Analog Devices Inc./Maxim Integrated 73M1822-IM/F

Overview

The 73M1822-IM/F from Teridian Semiconductor is a single-package silicon Data Access Arrangement (DAA) IC for PSTN-connected soft modems and voice applications. It integrates codec, line interface, isolation barrier control, and MAFE serial interface functions; supports V.92 (56 Kbps), 7.2–16 kHz configurable sampling, 3.3 V operation, and achieves 4–5 kV isolation using an external pulse transformer. It enables globally compliant low-cost modem designs in industrial temperature range (−40°C to +85°C).

For engineers reviewing the 73M1822-IM/F datasheet, 73M1822-IM/F pinout, 73M1822-IM/F application, or 73M1822-IM/F equivalent, key selection considerations include PSTN termination configurability, THD (−80 dB), 16-bit codec resolution, MAFE master/slave/daisy-chain interface support, and integrated billing tone rejection and polarity reversal detection.

Technical Context

The 73M1822-IM/F implements a fully integrated analog front end with digital signal processing for PSTN line-side interfacing. It features a programmable DC termination circuit supporting global PTT standards (FCC, ETSI ES 203 021-2, JATE), configurable AC impedance matching, and on-chip ring detection, hook switch control, and parallel pickup sensing.

Its MAFE serial interface operates in master, slave, or daisy-chain mode with frame-synchronized data transfer; clock management includes PLL-based sample rate synthesis from 9–40 MHz reference clocks or 9–27 MHz crystals. The device uses an external pulse transformer for galvanic isolation and barrier power delivery.

Key Specifications

Pinout & Package

The 73M1822-IM/F is housed in an 8×8 mm, 42-pin QFN package with exposed thermal pad (RoHS-compliant, lead-free). Pinout is defined in datasheet Figure 6 and Table 5.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DAA applications.

Compared with Si3050-C-FM and CS5532-ASZ, the 73M1822-IM/F uniquely combines certified global DAA compliance, barrier-powered operation, and MAFE interface in a single package - reducing design risk, certification effort, and component count for PSTN-connected embedded systems.

Availability

The 73M1822-IM/F is available at Aetrix Electronics and suitable for V.92 modems, fax/MFP devices, and point-of-sale terminals requiring stable component supply, long-term lifecycle support, and industrial temperature operation.

Supply support for 73M1822-IM/F includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Teridian Semiconductor was a fabless analog/mixed-signal IC company specializing in highly integrated communications and energy measurement solutions before its acquisition by Maxim Integrated in 2011.

The 73M1822-IM/F belongs to Teridian's MicroDAA™ family, designed specifically to replace discrete DAA implementations with a single-chip, globally compliant solution for soft modems and voice-enabled embedded systems.

FAQ

What is the primary function of the 73M1822-IM/F in a modem system?

The 73M1822-IM/F serves as a complete silicon Data Access Arrangement (DAA), integrating PSTN line interface, 16-bit codec, isolation barrier control, and MAFE serial interface. It replaces traditional discrete DAA circuits and enables globally compliant soft modem designs up to V.92 (56 Kbps) without external analog front-end components. The 73M1822-IM/F handles all critical line-side functions including DC termination, ring detection, polarity reversal sensing, and billing tone rejection.

Does the 73M1822-IM/F require an external pulse transformer, and why?

Yes, the 73M1822-IM/F requires an external pulse transformer to achieve galvanic isolation between the PSTN line and system ground. This transformer provides 4–5 kV isolation per datasheet specification and enables barrier-powered operation - delivering power across the isolation boundary to sustain functionality under weak loop current conditions. The 73M1822-IM/F drives the transformer secondary directly via its TIP and RING pins.

What sample rates does the 73M1822-IM/F support, and how are they configured?

The 73M1822-IM/F supports configurable sample rates from 7.2 kHz to 16 kHz, covering V.90/V.92, G.711, and other voice/data standards. Sample rate is set via internal PLL registers using either a 9–40 MHz reference clock or a 9–27 MHz crystal oscillator. Configuration is performed through the MAFE interface using documented clock generation register settings (e.g., Tables 32–36 in DS_1x22_001), allowing runtime adaptation to host processor requirements.

How does the 73M1822-IM/F handle global regulatory compliance for PSTN connections?

The 73M1822-IM/F achieves global compliance (FCC Part 68, ETSI ES 203 021-2, JATE, NET4) through programmable DC and AC termination profiles stored in on-chip registers. These settings configure loop current regulation, impedance matching, and hybrid cancellation to meet region-specific PTT requirements without hardware modification. The 73M1822-IM/F also integrates detectors for over-voltage, under-voltage, and over-current events to ensure fail-safe line behavior.

Can the 73M1822-IM/F operate in daisy-chain configurations with other devices?

Yes, the 73M1822-IM/F supports daisy-chain operation via its MAFE serial interface. In this mode, multiple 73M1822-IM/F or compatible devices (e.g., 73M1922 variants) share a single SCLK and FS line while using individual SDATA lines, enabling multi-line or multi-channel PSTN interface designs. Timing diagrams and register configuration for daisy chaining are specified in Sections 8.6 and 8.7 of the datasheet, and the 73M1822-IM/F must be assigned a unique device address in the chain.