le79r70 Zarlink Semiconductor, le79r70 Datasheet - Page 11

• Manufacturer Part Number: le79r70
• Description: Ringing Subscriber Line Interface Circuit
• Manufacturer: Zarlink Semiconductor

Notes:
1. Unless otherwise noted, test conditions are BAT1 = –67 V, BAT2 = –24 V, V
2. a. Overload level is defined when THD = 1%.
3. Balance return signal is the signal generated at V
4. Not tested in production. This parameter is guaranteed by characterization or correlation to other tests.
5. This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization.
6. Group delay can be greatly reduced by using a Z
7. Open Circuit V
8. R
9. Lower power is achieved by switching into low-battery state in standby. Standby loop current is returned to V
Notes:
* Only –1 performance grade devices support polarity reversal.
** For correct ground-start operation using Tip Open, V
R
two-wire AC input impedance (ZSL) is a 600 Ω resistance synthesized by the programming network shown below.
R
b. Overload level is defined when THD = 1.5%.
matches the programmed impedance.
group delay to less than 2 µs and increases 2WRL. The effect of group delay on line card performance may also be compen-
sated for by synthesizing complex impedance with the QSLAC or DSLAC device.
of the battery selected.
State
DC1
SGL
D
6*
7*
0
1
2
3
4
5
must be greater than 56 kΩ. Refer to
= 80 kΩ, R
= open, R
C3 C2 C1
AB
0
0
0
0
1
1
1
1
SGH
DC2
can be modified using RSGH.
0
0
1
1
0
0
1
1
= 20 kΩ, R
= open, R
0
1
0
1
0
1
0
1
DCR
D
Open Circuit
Ringing
Active
On-hook TX (OHT)
Tip Open
Standby
Active Polarity Reversal
OHT Polarity Reversal
= 75 kΩ, no fuse resistors, C
VTX
RSN
= 2 kΩ, R
RT1 = 150 kΩ
RT2 = 150 kΩ
2-Wire Status
Table 2
RT1
Table 1. SLIC Decoding
Zarlink Semiconductor Inc.
= 430 kΩ, R
TX
for typical value of R
T
network such as that shown in Note 1 above. The network reduces the
by V
BAT1
RX
RRX = 300 kΩ
on-hook battery must be used.
. This specification assumes that the two-wire AC load impedance
11
Ring trip
Ring trip
Loop detector
Loop detector
Loop detector
Loop detector
Loop detector
Loop detector
RT2
HP
= 0.018 µF, C
= 12 kΩ, C
E1 = 1
CT1 = 60 pF
LTH
(DET) Output
.
~
RT
V
CC
RX
DC
= 1.5 µF, R
= +5 V, V
Ring trip
Ring trip
Ground key
Ground key
Ground key
Ground key
Ground key
Ground key
= 1.2 µF, D
E1 = 0
NEG
SLEW
1
= –5 V, R
= D
= 150 kΩ, C
2
= 1N400x,
Battery Selection
L
= 600 Ω,
B2EN = 1**
SLEW
BAT1
B2EN
V
B2EN
BAT1
regardless
= 0.33 µF.