LUCL9311AP-D AGERE [Agere Systems], LUCL9311AP-D Datasheet - Page 38

• Manufacturer Part Number: LUCL9311AP-D
• Description: Line Interface and Line Access Circuit Full-Feature SLIC with High Longitudinal Balance, Ringing Relay,and GR-909 Test Access
• Manufacturer: AGERE [Agere Systems]

Ringing Relay, and GR-909 Test Access
Special Functions
Line Test
The L9311 provides line test capability. Through a
series of integrated analog switches, in the test mode,
an analog voltage proportional to the dc tip to ground
voltage, dc ring to ground voltage, the differential dc tip
to ring voltage may be generated at the SLIC
TESTLEV output. Additionally an analog voltage pro-
portional to the dc tip to ground current, dc ring to
ground current, the differential dc tip to ring current
may also be generated at the SLIC TESTLEV.
Figure 2 shows the architecture of the integrated test
switches. The test switches are configured via the logic
input table to provide voltage measurements, tip to
ground, ring to ground and tip to ring. A voltage that is
proportional to the ac tip/ring current appears at the
VITR output; thus, for ac current measurements, the
test switches apply the VITR output to the TESTLEV
output. A voltage that is proportional to the ac plus dc
tip/ring current appears at the VTX output; thus, for dc
current measurements, the test switches apply the VTX
output to the TESTLEV output, with TESTSIG input
grounded.
Differential tip to ring current is achieved via the logic
truth table. Additionally, individual control of the line
break switches allows tip to ground current measure-
ments (tip break switch closed, ring break switch open,
tip amp state) or ring to ground current measurements
(tip break switch open, ring break switch closed, ring
amp state).
An analog ac test tone may also be applied to a test
input TESTSIG. TESTSIG input is active upon entering
a test state and remains active until leaving the test
38
mode. Using this feature, a voltage proportional to ac
tip to ground voltage, ac ring to ground voltage, the dif-
ferential ac tip to ring, the ac tip to ground current, ac
ring to ground current, the differential ac tip to ring cur-
rent may also be generated at the SLIC TESTLEV. By
varying the frequency of the applied test tone, parame-
ters such as line capacitance may be measured.
If the codec can accommodate self-test features, the
L9311 can be configured to operate in this mode. Dur-
ing the test modes. The L9311 receive path is active,
thus a test tone may be applied at the RCVN/RCVP
inputs, through the codec, via a PCM input. In this
mode of operation, couple TESTLEV, not VITR, to the
codec.
All measurements that appear at the TESTLEV output
are referenced to the internal V
device. For that reason, there is a test mode in which
V
When making a voltage measurement, first measure
V
When making a current measurement, open the line
break switches and measure V
then subtracted from the V
the actual measurement. Note that due to internal bias-
ing of the line break switches, the value seen at
V
than the value seen with the line break switches closed
under on-hook (open-loop) conditions.
TESTSIG should be externally connected to the
device’s V
This may be done by a high-impedance pull-up resis-
tor. Additionally TESTSIG should be ac-coupled to the
test signal generator.
REF
REF
TESTLEV
itself will appear at the TESTLEV output.
and subtract V
with the line break switches open will be less
REF
if it is not used during a test condition.
REF
from V
TESTLEV
TESTLEV
TESTLEV
REF
that is seen during
voltage of the
Agere Systems Inc.
.
. This value is
July 2001