Obsolete Product(s) - Obsolete Product(s)
DC ELECTRICAL CHARACTERISTICS
(I
L
= 10 mA to 100 mA, R
1
= 56
Ω
, S
1
= Open, T
amb
= + 25
°
C,
unless otherwise specified)
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
L
Line Voltage
(normal mode)
PULSE = Open
IL = 10 mA
I
L
= 20 mA
I
L
= 100 mA
5
6
12
V
V
V
V
LP
Line Voltage
(pulse mode)
PULSE = V
–
I
L
= 20 mA
I
L
= 35 mA
I
L
= 80 mA
4
5.5
9.5
V
V
V
I
hn
ON/OFF-Hook
Line Current Detection
Threshold
6.5 9.5 mA
I
hf
OFF/ON-Hook
Line Current Detection
Threshold
59.2mA
I
OUT
OFF-Hook
Output Drive Current at Pin
HDO
IL = 10 mA
I
L
≥ 20 mA
1.5
1.8
mA
mA
V
PM
Pulse Input Low Voltage 0.8 V
I
PM
Pull-up Input Current at Pin
PULSE (pulse mode)
IL = 100 mA
Pulse = V
–
20 µA
I
NM
Imput Current at Pin Pulse
(normal mode)
3 µA
AC ELECTRICAL CHARACTERISTICS
(I
L
= 10mA to 100mA, R
1
= 56
Ω
, R
2
= 470K
Ω
, R
3
= 130 K
Ω
,
T
amb
= + 25
°
C, unless otherwise specified)
Symbol Parameter Test Condition Min. Typ. Max. Unit
Z
L
AC Line Impedance S
1
= Open, S
2
= Open
C
1
= 2.2mF
f = 1KHz
20 KΩ
Sending/Receiving Distortion S
1
= Open, S
2
= Open
f = 1KHz
V
AC-L
= 775mVrms
I
L
= 15 to 100mA
2%
Sending/Receiving Distortion S
1
= Closed; S
2
= Open
V
AC-L
= 1.3Vrms 2 %
Sending/Receiving Distortion S
1
= Open; S
2
= Closed
V
AC-L
= 1.9Vrms
2(*) %
(*) Not tested, guaranteed only by design.
APPLICATION INFORMATION
With the use of this circuit it is possible to termi-
nate an analog trunk so that all the DC current
component is flowing in the TRUNK TERMINA-
TION CIRCUIT while the AC component is de-
coupled with a low voltage capacitor and can be
used with a small and low cost audio coupler
transformer to provide the AC balancing termina-
tion and two to four wire conversion.
Therefore it is usefull both for MODEM and PABX
systems.
Figure 1 gives the typical application circuit ; it is
worth to note that the TRUNK TERMINATION
CIRCUIT, together with the LS5018 transient sup-
pressor provides a compact and low cost module
fully protected against lightning or overvoltages
frequently present on telephone lines.
The
PULSE input when connected to V- allows
the device to reduce the Line Voltage and to
show a resistive impedance equal to R1 to the
line. When
PULSE input is left open, this function
is disable.
L3845
3/8