaller
extent. The influence on the impedance
loop must also be taken into consideration
when programming the CODEC. CTC and
CRC contribute to a metallic impedance of
1/(π•f•CTC) = 1/(π•f•CRC), a TIPX to ground
impedance of 1/(2•π•f•CTC) and a RINGX to
ground impedance of 1/(2•π•f•CRC).
AC - DC Separation Capacitor, CHP
The high pass filter capacitor connected
between terminals HP and RINGX p r o -
vides the separation of the ac and dc
signals. CHP positions the low end frequen-
cy response break point of the ac loop in the
SLIC. Refer to table 1 for recommended
value of CHP.
Example: A CHP value of 68 nF will
position the low end frequency response
3dB break point of the ac loop at 13 Hz (f3dB)
according to f3dB = 1/(2•π•RHP•CHP) where
RHP = 180 kΩ.
RFB
VTX
RTX
PBL
386 11/2 ZT ZB
RSN
Z RX
VT
Combination
CODEC/Filter
VRX
Figure 10. Hybrid function.
11
11 Page |
Páginas | Total 18 Páginas | |
PDF Descargar | [ Datasheet PBL386112SHT.PDF ] |
Número de pieza | Descripción | Fabricantes |
PBL386112SHS | Subscriber Line Interface Circuit | Ericsson |
PBL386112SHT | Subscriber Line Interface Circuit | Ericsson |
Número de pieza | Descripción | Fabricantes |
SLA6805M | High Voltage 3 phase Motor Driver IC. |
Sanken |
SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |