Ringing SLIC Module

Specifications

QCX601

+3.3V ~ +5.0V Low Power Ringing SLIC

    The QCX601 is designed for use short loop “on-premise” applications, such as FCT, FWT, WLL and VoIP. In this case power cross and lightning protection is not required. The only protection which should be required is for ESD (Electro Static Discharge) caused by handling during installation.

Features

    Single supply voltage: +3.3V to +5.0V.

    Integral high efficiency DC/DC converter.

    Transformerless 2-wire to 4-wire conversion

    Integral ringing generator

    Constant current feed

    Tip/Ring Polarity reversal

    On-hook transmission

    Off-hook detection

    Easy to use, with a minimum number of external components.

    Simplified protection in “on-premise” applications.

  Applications

    Voice Over Internet Protocol (VoIP)

    Cable Modems

    Key Telephone System

    IP Gateway system

    Wireless Desktop Phone

    Set-top Box System

    Voice Over DSL (VoDSL)

   Short Loop Access Platforms

   Remote Subscriber Units

   Other Terminal Adapters

Functional Description

1.Switch Hook Detection

When the subscriber goes “off-hook” loop current will begin to flow. If this current is above the detection threshold the switch hook output, SHK, will switch to a logic (H). It is recommended that software or hardware de-bouncing of the switch hook signal is used. This is to avoid short pulses which can cause a false switch hook output, triggering the incorrect system response.

During loop disconnect dialling, SHK will pulse between logic (H) and logic (L) to indicate the digits being dialled. Again it is recommended that software de-bouncing of the pulse edges is used to avoid false detection of digits

2.Tip & Ring Polarity

The QCX601 can reverse the battery voltage polarity at Tip and Ring via the RFL pin. RC and 25HZ is at logic (L):

If RFL is held at logic (H) (Forward) the d.c. voltage at Ring is negative with respect to Tip. If RFL is taken to logic (L) (Reverse) the voltage at Ring is positive with respect to Tip.