stlc30r81 STMicroelectronics, stlc30r81 Datasheet - Page 5

• Manufacturer Part Number: stlc30r81
• Description: Integrated Ringing Slic For Short Loop Applications
• Manufacturer: STMicroelectronics

STLC30R81
GDK/AL detectors are active. DC line loop current is limited at 15mA (not programmable). DC characteristic is
shown in Fig.1. The line feeding voltage in On-Hook is typically 42V @ VBAT2 = -74V.
Figure 1. Characteristic in StBy Mode
I
15mA
R
= 2R
FEED
P
V
42V
D03TL590
Active - NP (normal polarity) or RP (reverse polarity)
Mode selected to allow voice signal transmission. When in ACTIVE mode V
is selected automatically and
BAT1
the voltage drop in on-hook condition is 7.8V. Concerning AC characteristic the STLC30R81 allows to set 2Wire
termination impedance by means of external scaled impedance.
In ACTIVE mode the SLIC can perform battery reversal in a soft way, with programmable transition time, without
affecting the AC signal transmission. It is possible to program, by means of an external resistor RLIM, the value
of the current limitation in a range of 20 to 45mA. During On/Off-Hook transition, the SLIC line drivers limit the
transient current at Ilim +13mA.
Figure 2. DC Characteristic in Active mode
IL
20mA ~ 45mA
R
= 2R
FEED
P
VL
V
-7.8V
D03TL591
BAT1
Active - ON-Hook transmission
This mode is selected to allow caller ID transmission in On-Hook line condition. The line feeding voltage in On-
Hook transmission is 42V @ V
= -74V.
BAT2
High Impedance feeding
As in Stand-By, this mode is set in On-Hook condition, with further reduced power consumption. Higher power
efficiency turns back to a lower immunity of the Off-Hook detector to line common mode currents. The DC feed-
ing shows a constant current characteristic (Ilim = 18mA) followed by a resistive range with an equivalent series
resistance Rfeed = 1600 + 2Rp (Fig.3). The line feeding voltage in On-Hook is 50V @ V
= -74
BAT2
Thermal protection circuit is still active, preventing the junction temperature, in case of fault condition, to exceed
150°C. In High Impedance Feeding most of the circuit is switched off, only the circuit, dedicated to Off-Hook
detection, is powered. This allows reducing the total power consumption in On-hook to 30mW (typical).
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