Preliminary
February 2000
PBL 386 61/2
Subscriber Line
Interface Circuit
Description
The PBL 386 61/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated
circuit for use in Central Office, MUX and other telecommunications equipment. The
PBL 386 61/2 has been optimized for low total line interface cost and a high degree of
flexibility in different applications.
The PBL 386 61/2 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 and ring trip detection functions. The
PBL 386 61/2 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 61/2 package is 28-pin PLCC.
Key Features
• Selectable overhead voltage principle
– All adaptive: The overhead voltage
follows 0.6 V
Peak
< signals < 6.2 V
Peak
.
– Semi adaptive: The overhead voltage
follows 3.1 V
Peak
< signals < 6.2 V
Peak
.
• Metering 2.2 V
rms
.
• High and low battery with automatic
switching
• Battery supply as low as -10 V
• Only +5 V in addition to GND
and battery (VEE optional)
• 39 mW on-hook power dissipation in
active state
• Long loop battery feed tracks V
Bat
for
maximum line voltage
• 44 V 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
• Programmable loop & ring-trip detector
threshold
• Analog temperature guard
DT
DR
TIPX
RINGX
HP
TS
Ring Trip
Comparator
Input
Decoder and
Control
C1
C2
C3
VCC
DET
Ground Key
Detector
VEE
Two-wire
Interface
REF
PLC
AOV
VBAT2
VBAT
Off-hook
Detector
PLD
AGND
VTX
BGND
VF Signal
Transmission
RSN
VEE
28-pin plastic PLCC
Figure 1. Block diagram.
1
38 PB
6 L
61
/2
Line Feed
Controller
and
Longitudinal
Signal
Suppression
PSG
LP
PBL 386 61/2
Maximum Ratings
Parameter
Preliminary
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, 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
Bat2
+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
Maximum supplied 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
Preliminary
Electrical Characteristics
PBL 386 61/2
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
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.
Parameter
Ref
fig
Conditions
Min
Typ
Max
Unit
Two-wire port
Overload level, V
TRO
,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
3.1
1.4
35
V
Peak
V
Peak
Ω/wire
mA
rms
/wire
dB
dB
Note 2
Z
T
/200
0 < f < 100 Hz
20
active state
28
IEEE standard 455-1985, ZTRX = 736
Ω,
active state
0.2 kHz < f < 1.0 kHz
55
1.0 kHz < f < 3.4 kHz
55
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 < 3.4kHz
61
61
55
55
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
dB
dB
dB
dB
40
dB
Figure 2. Overload level, V
TRO
, two-wire
port
1 << R , R = 600
Ω
L
L
ωC
R
T
= 120 kΩ, R
RX
= 120 kΩ
C
TIPX
VTX
R
L
V
TRO
I
LDC
PBL 386 61/2
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 61/2
RSN
R
T
V
TX
R
RX
R
T
= 120 kΩ, R
RX
= 120 kΩ
3
PBL 386 61/2
Ref
fig
Preliminary
Conditions
Min
Typ
Max
Unit
Parameter
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
dB
Two-wire return loss, r
25
27
23
- 1.5
V
Bat
+ 2.7
V
Bat
+4.2
1.55
0.7
-60
5
TIPX idle voltage, V
Ti
RINGX idle voltage, V
Ri
V
TR
Four-wire transmit port
(VTX)
Overload level, 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
V
Peak
V
Peak
mV
Ω
mV
Ω
ratio
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
60
20
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 61/2
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 61/2
RINGX
RSN
R
T
V
TXO
4
Preliminary
Parameter
Ref
fig
Conditions
Min
Typ
PBL 386 61/2
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
G
2-4
= 20 • Log
TX
,E
RX
= 0
V
TR
0 dBm, 1.0 kHz, Notes 5, 6
V
G
4-2
= 20 • Log
TR
,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
≤
2kΩ
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
≤
2kΩ
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
I
LProg
= 500
R
LC
18 < I
LProg
< 65 mA
0.92 I
LProg
I
LProg
-50
-50
dB
dB
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 61/2
RINGX
RSN
R
T
E
RX
V
TX
R
T
= 120 kΩ, R
RX
= 120 kΩ
R
RX
5
