ICs provide advanced voice features, low power consumption

Silicon Laboratories Inc. has rolled out its next-generation data modem ICs that the company said provide advanced voice features, lower power consumption, reduced BOM costs and flexible interface options for many applications. The Si24xx ISOmodem family focuses on voice and machine-to-machine (M2M) communications for home automation systems, smart utility meters, set-top boxes and many other electronics systems that connect to the public switched telephone network (PSTN).

The chipset's voice feature set is more comprehensive and offers better performance and audio fidelity than legacy data modem solutions, the company stated.锟絎hen combined with Silicon Labs' Si3000 voice codec, the Si24xx data modems support handset, speakerphone (full or half-duplex), voice menu and answering machines, added the company. Developers can easily add telephony and voice functions to any embedded system, without the need for the dedicated voice processing ICs or host-based DSP software required by legacy approaches. The ICs are ideal for any system with telephony functions such as video phones and medical monitoring equipment.

In addition to offering a complete suite of ITU-T "V-dot" data communications, compression and error correction protocols, the device supports specialized protocols used in security and POS applications. Standard DTMF and user-programmable tone detection and generation give the Si24xx family the flexibility to support non-standard custom protocols through host software.

As part of Silicon Labs "green" solutions, the Si24xx ISOmodem family offers the industry's lowest power consumption in both active and standby modes, said the company. Operating from a single 3.3V power supply, ISOmodem chipsets draw very little power—56mW in normal operation (on-hook, idle). Sleep and wake-on-ring modes are available to reduce power consumption to 0.3mW and 15mW, respectively. This capability allows a system to appear to be always on while consuming very little power and still responding to events on the telephone line.

Si24xx ISOmodem ICs are available in a tiny 5 x 7mm QFN package, resulting in the smallest total board area for embedded modem designs, claimed Silicon Labs. Developers can use a small, low-cost 32kHz watch crystal instead of the larger, more expensive crystal typically used in embedded modems. The Si24xx devices also offer the option of using a serial peripheral interface in addition to UART and parallel interfaces, enabling resource sharing among multiple peripherals.

The Si24xx data modems support the patented architecture of the world's most widely adopted silicon data access arrangement (DAA) solution. Silicon Labs' global silicon DAAs deliver unmatched surge immunity without additional BOM cost, noted the company. One hardware design can support all speeds and meet worldwide compliance requirements.

Samples and production quantities of the Si24xx ISOmodem chipsets are available now. Depending on the maximum data rate, system-side package type and temperature range, ISOmodem/DAA chipset prices range from $6.44 to $11.43 in 10,000-unit quantities. Evaluation kits such as the Si2494-A-FM18-EVB are available for $150 each.