SI2457-C-FSR

Overview

The SI2457-C-FSR is a system-side network controller and processor IC from the ISOmodem family, designed for embedded modem applications. It supports data rates up to 56 kbps using V.90 protocols and operates with a 3.3 V supply voltage (3.0 V to 3.6 V range). The device features an integrated Direct Access Arrangement (DAA) providing over 6000 V capacitive isolation. It communicates via SPI or UART interfaces and utilizes a 4.915 MHz clock frequency. The component is housed in a 16-pin SOIC package and functions within a commercial temperature range of 0°C to +70°C.

Feature Summary

• Integrated Direct Access Arrangement (DAA) eliminates external transformers, relays, and opto-isolators.
• Supports global telephone line interface compliance with parallel phone detection capabilities.
• Firmware upgradeable architecture allowing protocol updates without hardware changes.
• Compatible with standard AT command sets and supports SMS/MMS functionality.

Applications

• Set-top boxes
• Point-of-sale terminals
• Text and video telephones
• Digital video recorders

Procurement Notes

Verify the specific ordering suffix 'FSR' against official Skyworks documentation to confirm package type and tape-and-reel availability. Confirm RoHS compliance status and moisture sensitivity level requirements prior to assembly. Check for end-of-life notifications as this chipset family may have limited production support.

Selection Notes

Select the SI2457 variant specifically when V.90 56 kbps download speeds are required, as lower variants like Si2434 only support up to 33.6 kbps. Ensure the design pairs this system-side IC with the appropriate line-side DAA device, such as the Si3018. Verify that the host processor supports the required SPI or UART interface timing specifications.

Part Context

This component belongs to the ISOmodem family of complete modem chipsets. It serves as the system-side processing unit, handling digital signal processing and protocol management. It is designed to work in conjunction with a line-side device to form a compact, low-component-count solution for PSTN connectivity.

Replacement Considerations

Publicly confirmed substitutes include other members of the ISOmodem family such as the SI2434-D-FS or SI2415-D-FS, though these offer reduced maximum data rates. Verify pin compatibility and firmware differences before substitution.