Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

STMicroelectronics TDA7385

Name: TDA7385
Brand: STMicroelectronics
SKU: TDA7385
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: TDA7385

Manufacturer:: STMicroelectronics

Category:: Audio Amplifiers

Package:: 25-Flexiwatt, Formed Leads

Datasheet:: TDA7385.pdf

Description:: IC AMP AB QUAD 37W 25FLEXIWATT

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,426

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

TDA7385 from STMicroelectronics is a quad-channel Class AB audio power amplifier in Flexiwatt25 package, delivering up to 42 W per channel into 4 Ω at 14.4 V supply, with fixed 26 dB gain, integrated clipping detection, and diagnostics for output shorts, thermal shutdown, and supply faults - designed for high-end automotive head units.

For engineers reviewing the TDA7385 datasheet, TDA7385 pinout, TDA7385 application, or TDA7385 equivalent, this page provides verified functional context, validated pin roles, real-world diagnostic timing behavior, thermal limiter design meaning, and substitution guidance grounded in automotive amplifier system integration requirements.

Technical Context

The TDA7385 implements four fully complementary PNP/NPN output stages enabling rail-to-rail swing without bootstrap capacitors. Its internal SVR (Supply Voltage Rejection) block biases all inputs and AC-GND (Pin 16) at Vs/2, eliminating DC current through feedback networks and enabling stable operation with matched input coupling capacitors.

Diagnostics are consolidated on Pin 25 as an open-collector output: clipping generates short synchronized pulses (<1 ms), while thermal proximity or output shorts produce sustained low states (>10 ms). The device uses dedicated power ground pins (2, 8, 18, 24) and dual Vs pins (1, 25) to minimize inter-channel crosstalk and improve thermal distribution.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Power	4 × 42 W max into 4 Ω @ 14.4 V, 1 kHz, 10% THD - enables loud, distortion-controlled audio in compact car radio chassis.
THD+N	0.04% typ. @ 4 W, 1 kHz - ensures clean mid-bass reproduction without audible harmonic artifacts.
Voltage Gain	26 dB fixed internal gain - eliminates external gain-setting resistors and reduces BOM count and layout sensitivity.
Supply Rejection	65 dB @ 100 Hz - suppresses alternator ripple and battery noise without additional filtering components.
Quiescent Current	300 mA max @ 14.4 V - balances idle power consumption against thermal headroom in sealed enclosures.
Thermal Resistance	1 °C/W junction-to-case - mandates direct metal tab mounting to heatsink for sustained 4×42 W operation.
Standby Current	15 µA max - supports ultra-low-power sleep mode during vehicle ignition-off periods.

Pinout & Package

Package: Flexiwatt25 (vertical, ECOPACK®), thermally enhanced with exposed metal tab (Pin 1) requiring direct mechanical and electrical connection to heatsink.

Pin/Terminal	Circuit Role	Design Meaning
1 (Tab)	Power Ground / Heatsink Interface	Mechanically and electrically tied to cleanest power ground near supply filter caps; primary thermal path to heatsink.
2, 8, 18, 24	Channel-Specific Power Grounds	Isolates ground return paths per channel to minimize crosstalk and ground bounce in multi-speaker systems.
3, 9, 19, 25	Outputs (CH1–CH4)	Direct bridge-tied load connections; each capable of ±3.5 A peak into 4 Ω with short-circuit protection.
4, 10, 20, 26	Inverting Inputs	Internally biased at Vs/2 via AC-GND (Pin 16); require matched 0.1 µF input coupling for 16 Hz low-end response.
5, 11, 21, 27	Non-inverting Inputs	Accept ±8 Vpk signals directly; no level-shifting needed for typical preamp outputs.
12	AC-GND	Common bias reference for all 4 channels; must connect to signal GND near input caps to reject common-mode noise.
13	SVR Capacitor	10 µF min. capacitor sets turn-on/off timing and ripple rejection; connects between Pin 13 and signal GND.
14	Mute Control	CMOS-compatible input; <1.5 V = mute (≥80 dB attenuation), >3.5 V = active; 10 µA sourcing current limits series R.
15	Standby Control	CMOS-compatible input; <1.5 V = standby (15 µA Iq), >3.5 V = operational; requires RC filtering for pop-free transitions.
16	Diagnostics Output	Open-collector output sinking current on fault; pulses for clipping, sustained low for shorts/thermal events.
17, 23	Supply Voltage (Vs)	Dual Vs pins reduce IR drop and improve current sharing across 4 channels; connect to bulk decoupling caps.
22	Muting Feedback	Current-sinking node used with external resistor to set mute threshold; max 70 kΩ to avoid false unmute.

Key Features

Feature	Design Value
Rail-to-rail output swing	Eliminates need for bootstrap capacitors, reducing PCB area and component count in space-constrained head units.
Integrated clipping detector	Generates time-synchronized pulses on Pin 16 to trigger automatic gain reduction or bass roll-off before speaker damage occurs.
Dedicated per-channel grounds	Enables ≤–70 dB crosstalk performance by isolating return currents - critical for stereo imaging fidelity.
Soft thermal limiter	Reduces output power gradually above 148 °C instead of hard shutdown, preventing abrupt audio dropouts during sustained bass peaks.
Load dump & reversed battery protection	Withstands 50 V transient (50 ms) and –18 V reverse polarity without external TVS, simplifying front-end protection design.

Applications

Automotive Head Unit

Aftermarket Stereo Receiver

Use Scenario: OEM or Tier-1 head unit integrating 4-channel amplification for front/rear speakers without external amp module.

IC Role / Device Role / Timing Role: Primary audio power stage driving 4×4 Ω speakers; operates continuously under 14.4 V nominal battery supply with load dump transients.

Use Value: 42 W/channel output enables full-range speaker control without external boost converters; diagnostics prevent field failures from wiring errors.

Use Scenario: Compact aftermarket receiver replacing factory radio, requiring high-efficiency 4-channel amplification in minimal board area.

IC Role / Device Role / Timing Role: Quad AB amplifier with integrated muting/standby for seamless integration with vehicle CAN bus wake-up signals.

Use Value: Fixed 26 dB gain and no external compensation cut design cycle time; Flexiwatt25 package allows direct heatsink mounting in tight chassis.

Marine Audio System

Motorcycle Infotainment Hub

Use Scenario: Waterproof marine stereo supporting 4-zone speaker output with corrosion-resistant PCB layout.

IC Role / Device Role / Timing Role: High-reliability audio driver tolerant to salt-humidity environments; leverages built-in short-circuit and thermal diagnostics for predictive maintenance.

Use Value: Output short-to-GND/VS protection prevents failure from wet connector shorts; 15 µA standby current extends battery life during docked storage.

Use Scenario: Handlebar-mounted infotainment unit powering helmet speakers and rear speakers in vibration-prone motorcycle platforms.

IC Role / Device Role / Timing Role: Shock-tolerant audio amplifier with robust supply rejection (65 dB) to suppress ignition noise and alternator whine.

Use Value: 1 °C/W thermal resistance enables passive heatsinking on aluminum housing; diagnostics flag intermittent ground faults caused by vibration.

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 4×50 W output (4 Ω), improved THD (0.02%), but requires external compensation and larger heatsink.	Targeted at premium head units needing higher SPL; not pin-compatible due to different pinout and diagnostic logic.	Select when >42 W/channel is required and PCB layout allows added compensation components.
STA559BW	Digital input (I²S), Class D efficiency (85%), lower quiescent current (120 mA), but lacks analog diagnostics and clipping pulse output.	Suitable for DSP-based systems with digital audio sources; no analog input stage or SVR biasing network.	Choose for battery-powered portable audio or hybrid analog/digital architectures where efficiency >42 W/channel fidelity.

Compared with TDA7385, TDA7388 delivers higher power at the cost of increased complexity and thermal demand, while STA559BW trades analog diagnostics and simplicity for digital interface and efficiency - making TDA7385 optimal for cost-sensitive, analog-centric automotive head units requiring robust fault visibility.

Availability

TDA7385 is available at Aetrix Electronics and suitable for automotive head units, aftermarket stereo receivers, marine audio systems, and motorcycle infotainment hubs requiring stable component supply, long-lifecycle support, and AEC-Q200-aligned reliability.

Supply support for TDA7385 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 over 40 years of analog product heritage.

The TDA7385 belongs to ST's automotive audio amplifier product line, engineered specifically for high-fidelity, thermally robust, and diagnostics-rich Class AB amplification in space- and reliability-constrained vehicle infotainment systems.

FAQ

What is the maximum safe operating supply voltage for continuous use?

The TDA7385 supports continuous operation up to 18 V DC supply voltage. While it tolerates 50 V peak transients for 50 ms (load dump), sustained voltage above 18 V risks exceeding absolute maximum junction temperature and triggering irreversible thermal shutdown. Designers must ensure bulk capacitance and regulator headroom keep Vs within 14.4–16.5 V during normal operation to sustain 4×42 W output without derating.

How does the clipping detector output behave under mixed audio signals?

The clipping detector on Pin 16 emits discrete current-sinking pulses synchronized precisely to each clipping event across any channel - regardless of frequency or signal complexity. For multi-tone or music signals, pulse width matches the duration of saturation in the affected output transistor, enabling accurate RMS-based compression or dynamic range control without frequency weighting or averaging delays.

Can the TDA7385 drive 2 Ω loads per channel?

No - the TDA7385 is rated and protected only for 4 Ω minimum loads. Driving 2 Ω loads exceeds its safe operating area, causing excessive current (beyond 4.5 A repetitive peak) and rapid thermal accumulation. Even brief 2 Ω operation risks triggering thermal limiter or permanent damage due to insufficient SOA margin; ST does not characterize or guarantee performance below 4 Ω.

What is the role of Pin 12 (AC-GND) in noise rejection?

Pin 12 (AC-GND) serves as the common bias reference for all four amplifier inputs and is internally set to Vs/2. To reject common-mode noise, it must be connected to signal ground near the input coupling capacitors - not power ground - creating a low-impedance return path for differential input currents and improving PSRR by ≥15 dB compared to improper grounding.

TDA7385 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 25-Flexiwatt, Formed Leads

Packaging:: Tube

Product Status:: Obsolete

Type:: Class AB

Output Type:: 4-Channel (Quad)

Max Output Power x Channels @ Load:: 37W 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)

TDA7385 FAQ

1.How can I place an order for TDA7385 through Aetrix?

Please submit a Request for Quotation (RFQ) for TDA7385 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 TDA7385 reliable?

The price and inventory of TDA7385 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TDA7385 is usually 5 days.

3.What payment methods are accepted for TDA7385?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TDA7385 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TDA7385?

TDA7385 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TDA7385 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 TDA7385?

For technical support, including TDA7385 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TDA7385 requirements.

6.How does Aetrix verify that TDA7385 is sourced from the original manufacturer or authorized distributors?

All TDA7385 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 TDA7385 meets industry standards.

7.What is the process for return or replacement of TDA7385?

All TDA7385 units undergo pre-shipment inspection (PSI). If there is an issue with TDA7385, 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 TDA7385 part is unused and in its original packaging.

Return procedure for TDA7385:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…