L9216B/H
High-Voltage Ringing SLIC with Ground Start
Preliminary Data Sheet
September 2001
Overhead Voltage
Active Mode
Overhead is fixed to a nominal 6.0 V, which is adequate
for on-hook transmission of 3.14 dBm into 900
Ω.
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 V
OVH
.
On-Hook Transmission 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 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 V
OVH
.
Applications
(continued)
dc Loop Current Limit
Current limit may be chosen from two discrete values,
25 mA or 40 mA, depending on if V
PROG
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.
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
Parameter
dc Loop Current:
Active Mode
R
LOOP
= 100
Ω
On- to Off-hook
Transition t < 5 ms
dc Loop Current:
Active Mode
R
LOOP
= 100
Ω
On- to Off-hook
Transition t < 50 ms
dc Loop Current:
Active Mode
R
LOOP
= 100
Ω
On- to Off-hook
Transition t < 300 ms
Value
I
LIM
+ 60
Unit
mA
I
LIM
+ 20
mA
I
LIM
mA
22
Agere Systems Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
