L7581 Ringing Access Switch
Data Sheet
November 1999
Description
(continued)
To protect the L7581 from an overvoltage fault condi-
tion, use of a secondary protector is required. The sec-
ondary protector must limit the voltage seen at the tip/
ring terminals to prevent the breakdown voltage of the
switches from being exceeded. To minimize stress on
the solid-state contacts, use of a foldback- or crowbar-
type secondary protector is recommended. With proper
choice of secondary protection, a line card using the
L7581 will meet all relevant ITU-T, LSSGR, FCC, or
UL*
protection requirements.
The L7581 operates off of a 5 V supply only. This gives
the device extremely low idle and active power dissipa-
tion and allows use with virtually any range of battery
voltage. This makes the L7581 especially appropriate
for remote power applications such as DAML or FOC/
FITL or other Bellcore TA 909 applications where
power dissipation is particularly critical.
A battery voltage is also used by the L7581, only as a
reference for the integrated protection circuit. The
L7581 will enter an all OFF state upon loss of battery.
During power ringing, to turn on and maintain the ON
state, the ring access switch will draw a nominal 2 mA
or 4 mA from the ring generator.
The L7581 device is packaged in a 16-pin, plastic DIP
package (L7581AC/BC) and a 16-pin, plastic SOG
package (L7581AAE/BAE). These devices are pin
compatible with the L7541 device.
Pin Information
F
GND
NC
T
BAT
T
LINE
T
RINGING
V
DD
NC
T
SD
1
2
3
4
5
6
7
8
SCR
AND
TRIP
CKT
16 V
BAT
15 NC
14 R
BAT
13 R
LINE
12 R
RINGING
11 LATCH
10 INPUT
SW1
SW2
SW3
SW4
TEMPERATURE
SHUTDOWN
9
D
GND
12-2306.a (C)
Note: Shown with A version protection. The 16-pin DIP is available
with either A or B version protection.
Figure 1. 16-Pin, Plastic DIP
F
GND
*
UL
is a registered trademark of Underwriters Laboratories, Inc.
T
BAT
T
LINE
NC
NC
T
RINGING
V
DD
T
SD
1
2
SW1
3
SW3
4
5
6
7
8
TEMPERATURE
SHUTDOWN
SW2
SW4
16 V
BAT
15 R
BAT
14 R
LINE
13 NC
12 R
RINGING
11 LATCH
10 INPUT
9
D
GND
12-2307.a (F)
Note: Shown with B version protection. The 16-pin SOG is available
with either A or B version protection.
Figure 2. 16-Pin, Plastic SOG
2
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
