SI2435-B-FTR

Overview

The SI2435-B-FTR is a V.34 fax modem integrated circuit manufactured by Skyworks Solutions Inc., originally developed by Silicon Laboratories. It operates as part of the ISOmodem chipset with the Si3018 DAA, supporting data rates from 14,400 bps to 33,600 bps over PSTN lines. The device functions within a digital supply voltage range of 3.0 V to 3.6 V and supports an operating temperature range of 0°C to 70°C for F-Grade specifications. It integrates a DSP, modem controller, codec, and silicon-based direct access arrangement (DAA), eliminating the need for external isolation transformers or relays.

Feature Summary

• Integrated third-generation silicon direct access arrangement (DAA) providing global telephone line interface compliance without external isolation components.
• Supports ITU-T T.31 Class 1 AT commands for G3 and Super G3 fax communication with automatic rate negotiation up to 33.6 kbps.
• Features built-in caller ID decoding for multiple global standards including Bellcore, ETSI, UK, and Japanese protocols.
• Includes data/fax/voice discriminator capabilities and DTMF tone generation/detection for advanced call management.

Applications

• Fax machines
• Fax telephones
• Multifunctional printers
• Fax servers

Procurement Notes

Verify the specific suffix 'B-FTR' against official Skyworks or Silicon Laboratories documentation to confirm tape-and-reel packaging and lead-free status. Ensure compatibility with the required Si3018 DAA component for complete functionality. Confirm that the F-Grade temperature rating meets the target application environment requirements before finalizing procurement.

Selection Notes

Select this component for applications requiring a compact, globally compliant fax solution with minimal external bill of materials. The integrated DAA reduces board space significantly compared to discrete solutions. Consider the Si2417 variant if only standard G3 fax speeds up to 14.4 kbps are required, or the Si2435 if Super G3 and V.8 call establishment features are necessary.

Part Context

This part belongs to the ISOmodem family of embedded fax modems. It is designed to replace traditional multi-chip fax solutions by integrating the modem controller, DSP, codec, and analog front-end into a single package. The chipset architecture simplifies design by removing the need for separate ROM/RAM and complex analog filtering circuits typically associated with PSTN interfaces.

Replacement Considerations

The Si2417 serves as a lower-speed alternative within the same chipset family, supporting up to 14.4 kbps. Designers should verify pinout compatibility and firmware requirements when substituting between Si2435 and Si2417 variants, as feature sets such as Super G3 support differ.