LE79231FQC Zarlink, LE79231FQC Datasheet - Page 16

• Manufacturer Part Number: LE79231FQC
• Description: SLIC 3-CH 63dB 70mA 5V 32-Pin QFN EP
• Manufacturer: Zarlink

Specifications of LE79231FQC

• Package: 32QFN EP
• Number Of Channels Per Chip: 3
• 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: 26.9 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(Continued)
Disconnect
Standby
Tip Open
Active High Battery
Active Low Battery
On-Hook Transmission
(OHT), Fixed Longitudinal
Voltage
C3
1
1
1
1
Operating Mode
C2
0
0
1
1
C1
0
1
0
1
RSVD
Active High Battery
Active Low Battery
RSVD
Operating Mode
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 Le79231 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 “Le79231 ISLIC device Current-Limit Behavior” section. In external ringing, the
standby ISLIC 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 as shown in
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 On-Hook Transmission, Fixed Longitudinal Voltage mode, battery connections are as shown
in
safety specifications for some classes of products.
V SA
----------- -
400
Table
and
1. The longitudinal voltage is fixed at the voltage shown in
V SB
----------- -
400
High Battery
(BATH) and BGND
Low Battery (BATL)
and BGND
Zarlink Semiconductor Inc.
Battery Voltage
, respectively.
Selection
16
Active feed, normal or reverse polarity
Description
Operating Mode
Table 1
Table
to allow compliance with
1. Both output amplifiers
RMGPi & RMGLi
A and B Amplifier
A and B Amplifier
Connection to
Resistors
Output
Output