73M1903-IM/F

Overview

The Analog Devices/Maxim Integrated 73M1903 is a modem analog front-end (AFE) IC designed for PSTN communications. It features fully differential hybrid driver outputs and receive pins, enabling high-performance signal-to-noise ratios when paired with standard transformers. The device supports soft modem and DSP-based implementations up to V.92 (56 kbps) with programmable sample rates ranging from 7.2 kHz to 14.4 kHz. It operates on a single 3.0 V to 3.6 V supply with 5 V tolerant I/O and includes an integrated reference clock circuit accepting crystals from 9-27 MHz or external clocks up to 40 MHz.

Feature Summary

• Supports V.92 (56 kbps) performance with programmable sample rates between 7.2 kHz and 14.4 kHz.
• Fully differential transmitter and receiver paths compatible with transformer-based Direct Access Arrangements (DAA).
• Integrated reference clock circuit accepts crystal frequencies of 9-27 MHz or external references up to 40 MHz.
• Host synchronous serial interface compatible with commercial DSPs and processors.

Applications

• Set Top Boxes
• Personal Video Recorders (PVR)
• Multifunction Peripherals (MFP)
• Fax Machines
• Internet Appliances

Procurement Notes

Verify the specific package variant required, as the 73M1903 is available in both 32-pin QFN and 20-pin TSSOP configurations. Confirm that the selected part number aligns with the necessary GPIO availability, noting that certain digital I/O pins are exclusive to the 32-pin QFN option. Ensure compliance with industrial temperature range specifications (-40°C to +85°C) if operating in harsh environments.

Selection Notes

Select the 73M1903 for designs requiring a cost-effective AFE solution that eliminates dedicated crystal oscillators through its flexible clock input range. Choose the 32-pin QFN package if software-defined GPIO functionality is required, whereas the 20-pin TSSOP offers a compact alternative without GPIO expansion. Ensure the host processor supports the required synchronous serial interface timing and frame synchronization modes.

Part Context

The 73M1903 belongs to the Teridian modem AFE family, engineered to simplify system integration for voice communication devices. It serves as a bridge between digital baseband processors and analog telephone lines, providing the necessary signal conditioning and driving capabilities for standard PSTN interfaces while maintaining low power consumption through configurable sleep modes.

Replacement Considerations

The datasheet indicates pin compatibility with the 73M2901CL/CE modems. Designers replacing legacy components should verify electrical parameter alignment and register map differences to ensure seamless integration without hardware redesign.