SI2456-FT

Overview

The Skyworks Solutions Inc. SI2456-FT is a V.90, V.34, and V.32bis ISOmodem chipset with an integrated global Direct Access Arrangement (DAA). It provides a programmable line interface to meet worldwide telephone requirements using a single design. The Si2456 supports data rates up to 56 kbps full-duplex over the Public Switched Telephone Network (PSTN). The chipset integrates a DSP data pump, modem controller, on-chip RAM/ROM, analog front end, and DAA. It operates at a digital supply voltage of 3.3V and features both serial UART and parallel 8-bit interfaces for host communication.

Feature Summary

• Integrated global DAA providing capacitive isolation and programmable line interface for worldwide PTT compliance
• Supports ITU-T V.90, V.34, V.32bis protocols with automatic rate negotiation and error correction
• Includes built-in caller ID decode and call progress monitoring capabilities
• Firmware upgradeable via EEPROM interface without external ROM or RAM requirements

Applications

• Set-top boxes
• E-mail terminals
• Point-of-sale terminals
• Digital video recorders
• Security systems
• Remote monitoring

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type and temperature grade. Ensure compatibility with the required Si3015 companion chip as specified in the valid chipset combinations listed in the datasheet. Confirm that the component meets the intended environmental operating conditions for your application.

Selection Notes

Select the SI2456 variant when maximum download speeds up to 56 kbps are required. Consider the SI2433 or Si2414 if lower cost or power consumption is prioritized over high-speed connectivity, as they support reduced maximum rates of 33.6 kbps and 14.4 kbps respectively. All variants share identical feature sets and pinouts.

Part Context

The SI2456 belongs to the Silicon Laboratories ISOmodem family, which also includes the Si2433 and Si2414. These chips share the same physical footprint and functional architecture but differ primarily in their maximum supported data transmission rates. The Si2456 represents the high-performance tier of this embedded modem solution series.

Replacement Considerations

The Si2457 is a compatible alternative within the same family that adds support for V.22bis protocols alongside V.90 and V.34. The Si2494 offers V.92 and V.34 support. Verify firmware compatibility and register mapping before substituting these models.