LUCL9310AP-D AGERE [Agere Systems], LUCL9310AP-D Datasheet - Page 35

• Manufacturer Part Number: LUCL9310AP-D
• Description: Line Interface and Line Access Circuit Full-Feature SLIC,Ringing Relay,and Test Access Device
• Manufacturer: AGERE [Agere Systems]

July 2001
Applications
dc Characteristics
dc Loop Current Limit (continued)
Note that the overall current-limit accuracy achieved
will not only be affected by the specified accuracy of
the internal SLIC current-limit circuit (accuracy associ-
ated with the 50 term), but also by the accuracy of the
voltage source and the accuracy of any external resis-
tor divider network used and voltage offsets due to the
specified input bias current. If a resistor divider from
V
more accurate result due to a lower offset associated
with the input bias current; however, lower value resis-
tors will also draw more power from V
the two resistors in the resistor divider should be
between 75 k
accuracies are specified in Table 9 and Table 10.
The above equation describes the active mode steady-
state current-limit response. There will be a transient
response of the current-limit circuit (with the device in
the active mode) upon an on- to off-hook transition.
Typical active mode transient current-limit response is
given in Table 18.
Table 18. Typical Active Mode On- to Off-Hook Tip/
The current limit with the SLIC set in an active mode
will be different from the current limit with the SLIC set
in the scan mode. This is due to differences in the scan
clamp circuit versus the active tip/ring drive amplifiers.
The scan mode current limit is fixed and is a function of
the internal design of the scan clamp circuit. The
steady-state scan mode current limit will be a typical
40 mA to 50 mA and may, over temperature and pro-
cess, vary typically from 30 mA to 110 mA. The scan
clamp current limit will typically settle to its steady-state
value within 300 ms.
Agere Systems Inc.
dc Loop Current:
dc Loop Current:
dc Loop Current:
REF
Active Mode
R
Active Mode
R
Active Mode
R
LOOP
Transition t < 5 ms
LOOP
Transition t < 50 ms
LOOP
Transition t < 300 ms
is used, a lower magnitude resistor will give a
= 100
= 100
= 100
Ring Current-Limit Transient Response
Parameter
and 200 k . Offset at V
On- to Off-hook
On- to Off-hook
On- to Off-hook
(continued)
(continued)
REF
I
I
LIM
LIM
PROG
Value
Full-Feature SLIC, Ringing Relay, and Test Access Device
. The sum of
I
LIM
+ 60
+ 20
and V
Unit
mA
mA
mA
REF
Overhead Voltage
Overhead is programmable in the active mode via an
applied voltage source at the device’s OVH control
input. The voltage source may be an external voltage
source or derived via a resistor divider network from
the V
programmable external voltage source may be used to
provide software control of the overhead voltage.
The overhead voltage (V
age by:
V
Overall accuracy is determined by the accuracy of the
voltage source and the accuracy of any external resis-
tor divider network used and voltage offsets due to the
specified input bias current. If a resistor divider from
V
accurate result due to a lower offset associated with
the input bias current; however, lower value resistors
will also draw more power from V
gramming resistors should be between 75 k and
200 k .
Note that a default overhead voltage of 5.5 V is
achieved by shorting input pin OVH to analog ground.
Internally, the SLIC needs typically 2 V from each sup-
ply rail to bias the amplifier circuitry. This can be
thought of as an internal saturation voltage.
The default overhead provides sufficient headroom for
on-hook transmission of a 3.14 dBm signal into 900
3.14 = 10 log
V = 1.36 V, which is required over and above the inter-
nal saturation voltage for signal swing.
1.36 V + 4 V = 5.36 V < 5.5 V default overhead; thus, a
3.14 dBm into 900
distortion.
The overhead voltage accuracy achieved will not only
be affected by the accuracy of the internal SLIC cir-
cuitry, but also by the accuracy of the voltage source
and the accuracy of any external resistor divider net-
work used.
In the scan mode, overhead is unaffected by V
internally fixed by the scan clamp circuitry to within the
specified limits.
OH
REF
= 5.5 V + 5 x V
REF
is used, lower magnitude resistor will give a more
SLIC output or an external voltage source. A
-------- -
0.9
V
2
OVH
signal is passed without clipping
(V)
OH
) is related to the OVH volt-
REF
. The sum of pro-
OVH
and
35
.