LUCL9215AAU-D AGERE [Agere Systems], LUCL9215AAU-D Datasheet - Page 27

• Manufacturer Part Number: LUCL9215AAU-D
• Description: Short-Loop Sine Wave Ringing SLIC
• Manufacturer: AGERE [Agere Systems]

September 2001
Supervision
The L9215 offers the loop closure and ring trip supervi-
sion functions. Internal to the device, the outputs of
these detectors are multiplexed into a single package
output, NSTAT. Additionally, a common-mode current
detector for tip or ring ground detection is included for
ground key applications.
Loop Closure
The loop closure has a fixed typical 10.5 mA on- to off-
hook threshold in the active mode and a fixed 11.5 mA
on- to off-hook threshold from the scan mode. In either
case, there is a 2 mA hysteresis with V
1 mA hysteresis with V
Ring Trip
The ring trip detector requires only a single-pole filter at
the input, minimizing external components. An R/C
combination of 383 k and 0.1 F, for a filter pole at
5.15 Hz, is recommended.
The ring trip threshold is internally fixed as a function of
battery voltage and is given by:
RT (mA) = 67 * {(0.0045 * V
where:
RT is ring trip current in mA.
V
There is a 6 mA to 8 mA hysteresis.
Tip or Ring Ground Detector
In the ground key or ground start applications, a com-
mon-mode current detector is used to indicate either a
tip- or ring-ground has occurred (ground key) or an off-
hook has occurred (ground start). The detection thresh-
old is set by connecting a resistor from ICM to V
170 x V
Additionally, a filter capacitor across R
time constant of the detector. No hysteresis is associ-
ated with this detector.
Power Ring
The device offers a ring mode, in which a balanced
power ring signal is provided to the tip/ring pair. During
the ring mode, a user-supplied low-voltage ring signal
Agere Systems Inc.
BAT1
is the magnitude of the ring battery in V.
CC
/R
ICM
(k ) = I
CC
TH
= 3.3 V.
(mA)
BAT1
) + 0.317}
ICM
CC
= 5 V and a
will set the
CC
.
is input to the device’s RING
amplified to produce the balanced power ring signal.
The user may supply a sine wave input, PWM input, or
a square wave to produce sinusoidal or trapezoidal
ringing at tip and ring.
Various crest factors are shown below for illustrative
purposes.
Note: Slew rate = 5.65 V/ms; trise = tfall = 23 ms; pwidth = 2 ms;
Note: Slew rate = 10.83 V/ms; trise = tfall = 12 ms; pwidth = 13 ms;
Voltage applied to the load may be increased by using
a filtered square wave input to produce a lower crest
factor trapezoidal power ring signal at tip and ring.
Figure 10. Ringing Waveform Crest Factor = 1.2
Figure 9. Ringing Waveform Crest Factor = 1.6
period = 50 ms.
period = 50 ms.
Short-Loop Sine Wave Ringing SLIC
–20
–40
–60
–80
–20
–40
–60
–80
80
60
40
20
80
60
40
20
0.00
0.00
0
0
0.02 0.06
0.02 0.06
0.04 0.08
0.04 0.08
TIME (s)
TIME (s)
0.10
0.10
IN
0.12
0.12
input. This signal is
0.14
0.14
0.16
0.16
0.18
0.18
0.20
0.20
12-3346a (F)
12-3347a (F)
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