February 1999
PBL 386 10/2
Subscriber Line
Interface Circuit
Description
The PBL 386 10/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated
circuit for use in PBX, Terminal adapters and other telecommunications equipment.
The PBL 386 10/2 has been optimized for low total line interface cost and a high
degree of flexibility in different applications.
The PBL 386 10/2 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 10/2 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 10/2 package is 28-pin PLCC.
Key Features
• Selectable overhead voltage principle
– All adaptive: The overhead voltage
follows 0.6 V
Peak
< signals < 5 V
Peak
.
– Semi adaptive: The overhead voltage
follows 2.5 V
Peak
< signals < 5 V
Peak
.
• Metering 1.6V
rms
• 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 V
Bat
for
maximum line voltage
• 44V open loop voltage @ -48 V battery
feed
• Constant loop voltage for line
leakage <5 mA
• On-hook transmission
• Full longitudinal current capability
during on-hook
Ring Relay
Driver
RRLY
DT
DR
TIPX
RINGX
HP
TS
• Programmable loop & ring-trip detector
threshold
• Ground key detector
• Analog temperature guard
• Integrated Ring Relay Driver
Ring Trip
Comparator
Input
Decoder and
Control
C1
C2
C3
VCC
DET
Ground Key
Detector
PLC
AOV
VBAT2
VBAT
Off-hook
Detector
PLD
AGND
VTX
BGND
VF Signal
Transmission
RSN
VEE
Figure 1. Block diagram.
28-pin plastic PLCC
1
38 P B
6 L
10
/2
VEE
Two-wire
Interface
Line Feed
Controller
and
Longitudinal
Signal
Suppression
PSG
LP
REF
PBL 386 10/2
Maximum Ratings
Parameter
Symbol
Min
Max
Unit
Temperature, Humidity
Storage temperature range
Operating temperature range
Operating junction temperature range, Note 1
Power supply,
0°C
≤
T
Amb
≤
+70°C
V
CC
with respect to AGND
V
EE
with respect to AGND
V
Bat
with respect to BGND, continuous
V
Bat
with respect to BGND, 10 ms
V
Bat2
with respect to A/BGND
Power dissipation
Continuous power dissipation at T
Amb
≤
+70
°C
Ground
Voltage between AGND and BGND
Relay Driver
Ring relay supply voltage
Ring relay current
Ring trip comparator
Input voltage
Input current
Digital inputs, outputs
(C1, C2, C3, DET)
Input voltage
Output voltage (DET not active)
Output current (DET)
TIPX and RINGX terminals,
0°C < T
Amb
< +70°C, V
Bat
= -50 V
TIPX or RINGX current
TIPX or RINGX voltage, continuous (referenced to AGND), Note 2
TIPX or RINGX, pulse < 10 ms, t
Rep
> 10 s, Note 2
TIPX or RINGX, pulse < 1
µs,
t
Rep
> 10 s, Note 2
TIP or RING, pulse < 250 ns, t
Rep
> 10 s, Note 3
T
Stg
T
Amb
T
J
V
CC
V
EE
V
Bat
V
Bat
V
Bat2
P
D
V
G
-55
-40
-40
-0.4
V
Bat
-75
-80
V
Bat
+150
+110
+140
6.5
0.4
0.4
0.4
0.4
1.5
°C
°C
°C
V
V
V
V
V
W
V
V
-5
VCC
BGND +13
75 mA
V
DT
, V
DR
I
DT
, I
DR
V
ID
V
OD
I
OD
I
TIPX
, I
RINGX
V
TA
, V
RA
V
TA
, V
RA
V
TA
, V
RA
V
TA
, V
RA
V
Bat
-5
-0.4
-0.4
V
CC
5
V
CC
V
CC
30
V
mA
V
V
mA
-110
V
Bat
V
Bat
- 20
V
Bat
- 40
V
Bat
- 70
+110
2
5
10
15
mA
V
V
V
V
Recommended Operating Condition
Parameter
Symbol
Min
Max
Unit
Ambient temperature
V
CC
with respect to AGND
V
EE
with respect to AGND
V
Bat
with respect to BGND
V
Bat2
with respect to BGND
T
Amb
V
CC
V
EE
V
Bat
V
Bat2
0
4.75
V
Bat
-58
V
Bat
+70
5.25
-4.75
-10
-10
°C
V
V
V
V
Notes
1.
2.
3.
The circuit includes thermal protection. Operation above max. junction temperature may degrade device reliability.
A diode in series with the VBat input increases the permitted continuous voltage and pulse < 10 ms to -85 V.
A pulse
≤1µs
is increased to the greater of |-70V| and |VBat -40V|.
R
F1
and R
F2
≥
20
Ω
are also required. Pulse is supplied to TIP and RING outside R
F1
and R
F2
.
2
PBL 386 10/2
Electrical Characteristics
0
°C ≤
T
Amb
≤
+70
°C,
V
CC
= +5V
±5
%, V
EE
= -5V
±
5%, V
Bat
= -58V to -40V, R
LC
=18.7kΩ, (I
L
= 27 mA), Z
L
= 600
Ω,
R
LD
= 50 kΩ,
R
F1
, R
F2
= 0
Ω,
R
Ref
= 15kΩ, C
HP
= 68nF, C
LP
=0.33
µF,
R
T
= 120 kΩ, R
SG
= 24 kΩ, R
RX
= 120 kΩ, AOV- and V
Bat2
-pin not connected,
unless otherwise specified. Current definition: current is positive if flowing into a pin.
Ref
fig
Parameter
Conditions
Min
Typ
Max
Unit
Two-wire port
Overload level, V
TRO
Off-Hook, I
LDC
≥
10 mA
On-Hook, I
LDC
≤
5 mA
Input impedance, Z
TR
Longitudinal impedance, Z
LoT
, Z
LoR
Longitudinal current limit, I
LoT
, I
LoR
Longitudinal to metallic balance, B
LM
2
Active state
1% THD, Note 1
2.5
1.4
Z
T
/200
20
35
V
Peak
V
Peak
Ω/wire
mA
rms
/wire
dB
dB
Note 2
0 < f < 100 Hz
active state
12
IEEE standard 455-1985,ZTRX = 736
Ω
0.2 kHz < f < 1.0 kHz
53
1.0 kHz < f < 3.4 kHz
53
3
active state
0.2 kHz
≤
f
≤
1.0 kHz
1.0 kHz < f < 3.4 kHz
3
active state
0.2 kHz
≤
f
≤
1.0 kHz
1.0 kHz < f < 3.4 kHz
4
active state
0.2 kHz < f < 3.4 kHz
59
59
53
53
70
70
Longitudinal to metallic balance, B
LME
E
B
LME
= 20 • Log
Lo
V
TR
Longitudinal to four-wire balance, B
LFE
E
Lo
B
LFE
= 20 • Log
V
TX
Metallic to longitudinal balance, B
MLE
V
TR
B
MLE
= 20 • Log
V
Lo
70
70
dB
dB
70
70
dB
dB
40
58
dB
Figure 2. Overload level, V
TRO
, two-wire
port
R
L
V
TRO
C
TIPX
VTX
I
LDC
1 << R , R = 600
Ω
L
L
ωC
R
T
= 120 kΩ, R
RX
= 120 kΩ
PBL 386 10/2
RINGX
RSN
R
T
E
RX
R
RX
Figure 3. Longitudinal to metallic (B
LME
)
and Longitudinal to four-wire (B
LFE
)
balance
1
ωC
<< 150
Ω,
R
LR
= R
LT
= R
L
/2= 300Ω
TIPX
E
Lo
C
R
LT
V
TR
R
LR
RINGX
VTX
PBL 386 10/2
RSN
R
T
V
TX
R
RX
R
T
= 120 kΩ, R
RX
= 120 kΩ
3
PBL 386 10/2
Ref
fig
Parameter
Conditions
Min
Typ
Max
Unit
Four-wire to longitudinal balance, B
FLE
4
active state
E
RX
V
Lo
0.2 kHz < f < 3.4 kHz
|Z
TR
+ Z
L
|
r = 20 • Log
|Z
TR
- Z
L
|
0.2 kHz < f < 0.5 kHz
0.5 kHz < f < 1.0 kHz
1.0 kHz < f < 3.4 kHz, Note 3
active, I
L
= 0
active, I
L
= 0
active, I
L
= 0
B
FLE
= 20 • Log
40
58
dB
Two-wire return loss, r
25
27
23
- 1.2
V
Bat
+ 2.4
|V
Bat
+4.5| |V
Bat
+3.6|
TIPX idle voltage, V
Ti
RINGX idle voltage, V
Ri
|V
TR
|
Four-wire transmit port
(VTX)
Overload level, V
TXO
Off-hook, I
LDC
≥
10 mA
On-hook, I
LDC
≤
5 mA
Output offset voltage,
∆V
TX
Output impedance, z
TX
Four-wire receive port
(RSN)
Receive summing node (RSN) dc voltage
Receive summing node (RSN) impedance
Receive summing node (RSN)
current (I
RSN
) to metallic loop current (I
L
)
gain,α
RSN
Frequency response
Two-wire to four-wire, g
2-4
6
5
dB
dB
dB
V
V
V
Load impedance > 20 kΩ,
1% THD, Note 4
0.2 kHz < f < 3.4 kHz
I
RSN
= 0 mA
0.2 kHz < f < 3.4 kHz
0.3 kHz < f < 3.4 kHz
1.25
0.7
-60
5
60
20
V
Peak
V
Peak
mV
Ω
mV
Ω
ratio
GND +25
10
50
400
relative to 0 dBm, 1.0 kHz. E
RX
= 0 V
0.3 kHz < f < 3.4 kHz
f = 8.0 kHz, 12 kHz, 16 kHz
-0.15
-0.5
-0.1
0.15
0
dB
dB
TIPX
C
V
Lo
R
LT
V
TR
R
LR
RINGX
VTX
Figure 4. Metallic to longitudinal and
four-wire to longitudinal balance
1
<< 150
Ω,
R
LT
= R
LR
= R
L
/2 =300Ω
ωC
R
T
= 120 kΩ, R
RX
= 120 kΩ
R
RX
PBL 386 10/2
RSN
R
T
E
RX
C
R
L
I
LDC
E
L
TIPX
VTX
Figure 5. Overload level, V
TXO
, four-wire
transmit port
1
<< R
L
, R
L
= 600
Ω
ωC
R
T
= 120 kΩ, R
RX
= 120 kΩ
R
RX
PBL 386 10/2
RINGX
RSN
R
T
V
TXO
4
PBL 386 10/2
Ref
fig
Parameter
Conditions
Min
Typ
Max
Unit
Four-wire to two-wire, g
4-2
6
Four-wire to four-wire, g
4-4
Insertion loss
Two-wire to four-wire, G
2-4
6
relative to 0 dBm, 1.0 kHz. E
L
= 0 V
0.3 kHz < f < 3.4 kHz
f = 8 kHz, 12 kHz,
16 kHz
relative to 0 dBm, 1.0 kHz. E
L
= 0 V
0.3 kHz < f < 3.4 kHz
0 dBm, 1.0 kHz, Note 5
V
TX
G
2-4
= 20 • Log
,E
RX
= 0
V
TR
0 dBm, 1.0 kHz, Notes 5, 6
V
TR
G
4-2
= 20 • Log
,E
L
= 0
E
RX
Ref. -10 dBm, 1.0 kHz, Note 7
-40 dBm to +3 dBm
-55 dBm to -40 dBm
Ref. -10 dBm, 1.0 kHz, Note 7
-40 dBm to +3 dBm
-55 dBm to -40 dBm
C-message weighting
Psophometrical weighting
Note 8
-0.15
-1.0
-1.0
-0.15
-0.2
-0.3
0.15
0
0
0.15
dB
dB
dB
dB
6
-6.22
-6.02
-5.82
dB
Four-wire to two-wire, G
4-2
6
-0.2
0.2
dB
Gain tracking
Two-wire to four-wire R
LDC
≤
2 kΩ
6
-0.1
-0.2
-0.1
-0.2
7
-85
0.1
0.2
0.1
0.2
12
-78
dB
dB
dB
dB
dBrnC
dBmp
Four-wire to two-wire R
LDC
≤
2 kΩ
6
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, I
LConst
12
6
0 dBm, 1.0 kHz test signal
0.3 kHz < f < 3.4 kHz
500
R
LC
0.92 I
LProg
I
LProg
-50
-50
dB
dB
I
LProg
=
18 < I
LProg
< 65 mA
1.08 I
LProg
mA
Figure 6.
Frequency response, insertion loss,
gain tracking.
R
L
C
TIPX
VTX
1
<< R
L
, R
L
= 600
Ω
ωC
E
L
V
TR
I
LDC
PBL 386 10/2
RINGX
RSN
R
T
E
RX
V
TX
R
T
= 120 kΩ, R
RX
= 120 kΩ
R
RX
5
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