STMicroelectronics E-TDA7391PD

Overview

E-TDA7391PD from STMicroelectronics is a 32 W bridge-type Class AB audio power amplifier designed for high-power car radio applications. It delivers 32 W into 3.2 Ω at 14.4 V, features differential or single-ended inputs, fixed 30 dB gain, and integrated short-circuit/overtemperature protection. Used in automotive head units and booster stages where compact high-output amplification is required.

For engineers reviewing the E-TDA7391PD datasheet, E-TDA7391PD pinout, E-TDA7391PD application, or E-TDA7391PD equivalent, key selection criteria include output power vs. load impedance, clipping detection capability, programmable mute/standby timing, and PowerSO20 thermal performance in constrained automotive PCB layouts.

Technical Context

The TDA7391PD implements a fully complementary PNP/NPN bridge output stage enabling rail-to-rail swing without bootstrap capacitors. Its internal fixed-gain architecture (30 dB) eliminates external feedback networks, while the open-collector CD pin provides real-time 10% THD-based clipping detection for dynamic gain compression.

Standby and mute functions are independently controlled via CMOS-compatible logic-level inputs (ST-BY and MUTE), with programmable turn-on/off delay set by an external R–C network on SYNC and MUTE pins. Protection includes short-circuit (to GND, VS, or across load), overtemperature shutdown at 160 °C, load dump tolerance up to 50 V, and ESD robustness.

Key Specifications

Pinout & Package

Package: PowerSO20 (slug-up), thermally enhanced surface-mount package with exposed metal slug on top side for direct heatsink attachment. Pin count: 20. Mounting requires solder reflow per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-power automotive audio amplifier applications.

Compared with TDA7377A and TPA5560DAP, the E-TDA7391PD uniquely balances Class AB linearity, integrated diagnostics (CD pin), and 32 W output in a thermally optimized PowerSO20 (slug-up) package-making it optimal for space-constrained, high-fidelity automotive amplifiers requiring real-time signal integrity feedback.

Availability

E-TDA7391PD is available at Aetrix Electronics and suitable for car stereo head units, aftermarket audio boosters, automotive display audio systems, and commercial vehicle entertainment units requiring stable component supply across extended temperature and voltage ranges.

Supply support for E-TDA7391PD 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, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The TDA7xxx series is ST's dedicated automotive audio power amplifier product line, engineered specifically for high-fidelity, thermally robust, and fault-tolerant amplification in vehicle infotainment systems.

FAQ

What is the purpose of the CD (clipping detection) pin?

The CD pin is an open-collector output that goes low when output distortion reaches or exceeds 10% THD. It requires an external pull-up resistor to +VS and enables real-time gain compression or LED indicators without external measurement circuitry. This function is confirmed in Section 2 (Pins Description) and Table 5 (Electrical Characteristics) of the official ST datasheet (Doc ID 6326 Rev 5).

Can E-TDA7391PD operate from a 24 V supply?

No - the absolute maximum supply voltage is 28 V peak for 50 ms, but the recommended operating range is 8–18 V DC. Sustained 24 V operation exceeds the 18 V operating limit and risks permanent damage. A DC-DC buck converter must be used to regulate 24 V down to ≤18 V before connecting to +VS pins.

Why are there separate GND and S-GND pins?

GND (pins 1, 10, 11, 20) carries high-current return paths for the output stage and power supply, while S-GND (pin 12) serves as the quiet reference for the differential input stage. Separating them prevents switching noise from modulating the input signal, preserving CMRR (>65 dB) and minimizing audible hum in sensitive audio designs.

Is heatsinking required for 32 W continuous output?

Yes - although the PowerSO20 (slug-up) package has R_{th j-case} = 2 °C/W, achieving 32 W continuous output requires mounting the exposed slug to a heatsink with ≤3.5 °C/W total thermal resistance (case-to-ambient). Without heatsinking, junction temperature exceeds 150 °C within seconds at full power, triggering thermal shutdown.