STMicroelectronics TDA7808-ZSX

Overview

TDA7808-ZSX from STMicroelectronics is an AEC-Q100 qualified quad-channel Class-AB+SB-I automotive audio power amplifier with integrated 24-bit digital input interface (I2S/TDM), 115 dB A-weighted dynamic range, and start-stop battery compatibility down to 6 V. It delivers 4 × 27 W into 4 Ω at 14.4 V/1 kHz/10% THD and supports sample rates up to 192 kHz in automotive infotainment head units.

For engineers reviewing the TDA7808-ZSX datasheet, TDA7808-ZSX pinout, TDA7808-ZSX application, or TDA7808-ZSX equivalent, key selection considerations include its PowerSO-36 (slug-up) package, I²C-addressable mode control (four selectable addresses), independent front/rear clipping detection, SB-I high-efficiency operation, and thermal protection with R_th(j-case) = 1 °C/W.

Technical Context

The TDA7808 integrates a full 24-bit D/A converter, programmable PLL locking to 64×F_s, and four fully balanced bridge-output stages using BCD process technology. Its SB-I (Switched-Bias Improved) architecture dynamically modulates supply rails to reduce dissipation by up to 50% versus conventional Class AB under real-world audio signals.

It features dual-domain regulation (A3V3 analog, D3V3 digital), CMOS-compatible enable (STBY), open-drain diagnostic output (CD/DIAG), and flexible serial audio interface supporting I2S, TDM-4ch, TDM-8ch, and TDM-16ch (8+8) formats - all configurable via I²C at 1.8 V or 3.3 V logic levels.

Key Specifications

Pinout & Package

Package: PowerSO-36 (slug-up), thermally enhanced exposed metal tab for direct heatsink attachment. Pin count: 36 leads, including 4 dedicated power ground pins (PWGND1–4), dual supply rails (VCC12/VCC34), and redundant TAB connections (pins 1, 18, 19, 36) for low-inductance grounding.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-channel automotive digital-input amplifier applications.

Compared with TDA7808-ZSX, TDA7804TR sacrifices diagnostic capability and high-sample-rate flexibility for lower BOM cost, while MAX9879AEWP+ trades start-stop compatibility for higher Class D efficiency - making TDA7808-ZSX uniquely suited for modern micro-hybrid vehicle audio systems requiring both low-voltage resilience and embedded diagnostics.

Availability

TDA7808-ZSX is available at Aetrix Electronics and suitable for automotive infotainment head units, rear-seat entertainment systems, and ADAS audio alert subsystems requiring stable component supply across extended vehicle production lifecycles.

Supply support for TDA7808-ZSX 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-grade analog, power, and microcontroller solutions with AEC-Q100 qualification rigor.

The TDA7808 belongs to ST's automotive audio power amplifier product line, engineered specifically for start-stop compatible, digitally interfaced infotainment systems demanding high fidelity, thermal resilience, and functional safety-aware diagnostics.

FAQ

What is the function of the CD/DIAG pin on TDA7808-ZSX?

The CD/DIAG pin is an open-drain output that asserts low during channel clipping or thermal warning events. It supports wired-OR connection of multiple amplifiers for centralized fault monitoring and does not require external pull-up in standard configurations due to internal 10 kΩ pull-up. Its timing aligns with audio frame boundaries for deterministic DSP response.

Does TDA7808-ZSX support I²C communication at 1.8 V logic levels?

Yes - the SDA and SCL pins are 1.8 V/3.3 V tolerant with VIH(min) = 0.7×VDD and VIL(max) = 0.3×VDD. When powered by 3.3 V digital supplies (D3V3), it accepts 1.8 V I²C signals directly without level shifters, enabling seamless integration with low-voltage application processors in modern head units.

How does SB-I efficiency differ from standard Class AB or Class D operation?

SB-I is ST's proprietary switched-bias architecture that dynamically adjusts output stage supply rails based on instantaneous signal envelope - unlike fixed-rail Class AB or PWM-based Class D. This reduces average power dissipation by up to 50% under real music signals while retaining Class AB's linearity and low EMI, eliminating need for large LC filters.

Can TDA7808-ZSX drive 2 Ω loads?

No - the device is characterized and guaranteed only for 4 Ω and higher loads per channel. Driving 2 Ω loads exceeds absolute maximum ratings for output current and junction temperature, triggering thermal shutdown. ST specifies 4 Ω minimum load impedance in Table 6 and warns against lower impedances in Section 3.1 Absolute Maximum Ratings.