Silicon Labs Unveils SLIC Solution for VoIP Gateways

Silicon Labs has launched its Si3226x Dual ProSLIC family of power-efficient subscriber line interface circuit (SLIC) solution for voice-over-IP (VoIP) gateways. The Si3226x family delivers the smallest bill of materials and board area and the lowest power consumption of any dual SLIC available. The devices provides an ideal solution for low channel-count VoIP customer premises equipment (CPE) such as fiber to the home (FTTH) gateways, DSL integrated access devices and cable embedded multimedia terminal adaptors (EMTAs), as well as high-channel count products including multiple-dwelling-unit gateways and PBX systems.

FTTx and other VoIP gateway manufacturers are challenged to fit all the functionality demanded by subscribers into small, inexpensive system designs. The Si3226x SLICs address this challenge by providing two complete channels in a tiny 60-pin 8x8mm QFN package. The tiniest dual foreign exchange station (FXS) solution available, the Si3226x devices enable the lowest BOM cost and smallest footprint per channel for multiline gateways, even smaller than some quad- and octal-channel FXS solutions.

The Si3226x family is the industry’s first FXS solution containing an integrated level shifter/driver that allows a direct connection to a dc-dc converter’s power transistor regardless of input voltage. This innovation eliminates the need for the MOSFET pre-drive circuit required by competing SLIC designs, reducing the cost and footprint of a two-channel design by at least twelve external devices.

The Si3226x family sets a new benchmark in minimizing total FXS system power consumption, requiring less than 55mW per channel when on-hook, making the Dual ProSLIC devices an ideal solution as telecommunication service providers and governments mandate more energy-efficient electronic products. The on-chip intelligent DC/DC converters optimize energy efficiency by generating only the voltages needed in on-hook, off-hook and ringing states. Ultra-low power consumption makes it easier to meet green energy requirements such as the European Commission’s Code of Conduct on Power Consumption for Broadband Equipment; enables longer battery standby time in battery-backed designs; and reduces heat dissipation, eliminating the need for fans in multiline gateway designs, further reducing system cost.

The Si3226x family is designed to generate tracking batteries for lowest power consumption, as well as work with shared battery supplies (e.g., fixed-rail) for the lowest BOM cost. The integrated DC-DC controllers can be configured as either single-output tracking DC-DC converters for each SLIC channel or a single multi-rail DC-DC converter shared by two or more channels. This flexibility allows developers to use the same SLIC device for both low-power tracking designs and low-cost fixed-rail designs. Furthermore, Silicon Labs’ innovative tracking shared supply (TSS) capability significantly reduces the power consumption of two-channel shared-battery designs compared to competitive fixed-rail designs.

Silicon Laboratories