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Home > Products > Integrated Circuits (ICs) > Linear > Audio Amplifiers

STMicroelectronics TDA7381

Name: TDA7381
Brand: STMicroelectronics
SKU: TDA7381
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TDA7381

Manufacturer:: STMicroelectronics

Category:: Audio Amplifiers

Package:: 25-Flexiwatt, Formed Leads

Datasheet:: TDA7381.pdf

Description:: IC AMP AB QUAD 30W 25FLEXIWATT

Quantity:: RFQ Add To RFQ list

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Inventory:3,893

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Product details

Overview

TDA7381 from STMicroelectronics is a quad-channel Class AB audio power amplifier in Flexiwatt25 package, designed for automotive radio systems. It delivers 4 × 25 W into 4 Ω (EIAJ), features integrated clipping detection, thermal shutdown protection, and diagnostics for output-to-GND/VS shorts - enabling robust fault monitoring in vehicle infotainment head units.

For engineers reviewing the TDA7381 datasheet, TDA7381 pinout, TDA7381 application, or TDA7381 equivalent, key selection considerations include rail-to-rail output swing without bootstrap capacitors, fixed 26 dB gain, CMOS-compatible standby/mute control, and diagnostic current-sinking output at pin 25 for real-time clipping and fault reporting.

Technical Context

The TDA7381 employs a fully complementary PNP/NPN output stage enabling rail-to-rail voltage swing and eliminating external bootstrap capacitors. Its internal SVR (supply voltage rejection) block biases all inputs and AC-GND at Vs/2, ensuring stable DC operating points across four independent channels.

It integrates a single open-collector diagnostics output (pin 25) that sinks current during clipping, thermal proximity, or output short conditions - differentiated by pulse width: short pulses indicate clipping, sustained low states indicate faults like thermal shutdown or shorts.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Power	4 × 25 W @ 4 Ω, EIAJ compliant; enables full-range audio drive for four-door car speakers without external heatsink oversizing.
Supply Voltage Range	13.2–14.4 V typical operation; supports automotive battery variations including cold-crank (down to 9 V) with automute activation.
THD+N	0.04 % @ 4 W, 1 kHz; ensures high-fidelity reproduction with minimal harmonic distortion in mid-bass and vocal bands.
Input Impedance	70–100 kΩ; compatible with standard preamp outputs and allows direct coupling via 0.1 µF AC-coupling capacitors.
Standby Current	≤100 µA; enables ultra-low-power sleep mode for head unit memory retention without draining battery.
Diagnostic Output	Open-collector sink at pin 25 (max 350 µA ON); provides hardware-level fault signaling without MCU polling overhead.
Thermal Resistance	R_{th j-case} = 1 °C/W; permits direct mounting to chassis ground plane for efficient heat dissipation in compact radio PCBs.

Pinout & Package

Package: Flexiwatt25 (vertical, 25-pin, thermally enhanced leadframe with exposed tab connected to pin 1). Pin 1 is electrically and mechanically tied to the internal heat slug and must be soldered to a large copper pour on the PCB for thermal and electrical grounding.

Pin/Terminal	Circuit Role	Design Meaning
1	Case Ground / Heat Slug	Primary thermal path and low-impedance power ground reference; must connect to PCB ground plane with ≥4 thermal vias.
2, 8, 18, 24	Channel Power Grounds	Dedicated GND returns per channel reduce crosstalk and prevent ground bounce between amplifiers.
3, 9, 19, 25	Outputs (CH1–CH4)	Class AB rail-to-rail outputs; each drives one speaker directly without external bootstrap components.
4, 10, 20, 26	Inverting Inputs	Internally biased at Vs/2; require matched input coupling caps (±10 % tolerance) for optimal SVR and pop-free switching.
5, 11, 21, 27	Non-inverting Inputs	Ground-referenced audio inputs; accept ±8 Vpk signals without clipping or degradation.
16	AC-GND	Common AC reference node for all four channels; connects to SVR network and must tie to signal ground near input caps.
22	Mute Input	CMOS-compatible active-low control; ≤1.5 V activates mute (≥80 dB attenuation); sourcing ≤16 µA allows RC filtering for pop suppression.
23	Standby Input	CMOS-compatible active-low control; ≤1.5 V enters standby (≤100 µA I_q); requires RC time constant <2.5 V/ms for pop-free transition.
25	Diagnostic Output	Open-collector current sink; pulses during clipping, latches low during thermal/short faults; max load = 1 kΩ pull-up.

Key Features

Feature	Design Value
Integrated Clipping Detector	Generates synchronized current pulses at pin 25 during saturation events - enables automatic gain reduction or bass roll-off before audible distortion occurs.
Four Independent Power Grounds	Pins 2/8/18/24 isolate return paths per channel, reducing inter-channel crosstalk to ≥70 dB and minimizing shared-impedance distortion.
Automute at Low Supply	Activates mute below ~9 V supply, preventing distorted audio during engine cranking without external undervoltage monitor circuitry.
No External Compensation Required	Stable into 4 Ω loads with no output R-C snubbers or compensation networks - reduces BOM count and PCB area vs. legacy quad amps.
Thermal Limiter with Soft Shutdown	Gradually reduces output power as junction temperature approaches 150 °C, avoiding abrupt cutoff and preserving audio continuity during thermal stress.

Applications

Car Stereo Head Unit

Aftermarket Infotainment System

Use Scenario: Integrated 4-channel amplifier in OEM or Tier-1 automotive head unit PCB.

IC Role / Device Role / Timing Role: Final-stage audio driver delivering full-range signals to front/rear door speakers with diagnostics feedback to MCU.

Use Value: Eliminates need for discrete protection ICs and external muting logic; diagnostics pin enables automated assembly-line wiring verification.

Use Scenario: Compact aftermarket radio replacement with digital signal processing and Bluetooth audio.

IC Role / Device Role / Timing Role: High-efficiency analog output stage synchronized to DSP mute commands and supply monitoring.

Use Value: Fixed 26 dB gain simplifies level matching with DAC outputs; low-noise floor (50 µV A-weighted) preserves dynamic range of compressed audio streams.

OEM Dashboard Audio Module

Marine Audio Control Unit

Use Scenario: Space-constrained dashboard-mounted audio module powering tweeters and midranges.

IC Role / Device Role / Timing Role: Quad-channel Class AB amplifier with thermal derating and load-dump immunity for 12 V vehicle systems.

Use Value: Withstands 50 V peak load-dump transients (t = 50 ms); R_{th j-case} = 1 °C/W enables conduction cooling through metal chassis mount.

Use Scenario: Waterproof marine audio system requiring robust fault handling in humid, salt-exposed environments.

IC Role / Device Role / Timing Role: Fault-tolerant amplifier with short-circuit diagnostics for speaker wiring integrity checks during startup.

Use Value: Diagnostics pin distinguishes clipping (short pulses) from output shorts (sustained low), enabling targeted error logging and user alerts.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TDA7388	Higher output (4 × 41 W @ 4 Ω), includes I²C control interface and enhanced thermal management.	Requires microcontroller integration for configuration; not pin-compatible due to added control pins and different package (Flexiwatt27).	Select when programmable gain, channel bridging, or remote diagnostics via bus are required - not for drop-in replacement.
STA559BW	Digital input (I²S), Class D topology, 4 × 45 W @ 4 Ω, integrated DSP and protection.	Replaces analog signal chain with digital audio interface; demands layout changes for EMI mitigation and inductor-based output filters.	Choose for higher efficiency (>80 %) and feature-rich audio processing - only viable if system architecture supports digital audio domain.

Compared with TDA7388 and STA559BW, the TDA7381 offers lowest BOM cost and simplest analog integration for fixed-gain, diagnostics-enabled 25 W/channel designs - ideal where reliability, thermal simplicity, and proven field performance outweigh programmability or efficiency gains.

Availability

TDA7381 is available at Aetrix Electronics and suitable for automotive head units, aftermarket infotainment systems, and marine audio modules requiring stable component supply, long-lifecycle support, and production-grade automotive qualification.

Supply support for TDA7381 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, specializing in automotive, industrial, and power management ICs with broad manufacturing and quality certifications.

The TDA7381 belongs to ST's automotive audio amplifier product line, engineered specifically for cost-sensitive, high-reliability car radio applications demanding integrated diagnostics, thermal resilience, and minimal external components.

FAQ

What is the minimum supply voltage for reliable operation with automute enabled?

The TDA7381 activates automute when supply voltage drops below approximately 9 V, preventing distorted audio during engine cranking. Stable operation begins at 13.2 V (15 W/channel), and the device remains functional down to 8 V in standby mode with ≤100 µA quiescent current.

Can the TDA7381 drive 2 Ω loads?

No - the TDA7381 is rated and characterized only for 4 Ω loads per channel. Driving 2 Ω loads exceeds absolute maximum ratings for output current (3 A repetitive) and thermal dissipation, risking premature thermal shutdown or latch-up. ST does not specify or guarantee operation below 4 Ω.

How is the clipping detector output used in practice?

Pin 25 sinks current during clipping events, producing short pulses synchronized to waveform saturation. Designers typically use an RC integrator (e.g., 10 kΩ + 100 nF) to convert pulses into a DC voltage that triggers automatic gain reduction or bass attenuation in downstream DSP or analog circuitry.

Is the Flexiwatt25 package RoHS-compliant and halogen-free?

Yes - the TDA7381 is offered in ECOPACK®-compliant Flexiwatt25 packages meeting RoHS Directive 2011/65/EU and halogen-free requirements per IEC 61249-2-21. ST's official ECOPACK documentation confirms compliance grade "ECOPACK2" for this part number.

TDA7381 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 25-Flexiwatt, Formed Leads

Packaging:: Tube

Product Status:: Active

Type:: Class AB

Output Type:: 4-Channel (Quad)

Max Output Power x Channels @ Load:: 30W x 4 @ 4Ohm

Voltage - Supply:: 8V ~ 18V

Features:: Mute, Short-Circuit and Thermal Protection, Standby

Mounting Type:: Through Hole

Operating Temperature:: -

Grade:: -

Qualification:: -

Supplier Device Package:: 25-Flexiwatt (Vertical)

TDA7381 FAQ

1.How can I place an order for TDA7381 through Aetrix?

Please submit a Request for Quotation (RFQ) for TDA7381 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TDA7381 reliable?

The price and inventory of TDA7381 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TDA7381 is usually 5 days.

3.What payment methods are accepted for TDA7381?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TDA7381 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TDA7381?

TDA7381 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TDA7381 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TDA7381?

For technical support, including TDA7381 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TDA7381 requirements.

6.How does Aetrix verify that TDA7381 is sourced from the original manufacturer or authorized distributors?

All TDA7381 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TDA7381 meets industry standards.

7.What is the process for return or replacement of TDA7381?

All TDA7381 units undergo pre-shipment inspection (PSI). If there is an issue with TDA7381, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TDA7381 part is unused and in its original packaging.

Return procedure for TDA7381:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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