WLL and ISDN-TA subscriber line interface circuit
■ Monochip subscriber line interface circuit
(SLIC) optimised for WLL and VoIP
■ Implement all key features of the BORSHT
■ Single supply (5.5 V to 12 V)
■ Built in DC/DC converter controller
■ Soft battery reversal with programmable
■ On-hook transmission.
■ Programmable off-hook detector threshold
■ Metering pulse generation and filter
■ Integrated ringing
■ Integrated ring trip
■ Parallel control interface (3.3 V logic level)
■ Programmable constant current feed
■ Surface mount package
■ Integrated thermal protection
■ Dual gain value option
■ BCD III S, 90 V technology
■ -40 to +85 °C operating range
The STLC3055N is a SLIC device specifically
designed for wireless local loop (WLL) and ISDN-
terminal adaptors (ISDN-TA) and VoIP
applications. One of the distinctive characteristic
of this device is the ability to operate with a single
supply voltage (from 5.5 V to 12 V) and self
generate the negative battery by means of an
on chip DC/DC converter controller that drives an
external MOS switch.
The battery level is properly adjusted depending
on the operating mode. A useful characteristic for
these applications is the integrated ringing
The control interface is a parallel type with open
drain output and 3.3 V logic levels.
The metering pulses are generated on chip
starting from two logic signals (0 and 3.3 V) one
define the metering pulse frequency and the other
the metering pulse duration. An on chip circuit
then provides the proper shaping and filtering.
Metering pulse amplitude and shaping (rising and
decay time) can be programmed by external
components. A dedicated cancellation circuit
avoid possible codec input saturation due to
metering pulse echo.
Constant current feed can be set from 20 mA to
40 mA. Off-hook detection threshold is
programmable from 5 mA to 9 mA.
The device, developed in BCD III S technology
(90 V process), operates in the extended
temperature range and integrates a thermal
protection that sets the device in power down
when Tj exceeds 140 °C.
Table 1. Device summary
1. ECOPACK® (see Section 10)