FX604D4

Overview

The FX604D4 is a low-power CMOS integrated circuit designed for V.23 compatible modem applications, supporting full-duplex asynchronous data transmission and reception at 1200 bits/sec with an optional 75 bits/sec back channel. It operates on a 3.0V to 5.5V supply, drawing 1.0mA typically at 3V, and features a 'Zero-Power' mode consuming 1μA. The device includes an internal oscillator requiring a 3.579545MHz crystal, optional line equalization, and data retiming capabilities to interface directly with microcontrollers without a UART. It conforms to CCITT V.23 and ETSI specifications.

Feature Summary

• Supports full-duplex 1200 bits/sec and optional 75 bits/sec back channel communication compliant with V.23 standards.
• Integrates receive path line equalization controlled by an external logic level to attenuate out-of-band noise.
• Provides optional data retiming functions for both transmit and receive paths to eliminate the need for a separate UART in the host microcontroller.
• Features a 'Zero-Power' mode that removes power from internal circuitry, achieving ultra-low standby current consumption.

Applications

• Telephone telemetry systems requiring low power consumption.
• Portable terminal devices powered by low voltage sources.
• Line-powered communication equipment utilizing minimal operating current.

Procurement Notes

Verify component authenticity through authorized CML Microcircuits distributors or official channels. Confirm package type matches the D4 suffix for 16-pin SOIC. Check RoHS compliance status against current manufacturing revisions. Ensure ordering documentation specifies the correct temperature range for the intended environment.

Selection Notes

Select the FX604D4 when a V.23 compatible solution with integrated data retiming is required to simplify microcontroller design. Choose this part over variants lacking equalization if line conditions require group delay correction. Verify that the system clock can be provided via the XTAL/CLOCK pin using a standard 3.579545MHz crystal. Consider the 16-pin SOIC package constraints for PCB layout.

Part Context

The FX604 series represents a family of low-power CMOS modems from CML Microcircuits. The FX604D4 specifically denotes the 16-pin Small Outline Integrated Circuit (SOIC) package variant. This prefix distinguishes it from earlier MX-series products and later CMX-series branding, though silicon remains consistent across these naming conventions within the same functional generation.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult CML Microcircuits directly for obsolescence management or equivalent alternative recommendations.