Preliminary Data Sheet
September 2001
L9216B/H
High-Voltage Ringing SLIC with Ground Start
Supervision
(continued)
0
VRING
VTIP
Power Ring
(continued)
–20
Sine Wave Input Signal and Sine Wave Power Ring
Signal Output
–40
The low-voltage sine wave input is applied to the L9216
at pin RING
IN
. This signal should be ac-coupled
through 0.47
µF.
During the ring mode, the signal at
RING
IN
is amplified and presented to the subscriber
loop. The differential gain from RING
IN
to tip and ring is
a nominal 55.
When the device enters the ring mode, the tip/ring
overhead set at OVH and the scan clamp circuit is dis-
abled, allowing the voltage magnitude of the power ring
signal to be maximized. Additionally, in the ring mode,
the loop current limit is increased 2.5X the value set by
the V
PROG
voltage.
The magnitude of the power ring voltage will be a func-
tion of the gain of the ring amplifier, the high-voltage
battery, and the input signal at RING
IN
. The input range
of the signal at RING
IN
is 0 V to Vcc. As the input volt-
age at RING
IN
is increased, the magnitude of the power
ring voltage at tip and ring will increase linearly, per the
differential gain of 55, until the tip and ring drive amplifi-
ers 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°
(180 degrees) out of phase from the signal on ring.
prior to saturation of the tip and ring drive amplifiers. A
–70 V battery is used with a 100
Ω
loop and a 1 REN
load. The input signal is 1 V through a 0.47
µF
capaci-
tor at RING
IN
, (the input circuit is shown in Figure 11).
This produces a voltage swing from –34 V to –60 V
on ring and from –8 V to –34 V on tip, as shown in
8 V) for a 1 V input, which is approximately the differen-
tial gain of the device. Note that the tip and ring power
ring signals will swing around V
BATTERY
divided by two.
In this case, there is a –70 V battery so tip and ring
swing around –34 V.
–60
0.60 0.62
0.64
0.66
0.68
0.70
TIME
12-3573F
1.0
VRINGIN
0.72
0.74
0.76
0.78 0.80
0.5
0.0
–0.5
–1.0
0.60 0.62
0.64
0.66
0.68
0.70
TIME
12-3574F
0.72
0.74
0.76
0.78
0.80
Figure 10. Ring Mode Typical Operation
Agere Systems Inc.
25
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
