Austin, Texas - Legerity Inc. has added two 100-volt devices to its line of ringing subscriber line interface circuits (SLICs).
The Am79R100 and Am-79R101 are said to address the need for higher-voltage ringing (70 to 100 V) in Japan and elsewhere, and to meet the five ringer-equivalent requirements for reduced- and short-loop applications.
The SLICs provide on-chip ringing support and battery-switching technology for such communications applications as cable telephony, ISDN terminal adapters, wireless local-loop, fiber-in-the-loop, hybrid fiber/coax and PBX systems.
The Am79R100 and Am-79R101 provide an alternative to ring generators and ring relays in reduced-loop applications. They reduce parts counts and costs by eliminating the need for separate on-board generators and relays.
Battery-switching technology in the SLICs conserves power by switching to a low-battery supply in the off-hook (active) state and then switching to a higher voltage in the on-hook (standby) state. The design is said to decrease power consumption to approximately 40 mW and to reduce costs by eliminating the need for external switches.
The bipolar devices employ a CMOS-compatible input waveform and provide balanced trapezoidal and sine wave ringing.
The Am79R101 differs from the Am79R100 in that it also supports sinusoidal ringing, which suits its waveform for use in small PBX, WLL and Pairgain applications.
The part is said to offer low distortion and to have less crosstalk than one with trapezoidal ringing for large PBX applications in multipair cable transmission. It supports offset ringing and satisfies most telephony applications that require an offset from ring to tip during the ringing, according to Legerity.
The Am79R100 and Am79-R101 are each packaged in a 32-pin PLCC. Prices start at $4.30 per line in 10,000-piece quantities.
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EETInfo No. 611