STMicroelectronics TDA7461NDTR

Overview

TDA7461NDTR from STMicroelectronics is a fully integrated car radio signal processor IC combining audio processing, stereo decoding, noise blanking, and multipath detection in a single SO-28 package. It delivers programmable bass/treble (±14 dB), 79 dB volume attenuation, 15 dB loudness boost, and <15 µV output noise at 9 V supply - enabling high-fidelity FM/AM/CD/cassette audio processing in automotive head units without external passive components.

For engineers reviewing the TDA7461NDTR datasheet, TDA7461NDTR pinout, TDA7461NDTR application, or TDA7461NDTR equivalent, this device supports I²C-programmable filter coefficients, soft-mute timing control, stereo blend adjustment, and multipath-aware signal conditioning for legacy automotive infotainment systems requiring analog front-end integration and ESD-hardened operation.

Technical Context

The TDA7461NDTR implements a switched-capacitor architecture with BiCMOS process technology to achieve low distortion (<0.01% THD+N) and low noise (9–15 µV RMS) across its audio processor and stereo decoder blocks. Its I²C interface enables real-time configuration of 2nd-order bass/treble filters, loudness center frequency (200–400 Hz), and soft-mute time constants (0.48 ms to 600 ms).

It integrates a full stereo decoder with pilot tone detection, de-emphasis, field-strength control, and stereo blend; a noise blanker with automatic threshold control (ATC) and over-deviation detection; and a multipath detector with dedicated MPIN/MPOUT pins - all operating from a single 7.5–10 V supply with 25–35 mA typical current draw.

Key Specifications

Pinout & Package

SO-28 surface-mount package (17.9 mm × 7.6 mm, 1.27 mm pitch) with exposed thermal pad; compliant with ECOPACK® environmental standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar car radio signal processor applications.

Compared with TDA7461NDTR, TDA7462DTR offers measurable SNR improvement and automotive qualification but requires minor register map updates; STA559BW replaces analog signal conditioning with digital flexibility at the cost of increased MCU dependency and board complexity.

Availability

TDA7461NDTR is available at Aetrix Electronics and suitable for FM/AM radio head units, CD/cassette audio preprocessing, automotive antenna diversity systems, and in-car diagnostic audio monitoring requiring stable component supply and long-lifecycle support.

Supply support for TDA7461NDTR 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, specializing in automotive, industrial, and power management ICs with broad manufacturing scale and automotive qualification expertise.

The TDA7461NDTR belongs to ST's automotive audio processor product line, designed specifically for cost-sensitive, high-reliability analog signal conditioning in legacy car radio architectures where minimal external components and I²C configurability are critical.

FAQ

Is the TDA7461NDTR still recommended for new designs?

No - STMicroelectronics classifies TDA7461NDTR as "Not For New Design" (NFND) as of January 2009. It remains in production for legacy program continuity but lacks AEC-Q100 qualification and modern EMI/EMC compliance features. New projects should evaluate TDA7462DTR or digital alternatives unless maintaining exact form-fit-function replacement is mandatory.

What is the function of the CREF pin and what capacitor value is required?

The CREF pin connects to an external capacitor that sets the internal switched-capacitor clock frequency and directly influences filter cutoff accuracy. ST specifies a 100 nF ±10% ceramic capacitor between CREF and GND; deviation beyond ±10% causes measurable shift in bass/treble center frequencies and loudness response.

Can the TDA7461NDTR operate from a 5 V supply?

No - the absolute maximum supply voltage is 10.5 V, but the minimum functional voltage is 7.5 V per Table 4. Operation below 7.5 V causes undefined behavior in the stereo decoder PLL, noise blanker threshold tracking, and I²C interface logic levels; 9 V is the recommended nominal supply for full specification compliance.

How does the multipath detector interface with external circuitry?

The multipath detector uses dedicated pins MPIN (input) and MPOUT (open-drain output). MPIN accepts a filtered RF-derived signal (typically from tuner AGC or IF stage); MPOUT asserts low when multipath exceeds threshold, enabling direct connection to MCU GPIO or comparator inputs without pull-up resistors due to internal 70–100 kΩ pull-up.