LE79R241DJC Zarlink, LE79R241DJC Datasheet - Page 16

• Manufacturer Part Number: LE79R241DJC
• Description: SLIC 1-CH 63dB 70mA 5V 32-Pin PLCC Tube
• Manufacturer: Zarlink

Specifications of LE79R241DJC

• Package: 32PLCC
• Number Of Channels Per Chip: 1
• Polarity Reversal: Yes
• Longitudinal Balanced: 63 dB
• Loop Current: 70(Min) mA
• Minimum Operating Supply Voltage: 4.75 V
• Typical Operating Supply Voltage: 5 V
• Typical Supply Current: 7.5 mA

Note:
1.
Operating Mode Descriptions
In these modes, the ring lead (B-lead) output has a –50 V internal clamp to battery ground (BGND).
Table 1. Operating Modes
Disconnect
Standby
Tip Open
Active High
Battery
Active Low
Battery
Active Internal
Ringing
On-Hook
Transmission
(OHT), Fixed
Longitudinal
Voltage
Operating Mode
C3
0
0
0
0
1
1
1
1
C2
0
0
1
1
0
0
1
1
C1
0
1
0
1
0
1
0
1
This mode disconnects both A and B output amplifiers from the AD and BD outputs. The A and B amplifiers are
shut down and the Le79R241 ISLIC device selects the low battery voltage at the VBL pin. In the Disconnect
state, the currents on IMT and ILG represent the voltages on the SA and SB pins, respectively. These currents
are scaled to produce voltages across RMTi and RLGi of
The power amplifiers are turned off. The AD output is driven by an internal 250 Ω (typical) resistor, which
connects to ground. The BD output is driven by an internal 250 Ω (typical) resistor, which connects to the high
battery (BATH) at the VBH pin, through a clamp circuit, which clamps to approximately –50 V with respect to
BGND. For VBH values above –55 V, the open-circuit voltage, which appears at this output is ~VBH + 7 V. If
VBH is below –55 V, the voltage at this output is –50 V. The battery selection for the balance of the circuitry on
the chip is VBL. Line supervision remains active. Current limiting is provided on each line to limit power
dissipation under short-loop conditions as specified in
the Standby Le79R241 ISLIC device state is selected.
In this mode, the AD (Tip) lead is opened and the BD (Ring) lead is connected to a clamp, which operates from
the high battery on VBH pin and clamps to approximately –50 V with respect to BGND through a resistor of
approximately 250 Ω (typical). The battery selection for the balance of the circuitry on the chip is VBL.
In the Active High Battery mode, battery connections are connected as shown in Table 1. Both output amplifiers
deliver the full power level determined by the programmed DC-feed conditions. Active High Battery mode is
enabled during a call in applications when a long loop can be encountered.
Both output amplifiers deliver the full power level determined by the programmed DC-feed conditions. VBL, the
low negative battery, is selected in the Active Low Battery mode. This is typically used during the voice part of
a call.
In the Internal Ringing mode, the Le79R241 ISLIC device selects the battery connections as shown in Table 1.
When using internal ringing, both the AD and BD output amplifiers deliver the ringing signal determined by the
programmed ringing level.
In the On-Hook Transmission, Fixed Longitudinal Voltage mode, battery connections are as shown in
The longitudinal voltage is fixed at the voltage shown in
for some classes of products.
Standby (See note 1)
Tip Open (See note 1)
On-Hook
Transmission, Fixed
Longitudinal Voltage
Disconnect
RSVD
Active High Battery
Active Low Battery
Active Internal Ringing
Operating Mode
Zarlink Semiconductor Inc.
High Battery (BATH)
and BGND
High Battery (BATH)
and BGND
High Battery (BATH)
and BGND
Low Battery
selection at VBL
High Battery (BATH)
and BGND
Low Battery (BATL)
and BGND
High Battery (BATH)
and BGND
Battery Voltage
Selection
16
Description
(High ohmic feed): Loop supervision
active, A and B amplifiers shut down
Tip Open: AD at High-Impedance,
Channel A power amplifier shut down
Fixed longitudinal voltage of –28 V
AD and BD at High-Impedance,
Channel A and B power amplifiers
shut down
Active feed, normal or reverse polarity
Active internal ringing
Current-Limit Behavior, on page
Table 1
V
----------
400
SA
Operating Mode
and
to allow compliance with safety specifications
V
----------
400
SB
, respectively.
15. In external ringing,
Open
Open
A and B Amplifier
Output
RMGPi & RMGLi
Connection to
Resistors
Table
1.