LE79R79-1DJC Zarlink, LE79R79-1DJC Datasheet - Page 14

• Manufacturer Part Number: LE79R79-1DJC
• Description: SLIC 1-CH 52dB 110mA 5V 32-Pin PLCC Tube
• Manufacturer: Zarlink

Specifications of LE79R79-1DJC

• Package: 32PLCC
• Number Of Channels Per Chip: 1
• Polarity Reversal: Yes
• Longitudinal Balanced: 52(Min) dB
• Loop Current: 110 mA
• Minimum Operating Supply Voltage: 4.75 V
• Typical Operating Supply Voltage: 5 V
• Typical Supply Current: 6.5 mA

User-Programmable Components
Loop-Threshold Detect Equations
R
Z
Z
R
R
C
R
C
R
R
T
RX
DC1
DC
LTH
LTH
DCR1
DCR
LTH
D
=
=
=
=
500 Z
+
=
=
=
=
+
R
------------ -
G
R
19 ms
-------------- -
12.67
Z
----------------------------- - R
LTH
R
42L
-------------- -
11.37
V
DC2
R
------------------------------------------ - • 150 µs
(
R
L
R
R
DCR2
BAT1
DCR1
D
2WIN
DCR1
D
915
•
•
=
--------------------------------------------------- -
Z
12.67
•
for Active state
T
---------------
I
for high battery state
–
R
---------------------------------- -
2500
LOOP
+
–
10
+
=
R
R
DC1
R
2R
DC1
DCR2
1000 Z
500 Z
---------------------- -
I
DCR2
•
RINGLIM
for high battery state
3000
F
+
R
(
)
D
R
DC2
•
–
L
DC2
400 2R
+
T
2R
–
F
)
F
Zarlink Semiconductor Inc.
Z
R
computing Z
capacitance between VTX and RSN must be taken into account.
Z
desired receive gain.
R
I
R
pin.
See Application Circuit, on page 21.
C
150 µs.
R
loop-resistance threshold between on-hook and off-hook detection. R
should be greater than 56 kΩ to guarantee detection occurs in the
Standby state. Choose the value of R
the equation for R
This is the same equation as for R
For low battery, the detect threshold is slightly higher, which avoids
oscillating between states.
R
guarantees no unstable states under all operating conditions. This
equation shows at what resistance the Standby threshold is; it is
actually a current threshold rather than a resistance threshold, which is
shown by the V
LOOP
T
RX
F
DC1
DCR1
DCR
D
LTH
, and Z
is connected between the VTX and RSN pins. The fuse resistors are
is the resistor connected from the RD pin to GND and R
is connected from V
, R
Standby < R
sets the ringing time constant, which can be between 15 µs and
is the desired loop current in the constant-current region.
14
, R
DC2
2WIN
DCR2
, and C
T
, the internal current amplifier pole and any external stray
, and C
is the desired 2-wire AC input impedance. When
BAT
LTH
LTH
DC
dependency.
DCR
Active V
to find where the threshold is for low battery.
form the network connected to the RDC pin.
RX
form the network connected to the RDCR
to R
BAT1
SN
. Z
D
< R
T
above, except solved for R
for these components.
D
is defined above, and G
LTH
for high battery state; then use
Active V
BAT2
, which
LTH
42L
LTH
is the
is the
.
D