Le79489
RELAY DRIVER SCHEMATICS
Data Sheet
RINGOUT
TESTOUT
BGND
BGND
Notes:
1. Unless otherwise specified, test conditions are V
CC
= +5 V, BAT1 = –50 V, BAT2 = –34 V, R
L
= 600
Ω,
R
DC1
= R
DC2
= 5.833 kΩ, R
TMG
= 570
Ω,
R
D
= 35.4 kΩ, RFA = 0
Ω,
no fuse resistors, C
HP
= 0.22
µF,
C
DC
= 0.5
µF,
C
CAS
= 0.33
µF,
C
VBAT12
= 220 nF, D
1
= D
2
= 1N400x, OVH
= 1, two-wire AC input impedance is a 600
Ω
resistance synthesized by the programming network shown below.
VTX
R
T1
= 76 kΩ
R
T2
= 76 kΩ
RSN
R
RX
= 150 kΩ
2. a. Overload level exists when THD = 1%.
b. Overload level exists when THD = 1.5%.
C
T1
= 120 pF
V
RX
3. This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization.
4. Not tested in production. This parameter is guaranteed by characterization or correlation to other tests.
5. Tested with 0
Ω
source impedance. 2 MΩ is specified for system design only.
6. Group delay can be greatly reduced by using a Z
T
network such as that shown in Note 1 above. The network reduces the group delay to
less than 2
µs
and increases 2WRL. The effect of group delay on linecard performance also may be compensated for by synthesizing
complex impedance with the DSLAC™ or QSLAC™ device.
7. Minimum current level is guaranteed not to cause a false Loop Detect. The SLIC must be functional in this condition.
8. Four-wire performance is 5–9 dB better than the specified two-wire values.
9. Open loop, Active state, Metering mode power dissipation may be reduced from a typical of 550 mW to a typical of 150 mW by connecting
the DET pin to the OVH pin. This connection will force the SLIC into the nonmetering mode while on hook. With this connection, a me-
tering signal sent after the SLIC goes on hook may be distorted on the 2W line because the SLIC is forced into the nonmetering mode. To
eliminate this distortion, a delay can be added between the time the SLIC goes on hook and the time the SLIC switches to nonmetering
mode by using an RC circuit for the DET pin to OVH pin connection.
9
Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
