L9214A/G
Low-Cost Ringing SLIC
Preliminary Data Sheet
October 2001
The default overhead provides sufficient headroom for
on-hook transmission of a +3.17 dBm signal into
600 Ω.
+3.17 dBm = 10 log (Vrms2 / P0 * R600 Ω)
Applications (continued)
dc Loop Current Limit
In the active modes, dc current limit is programmable
via an external resistor. The resistor is connected
between IPROG and DCOUT. The loop current limit
(ILOOP) with 100 Ω load is related to the RIPROG pro-
gramming resistor by:
dBm = 10 log (Vrms2 / 0.001 W * 600 Ω)
Vrms2
-------------------------------
+3.17 dBm = 10 log
0.6(IV × R)
Vrms = 1.12 V and Vpeak = 1.58 V are supported.
ILOOP (mA) = 4 mA/kΩ * RIPROG (kΩ) + 2 mA
Note that the overall current-limit accuracy achieved
will be affected by the specified accuracy of the internal
SLIC current-limit circuit and the accuracy of the exter-
nal resistor.
Scan Mode
If the magnitude of the primary battery is greater than
a nominal –63 V, the magnitude of the open-loop tip
to ring voltage is clamped to between –42.5 V and
–56.5 V.
The above equation describes the active mode steady-
state current-limit response. There will be a transient
response of the current-limit circuit upon an on- to off-
hook transition. Typical active mode transient current-
limit response is given in Table 18.
Again, the overhead is not symmetrical with respect to
tip and ring. With the magnitude of the primary battery
greater than a nominal –63 V, the tip to ground voltage
is clamped between –0.1 V and –0.6 V and the ring to
ground voltage is clamped between –42.5 V and
–56.5 V. If the magnitude of the primary battery is less
than a nominal –63 V, the tip to ground voltage is
–0.1 V to –0.6 V and the ring to battery voltage is typi-
cally 17 V less than VBAT1.
Table 18. Typical Active Mode On- to Off-Hook Tip/
Ring Current-Limit Transient Response
Parameter
Value
Unit
dc Loop Current: Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 20 ms
ILOOP + 60 mA
On-Hook Transmission Mode
dc Loop Current: Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 30 ms
ILOOP + 20 mA
If the magnitude of the primary battery is greater than
63 V, the magnitude of the open-loop tip to ring voltage
will be greater than 42.5 V. If the magnitude of the pri-
mary battery is less than 63 V, the open-loop voltage
may be less than 42.5 V and is approximately 17 V less
than the magnitude of the primary battery voltage. For
primary battery voltages less than 70 V, the magnitude
of the ring to ground voltage will be less than 56.5 V.
dc Loop Current: Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 50 ms
ILOOP
mA
Overhead Voltage
Active Mode
Again, the overhead is not symmetrical with respect to
tip and ring. The tip voltage to ground is between –2 V
and –4.5 V and the ring to primary voltage is 14.5 V
typical.
The overhead is preprogrammed in the active mode.
Note that overhead is not symmetrical with respect to
tip and ring. Under default conditions, the tip to ground
voltage is 2.1 V to 2.6 V and the ring to battery over-
head is 14.5 V typical.
Agere Systems Inc.
25
AGERE [ AGERE SYSTEMS ]
