L9216B/H
Preliminary Data Sheet
September 2001
High-Voltage Ringing SLIC with Ground Start
Overhead Voltage
Active Mode
Applications (continued)
dc Loop Current Limit
Overhead is fixed to a nominal 6.0 V, which is adequate
for on-hook transmission of 3.14 dBm into 900 Ω.
Current limit may be chosen from two discrete values,
25 mA or 40 mA, depending on if VPROG is grounded
(25 mA) or left floating (40 mA). Note that there is a
12.5 kΩ slope to the I/V characteristic in the current-
limit region; thus, once in current limit, the actual loop
current will increase slightly, as loop length decreases.
Scan Mode
If the magnitude of the primary battery is greater than
51 V, the magnitude of the open loop tip-to-ring open
loop voltage is clamped typically between 44 V and
51 V. If the magnitude of the primary battery is less
than a nominal 51 V, the overhead voltage will track the
magnitude of the battery voltage, i.e., the magnitude of
the open circuit tip-to-ring voltage will be 4 V to 6 V less
than battery. In the scan mode, overhead is unaffected
by VOVH.
The above paragraph 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 19.
Table 19. Typical Active Mode On- to Off-Hook Tip/
Ring Current-Limit Transient Response
On-Hook Transmission Mode
Parameter
dc Loop Current:
Value
Unit
ILIM + 60
mA
If the magnitude of the primary battery is greater than
51 V, the magnitude of the open loop tip-to-ring open
loop voltage is clamped typically between 41 V and
49 V. If the magnitude of the primary battery is less
than a nominal 51 V, the overhead voltage will track the
magnitude of the battery voltage, i.e., the magnitude of
the open circuit tip-to-ring voltage will be 6 V to 8 V less
than battery. In the scan mode, overhead is unaffected
by VOVH.
Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 5 ms
dc Loop Current:
Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 50 ms
ILIM + 20
mA
mA
dc Loop Current:
ILIM
Active Mode
RLOOP = 100 Ω On- to Off-hook
Transition t < 300 ms
22
Agere Systems Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
