W91031SG

Overview

The W91031 is a low-power CMOS integrated circuit designed for receiving Caller Identification physical layer signals per Bellcore and British Telecom specifications. It supports on-hook calling with caller ID messages and call waiting features. The device performs FSK demodulation of Bell 202 and CCITT V.23 standards at 1200 baud, detects dual-tone alert signals (CAS), and identifies ring bursts or line reversals. Operating voltage ranges from 3.0V to 5.5V with a typical standby current of 1μA. It utilizes a 3.579545 MHz crystal oscillator and offers two serial data interface modes for microcontroller integration.

Feature Summary

• Integrated FSK demodulator supporting Bell 202 and CCITT V.23 protocols
• Dual-tone alert signal detection for Bellcore CAS and BT idle/loop states
• Ring detector and line reversal identification capabilities
• Configurable 3-wire serial data interface with interrupt generation

Applications

• Bellcore Calling Identity Delivery (CID) systems
• British Telecom Calling Line Identity Presentation (CLIP) systems
• Feature phones and phone set adjunct boxes
• FAX machines and answering machines
• Computer Telephony Integration (CTI) systems

Procurement Notes

Verify the specific package variant required, as the datasheet lists both 24-pin 0.6 inch plastic DIP and 24-pin 0.3 inch plastic SOP options. Confirm that the supplier provides the original Winbond Electronics Corporation component rather than a generic equivalent, as pinouts and electrical characteristics are proprietary. Ensure the revision level matches the design requirements, noting the document is Revision A1.

Selection Notes

Select this component when designing telephony equipment requiring compliant Caller ID decoding without external demodulators. It is suitable for applications needing low power consumption due to its sleep mode capability. Ensure the host microcontroller can support either Mode 0 (device-initiated clock) or Mode 1 (MCU-initiated clock) for the FSK data interface based on system timing constraints.

Part Context

The W91031 is manufactured by Winbond Electronics Corporation, not Nuvoton Technology Corporation. While Nuvoton was formed from the logic IC division of Winbond, this specific analog telephony chip predates the Nuvoton spin-off and remains under the Winbond brand. It belongs to a family of dedicated Caller ID decoder ICs used in legacy and modern telephone infrastructure.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should verify compatibility with any alternative Caller ID decoder ICs by comparing FSK demodulation standards, tone detection frequencies, and pin configurations carefully.