le9531cmqc Zarlink Semiconductor, le9531cmqc Datasheet - Page 27

• Manufacturer Part Number: le9531cmqc
• Description: Ringing Subscriber Line Interface Circuit
• Manufacturer: Zarlink Semiconductor

Sine Wave Input Signal and Sine Wave Power Ring Signal Output
The low-voltage sine wave input is applied differentially or single ended to the Le9531 device at pins RINGP/N.
During the ring state, the signals at pins RINGP/N are amplified and presented to the subscriber loop. The
differential gain from RINGP/N to tip and ring in the Ringing mode, which is different when the device is in Active
state, is specified in the device specifications.
When the device enters the Ring state, the clamp circuit is disabled, allowing the voltage magnitude of the power
ring signal to be maximized. Additionally, in the Ring state, the loop current limit is increased and is not limited by
DC loop current limit.
The magnitude of the power ring voltage will be a function of the gain of the ring amplifier, the high-voltage battery,
and the input signal at RINGP/N. The input range of the signal at RINGP/N is 0 V to Vcc. As the input voltage at
RINGP/N is increased, the magnitude of the power ring voltage at tip and ring will increase linearly, until the tip and
ring drive amplifiers begin to saturate. Once the tip and ring amplifiers reach saturation, further increases of the
input signal will cause clipping distortion of the power ring signal at tip and ring. The ring signal will appear balanced
on tip and ring. That is, the power ring signal is applied to both tip and ring, with the signal on tip 180 degree out of
phase from the signal on ring.
The point at which clipping of the power ring signal begins at tip and ring is a function of the battery voltage and the
input signal at RINGP/N.
Power Ringing with Le9531D
For operation of the Le9531D device with a high magnitude on V
given to the following areas at the system level. V
power ringing. The amplitude of V
The amplitude of V
operation.
Design Examples
The following reference circuit shows the complete SLIC device schematic for interface to the new Broadcom ICs
such as BCM3378/3380/3382/6816. This circuit has a natural 700- AC termination impedance. The Broadcom IC
has programmable registers to modify the external 700- termination to any other real or complex terminations, as
well as to set transmit and receive gains, and other AC parameters. The Broadcom IC also drives ringing inputs,
sets SLIC operation states, and monitors NSTAT. The voltage of the battery supply to the SLIC V
be properly set and may vary depending upon SLIC operational states. The ringing maybe driven by the same
voice outputs or by the separate PWM outputs.
Figure 8 shows the ringing is driven by PWM output path.
Figure 9 shows the ringing is driven by the same voice path.
Contact your Zarlink account representative for assistance with other applications.
BAT
may not exceed 100 V during the silent period of ringing or any other non-ringing mode of
BAT
should not exceed 100 V when the SLIC device is not in the Ringing mode.
Zarlink Semiconductor Inc.
Le9531
BAT
may be more negative than -100 V only during the actual
27
BAT
greater than 100 V, special attention must be
BAT
Data Sheet
is expected to