STMicroelectronics E-TDA7479ADTR

Overview

E-TDA7479ADTR from STMicroelectronics is a single-chip RDS (Radio Data System) demodulator and 8th-order 57 kHz bandpass filter for FM radio receivers. It performs fully digital RDS signal recovery per EBU specifications, delivers synchronized 1187.5 Hz RDCL clock and parallel RDDA data outputs, and provides ARI (Announcement Ready Indication) and signal quality (QUAL) status signals. Used in automotive and consumer FM tuners requiring embedded RDS decoding.

For engineers reviewing the E-TDA7479ADTR datasheet, E-TDA7479ADTR pinout, E-TDA7479ADTR application, or E-TDA7479ADTR equivalent, this device supports crystal-free RDS demodulation with internal 4.332 MHz oscillator, adjustable 57 kHz filter center frequency, and configurable external clock input via OSEL/FSEL pins - critical for tuner system integration and EMI-sensitive designs.

Technical Context

The TDA7479 integrates a cascaded antialiasing + switched-capacitor 8th-order bandpass filter centered at 57 kHz (±0.5 kHz), followed by a digital PLL-based biphase demodulator that recovers RDDA data and RDCL clock. The demodulator operates without external timing components and supports three selectable oscillator frequencies (4.332/8.664/17.328 MHz) via FSEL configuration.

It features dual output signaling: QUAL (open-drain, high = good RDS lock) and ARI (active-high indication of RDS+ARI or ARI-only presence), plus T57 test output (57 kHz clock). All inputs (EXTRES, TM, FSEL) include internal pull-downs; OSEL has internal pull-up, enabling flexible oscillator mode selection between internal crystal and external sinusoidal drive.

Key Specifications

Pinout & Package

Package: TSSOP16 (JEDEC MO-153-AB), 5.0 mm × 6.4 mm body, 0.65 mm pitch, ECOPACK® lead-free construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si4702-C10-GM, E-TDA7479ADTR offers simpler integration into analog IF-based systems without firmware dependencies; compared with STA608A, it adds ARI detection and flexible oscillator configuration-critical for tuner differentiation and EMI reduction.

Availability

E-TDA7479ADTR is available at Aetrix Electronics and suitable for automotive FM tuner modules, consumer stereo receivers, portable hybrid radios, and aftermarket car audio head units requiring stable component supply and ECOPACK® compliance.

Supply support for E-TDA7479ADTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, mixed-signal, power, and microcontroller products for industrial, automotive, and consumer markets.

The TDA7479 belongs to ST's audio signal processing product line, engineered specifically for high-fidelity FM radio subsystems requiring precise RDS subcarrier recovery, low EMI, and minimal external component count.

FAQ

What crystal frequency is required for standard operation?

E-TDA7479ADTR operates with a 4.332 MHz crystal by default when FSEL is left open and OSEL is tied to VS. Optional 8.664 MHz and 17.328 MHz crystals are supported via FSEL pin configuration. C1 = 27 pF and C2 = 47 pF are recommended for the 4.332 MHz case per ST's mechanical design guide.

Can the device accept an externally generated 57 kHz clock instead of using the internal oscillator?

No - the TDA7479 does not accept a direct 57 kHz clock. Its oscillator interface supports only 4.332 MHz, 8.664 MHz, or 17.328 MHz crystals or external sine-wave inputs at those frequencies. The internal PLL derives the 57 kHz filter clock and 1187.5 Hz RDCL from the selected master oscillator.

How is the ARI output used in a practical tuner design?

The ARI pin asserts high when either RDS+ARI or ARI-only signals are detected, enabling firmware to mute audio or flash a visual indicator during traffic announcements. Its logic state is independent of QUAL, allowing separate handling of announcement readiness versus RDS data validity.

Is the TSSOP16 package thermally adequate for continuous operation in automotive dashboards?

Yes - the TSSOP16 package has a junction-to-case thermal resistance of 160 °C/W and is rated for −40°C to +85°C operation. With typical 11 mA supply current at 5 V, power dissipation remains below 60 mW, ensuring safe thermal margin even in sealed enclosure environments.