Le79489
Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
I
Ideal for low power sensitive applications
I
Low standby power (normal and reverse)
I
Automatic on-chip battery switching
I
On-chip thermal management
I
On-chip thermal shutdown
I
–20 V to –60 V battery operation
I
Programmable current limit
I
Programmable resistive feed
I
Programmable loop-detect threshold
I
Selectable overhead for metering applications
I
Two-wire impedance set by single external
impedance
I
On-chip ring and test relay drivers and relay
snubber circuits
I
Polarity reversal (full transmission)
I
Loop and ground-key detector
I
Comparator for ring-trip detection
I
Ground-start capability
I
On-hook transmission
BLOCK DIAGRAM
TMG
DA
DB
Test Relay
Driver
Ring Relay
Driver
TESTOUT
RINGOUT
A(TIP)
C1
HPA
Two-Wire
Interface
Ring-Trip
Comparator
Ground-Key
Detector
Loop Detector
Input
Decoder
and
Control
C2
C3
C4
E1
HPB
B(RING)
Signal
Transmission
Power-Feed
Controller
Switch Control
DET
RD
VTX
RSN
RDC
CAS
OVH
RFA
VBAT2
VBAT1
BGND
BSWOUT BSWEN BSWTH
VCC
AGND/DGND
Document ID#
080201
Date:
Jun 18, 2002
Rev:
F
Version:
1
Distribution:
Public Document
ORDERING INFORMATION
Standard Products
Legerity standard products are available in several packages and operating ranges. The order number (Valid Combination) is
formed by a combination of the elements below.
Le79489*
–1
J
C
PACKAGE TYPE
TEMPERATURE RANGE
C = Commercial (0° C to 70° C)*
DEVICE NUMBER/DESCRIPTION
Le79489
Subscriber Line Interface Circuit
J = 32-pin Plastic Leaded Chip Carrier (PL 032)
PERFORMANCE GRADE OPTION
–1 = 52 dB Longitudinal Balance, Polarity Reversal
–2 = 60 dB Longitudinal Balance, Polarity Reversal
–3 = 52 dB Longitudinal Balance, No Polarity Reversal
–4 = 60 dB Longitudinal Balance, No Polarity Reversal
–5 = 52 dB Longitudinal Balance, No Polarity Reversal, Metering
–6 = 52 dB Longitudinal Balance, Polarity Reversal, Metering
Valid Combinations
Valid Combinations
–1
–2
–3
–4
–5
–6
Valid Combinations list configurations planned to
be supported in volume for this device. Consult the
local Legerity sales office to confirm availability of
specific valid combinations and to check on newly
released combinations, and to obtain additional
data on Legerity’s standard military–grade
products.
Le79489*
JC
*Legerity reserves the right to fulfill all orders for this device with parts marked with the "Am" part number prefix, until such
time as all inventory bearing this mark has been depleted. It should be noted that parts marked with either the "Am" or the
"Le" part number prefix are equivalent devices in terms of form, fit, and function. The only difference between the two is in
the part number prefix appearing on the topside mark.
2
Le79489 Data Sheet
CONNECTION DIAGRAM
Top View
RINGOUT
B(RING)
VBAT2
BGND
A(TIP)
VCC
4
TESTOUT
BSWOUT
TMG
VBAT1
C4
BSWEN
C1
E1
DET
5
6
7
8
9
10
11
12
13
3
2
1
32 31 30
29
28
27
26
DA
RD
HPB
HPA
NC
VTX
RSVD
RSN
AGND/DGND
32-Pin PLCC
DB
25
24
23
22
21
20
RDC
14 15
C3
C2
16
BSWTH
17 18
OVH
CAS
19
RFA
Notes:
1. Pin 1 is marked for orientation.
2. NC = No Connect
3. RSVD = Reserved. Do not connect to this pin.
Le79489 Data Sheet
3
PIN DESCRIPTIONS
Pin Names
AGND/DGND
A(TIP)
BGND
B(RING)
BSWEN
Type
Gnd
Output
Gnd
Output
—
Analog and Digital ground.
Output of A(TIP) power amplifier.
Battery (power) ground.
Output of B(RING) power amplifier.
Battery Switch Control. Internally connected to automatic battery switch circuitry. BSWEN
can be overridden by external logic. BSWEN Low connects VBAT1 to VBAT2. BSWEN
High disconnects VBAT1 from VBAT2.
Buffered Output. Internally connected to battery switch circuitry. The output is open-
collector with a built-in pull-up resistor. BSWOUT Low indicates VBAT1 is connected to
VBAT2. BSWOUT High indicates VBAT1 is disconnected from VBAT2. This output is
valid only in the Active states.
Input for setting automatic battery switch threshold. Normally tied to Battery 2. Tie to
ground for manual switching.
Decoder. TTL compatible. C3 is MSB and C1 is LSB.
Test Relay Input – Active Low. 1 = Off. 0 = On.
Anti-sat pin for capacitor to filter reference voltage when operating in anti-sat region.
Ring-trip negative. Negative input to ring-trip comparator.
Ring-trip positive. Positive input to ring-trip comparator.
Switchhook detector. When enabled, a logic Low indicates the selected detector is
tripped. The detector is selected by the logic inputs (C3–C1). The output is open-collector
with a built-in 15 kΩ pull-up resistor.
Ground-Key Detect Select. E1 = 1 selects the hook switch detector. E1 = 0 selects the
ground-key detector. In the Tip Open state, ground key is selected independent of E1.
High-Pass Filter Capacitor. A(TIP) side of high-pass filter capacitor.
High-Pass Filter Capacitor. B(RING) side of high-pass filter capacitor.
No connect. This pin not internally connected.
Overhead Control. Logic High enables minimized nonmetering overhead. Logic Low
enables 2.2 V metering DC overhead. TTL-compatible.
Detector resistor. Detector threshold set and filter pin.
DC feed resistor. Connection point for the DC feed current programming network. The
other end of the network connects to the receiver summing node (RSN). Connection point
for the DC feed current programming network. The other end of the network connects to
RSN. V
RDC
is negative for normal polarity and positive for reverse polarity.
Resistive feed adjust. Adjust the DC feed resistance gain coefficient, GDC, with external
resistor connected to ground.
Ring Relay Driver. Open-collector driver with emitter internally connected to BGND.
Receive Summing Node. The metallic current (AC and DC) between A(TIP) and B(RING)
is equal to 500 times the current into this pin. The networks that program receive gain,
two-wire impedance, and feed current all connect to this node.
Reserved. These pins are reserved for Legerity use. Make no connection to these pins.
Test Relay Driver. Open collector driver with emitter internally connected to AGND.
Thermal Management. External resistor connects this pin to VBAT2 to offload power dis-
sipation from SLIC. Functions during normal polarity, Active state.
Most negative battery supply and substrate connection.
Battery supply for output power amplifiers. Switched to VBAT1 by BSWEN.
+5 V power supply.
Transmit Audio. This output is a 0.5066 unity gain version of the A(TIP) and B(RING)
metallic voltage. VTX also sources the two-wire input impedance programming network.
Description
BSWOUT
Output
BSWTH
C3–C1
C4
CAS
DA
DB
DET
Input
Input
Input
Capacitor
Input
Input
Output
E1
HPA
HPB
NC
OVH
RD
RDC
Input
Capacitor
Capacitor
—
Input
Resistor
Resistor
RFA
RINGOUT
RSN
—
Output
Input
RSVD
TESTOUT
TMG
VBAT1
VBAT2
VCC
VTX
—
Output
—
Battery
Battery
Power
Output
4
Le79489 Data Sheet
ABSOLUTE MAXIMUM RATINGS
Storage temperature . . . . . . . . . . . . –55°C to +150°C
With respect to AGND/DGND:
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . .–0.4 V to +7.0 V
V
BAT1
Continuous . . . . . . . . . . . . . . . . . . +0.4 V to –70 V
10 ms . . . . . . . . . . . . . . . . . . . . . . +0.4 V to –75 V
V
BAT2
and BSWTH. . . . . . . . . . . . . . . +0.4 V to V
BAT1
BGND. . . . . . . . . . . . . . . . . . . . . . . . . . . .+3 V to –3 V
A(TIP) or B(RING) with respect to BGND:
Continuous . . . . . . . . . . . . . . . . . . . . V
BAT1
to +1 V
10 ms (f = 0.1 Hz) . . . . . . . . . . . . . . . –70 V to +5 V
1 µs (f = 0.1 Hz) . . . . . . . . . . . . . . . . –80 V to +8 V
250 ns (f = 0.1 Hz) . . . . . . . . . . . . . –90 V to +12 V
Current from A(TIP) or B(RING). . . . . . . . . . ±150 mA
TESTOUT/RINGOUT/current. . . . . . . . . . . . . . 80 mA
TESTOUT/RINGOUT/voltage . . . . . . . BGND to +7 V
TESTOUT/RINGOUT/transient . . . . . BGND to +10 V
DA and DB inputs
Voltage on ring-trip inputs . . . . . . . . . . V
BAT1
to 0 V
Current on ring-trip inputs . . . . . . . . . . . . . ±10 mA
C4–C1, BSWEN, OVH, E1
Input voltage . . . . . . . . . . . . –0.4 V to V
CC
+ 0.4 V
Maximum power dissipation, continuous
T
A
= 70°C, No heat sink (see note):
In 32-pin PLCC package. . . . . . . . . . . . . . . . 1.7 W
Thermal data
. . . . . . . . . . . . . . . . . . . . . . . . . . .θ
JA
In 32-pin PLCC package. . . . . . . . . . . .43°C/W typ
ESD immunity/pin (HBM) . . . . . . . . . . . . . . . . . 1500 V
Note:
Thermal limiting circuitry on chip will shut down the
circuit at a junction temperature of about 165°C. The device
should never be exposed to this temperature. Operation
above 145°C junction temperature may degrade device
reliability. See the SLIC Packaging Considerations section for
more information.
Stresses above those listed under Absolute Maximum Ratings
may cause permanent device failure. Functionality at or above
these limits is not implied. Exposure to Absolute Maximum
Ratings for extended periods may affect device reliability.
OPERATING RANGES
Commercial (C) Devices
Ambient temperature. . . . . . . . . . . . . –40°C to +85°C*
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . 4.75 V to 5.25 V
BAT1 . . . . . . . . . . . . . . . . . . . . . . . . . –40.5 V to –60 V
BAT2 . . . . . . . . . . . . . . . . . . . . . . . . . . .–20 V to BAT1
AGND/DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V
BGND with respect to GND . . . –100 mV to +100 mV
Load resistance on VTX to GND. . . . . . . . . 20 kΩ min
Operating ranges define those limits over which the
functionality of the device is guaranteed by production
testing.
* Legerity guarantees the performance of this device over
commercial (0 to 70°C) and industrial (-40 to 85
°C)
temperature ranges by conducting electrical characterization
over each range and by conducting a production test with
single insertion coupled to periodic sampling. These
characterization and test procedures comply with section
4.6.2 of Bellcore TR-TSY-000357 Component Reliability
Assurance Requirements for Telecommunications
Equipment.
Le79489 Data Sheet
5
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