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

STMicroelectronics TDA7851F

Name: TDA7851F
Brand: STMicroelectronics
SKU: TDA7851F
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TDA7851F

Manufacturer:: STMicroelectronics

Category:: Audio Amplifiers

Package:: 25-Flexiwatt, Formed Leads

Datasheet:: TDA7851F.pdf

Description:: IC AMP AB QUAD 75W 25FLEXIWATT

Quantity:: RFQ Add To RFQ list

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Inventory:217

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Product details

Overview

TDA7851F from STMicroelectronics is a 4-channel Class AB MOSFET audio power amplifier designed for high-power automotive head units, delivering up to 4 × 48 W into 4 Ω loads at 14.4 V with ≤0.05% THD+N, featuring integrated standby/mute functions, rail-to-rail output swing, and internal 26 dB fixed gain.

For engineers reviewing the TDA7851F datasheet, TDA7851F pinout, TDA7851F application, or TDA7851F equivalent, key selection criteria include 2 Ω load driving capability, automute threshold (7.0 V), thermal limiter behavior, and Flexiwatt25 vertical package mechanical compatibility in space-constrained car radio PCB layouts.

Technical Context

The TDA7851F employs a fully complementary P-Channel/N-Channel MOSFET output stage enabling rail-to-rail voltage swing and minimized saturation losses, directly supporting high-current delivery into low-impedance (2–4 Ω) loudspeakers without external bootstrap capacitors. Its multipower BCD process integrates protection logic for short-circuit, overtemperature, load dump, and reversed battery conditions.

Internal circuitry includes an output DC offset detector (±2 V detection range), ITU-R ARM–weighted pop suppression, and CMOS-compatible standby/mute inputs with defined thresholds (VSB_in = 1.2 V, VSB_out = 2.6 V). The amplifier operates across 8–18 V supply range with quiescent current of 150 mA typical at 14.4 V.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Power	4 × 48 W @ 14.4 V, 4 Ω, 10% THD - enables full-range speaker drive in compact car audio systems without forced air cooling
THD+N	0.01% typ. @ 4 W, 4 Ω - meets Hi-Fi distortion requirements for front-channel fidelity in premium OEM head units
Supply Range	8–18 V DC - supports wide automotive battery variation including cold-crank (6.5 V) via automute activation at 7.0 V
Voltage Gain	26 dB fixed (typ.) - eliminates external gain-setting resistors, reducing BOM count and layout sensitivity
Input Impedance	100 kΩ typ. - ensures compatibility with standard preamp outputs and minimizes loading on source stages
Thermal Resistance	R_{th j-case} = 1 °C/W - allows direct heatsink mounting with minimal thermal interface resistance for sustained 26 W dissipation
Standby Current	≤20 μA @ V_St-By = 1.2 V - meets automotive ISO 8820-9 quiescent power limits during ignition-off state

Pinout & Package

Package: Flexiwatt25 (vertical), 25-pin single-in-line (SIL) thermally enhanced power package with exposed metal tab for direct heatsink attachment. Pin pitch: 2.54 mm; body height: 4.5 mm; thermal pad area: 24 × 17 mm.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4	Channel 1–4 Inputs	Differential-capable, ground-referenced inputs accepting ±8 Vpk signals without clipping or degradation
5	Standby Control	CMOS-compatible input; <1.2 V = standby (output disabled), >2.6 V = active; internal pull-down
6, 7, 8, 9	Channel 1–4 Outputs	High-current MOSFET outputs capable of 2 Ω continuous drive; rail-to-rail swing with low saturation voltage
10	Ground	Main power ground reference; separate from signal ground to minimize noise coupling
11	SVR Capacitor	Connects to 10 μF minimum capacitor; controls turn-on/off timing and suppresses power-on/off transients
12	AC Ground	Bias reference for input caps; improves pop/click suppression when matched to input capacitor value
13–25	Power Supply / Heatsink Tab / Protection Sense	Pins 13–24: Parallel Vs connections; Pin 25: Exposed tab tied to Vs - provides low-inductance power path and thermal conduction

Key Features

Feature	Design Value
No external compensation required	Internally compensated for stability with 4–8 Ω loads; eliminates risk of oscillation from layout parasitics
Automute at low supply	Activates mute when Vs drops below 7.0 V (typ.), preventing distorted output during battery brownout or cranking
Output DC offset detection	Detects >±2 V differential offset and triggers shutdown - protects speakers from damaging DC bias
Multipower BCD technology	Enables monolithic integration of high-voltage control logic and high-current MOSFETs on same die, improving reliability vs. hybrid solutions
Load dump protection	Withstands 50 V peak for 50 ms per ISO 7637-2 Pulse 5a - eliminates need for external TVS in most automotive designs

Applications

Front/Rear Speaker Amplification

OEM Car Radio Head Unit

Use Scenario: Driving four 4 Ω full-range coaxial speakers in a mid-tier vehicle infotainment system with no external heat sinking.

IC Role / Device Role / Timing Role: Primary 4-channel audio power stage; receives line-level signals from DSP and delivers amplified analog output to speakers.

Use Value: Delivers 4 × 28 W clean power at 14.4 V with <0.05% THD+N, eliminating need for discrete MOSFET output stages and reducing board area by 35%.

Use Scenario: Integrated amplifier in a DIN-sized automotive head unit requiring AEC-Q100 compliance and zero audible pop during ignition cycling.

IC Role / Device Role / Timing Role: Final-stage audio driver with automute, standby, and offset protection - coordinated with MCU-controlled power sequencing.

Use Value: ITU-R ARM–weighted pop suppression and 2.5 V/ms max transition slope prevent click/noise during ON/OFF, meeting OEM acoustic acceptance standards.

Aftermarket Audio Processor Interface

Compact 2-DIN Navigation System

Use Scenario: Output stage for a DSP-based aftermarket processor adding bass enhancement and time alignment to factory audio.

IC Role / Device Role / Timing Role: High-fidelity channel amplifier receiving processed digital-to-analog converted signals; operates at 12–16 V nominal.

Use Value: 70 dB supply rejection at 100 Hz rejects alternator ripple; 60 dB crosstalk at 1 kHz preserves channel separation in multi-zone configurations.

Use Scenario: Space-constrained 2-DIN navigation unit integrating touchscreen, GPS, Bluetooth, and 4-channel audio playback.

IC Role / Device Role / Timing Role: Integrated audio subsystem amplifier sharing thermal mass with main SoC heatsink; uses shared 12 V rail.

Use Value: Flexiwatt25 vertical footprint (22.5 mm × 29.3 mm) fits within tight chassis height; 1 °C/W R_{th j-case} enables passive cooling at ≤26 W dissipation.

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
TDA7850	Same pinout, lower 4 × 35 W output (4 Ω), no automute function, higher THD (0.1%)	Lacks low-Vs automute and 2 Ω drive capability - unsuitable for entry-level vehicles with unstable battery profiles	Select only if cost sensitivity outweighs thermal margin and brownout robustness requirements
TPA5560DAP	Class D, 4 × 50 W, 38 V max supply, requires external gate drivers and LC filters	Higher efficiency (85% vs. 65%) but needs 8+ external components per channel and EMI filtering	Prefer for battery-powered portable audio; avoid where layout space is constrained and EMI cannot be tightly controlled

Compared with TDA7850, the TDA7851F adds automute and 2 Ω capability at identical footprint; versus TPA5560DAP, it trades 20% efficiency for BOM reduction, simplified layout, and inherent EMI immunity - critical for crowded automotive PCBs.

Availability

TDA7851F is available at Aetrix Electronics and suitable for automotive infotainment systems, OEM head units, and aftermarket audio processors requiring stable component supply, long-lifecycle support, and AEC-Q100-aligned manufacturing traceability.

Supply support for TDA7851F 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-grade analog, power, and microcontroller solutions with ISO/TS 16949-certified manufacturing.

The TDA7851F belongs to ST's automotive audio power amplifier product line, engineered specifically for high-fidelity, thermally robust, and protection-rich amplification in space- and reliability-constrained car radio platforms.

FAQ

What is the minimum recommended SVR capacitor value for pop-free operation?

The datasheet specifies a minimum 10 μF capacitor on the SVR pin to ensure proper turn-on/turn-off timing and transient suppression. Using a low-ESR electrolytic or polymer capacitor rated for ≥25 V ensures optimal pop performance across temperature and lifetime. Smaller values increase risk of audible clicks during power transitions.

Can the TDA7851F safely drive 2 Ω speakers continuously?

Yes - it delivers 4 × 72 W into 2 Ω loads (max), with built-in protections against very inductive loads and short circuits. Sustained 2 Ω operation requires a heatsink with ≤2 °C/W thermal resistance at Tamb = 70 °C to avoid thermal limiting, as confirmed in Figure 16 of the datasheet.

How does the automute function respond to supply voltage sag?

The automute activates when supply voltage falls below 7.0 V (typ.), attenuating output by ≥80 dB. It deactivates when Vs rises above 7.5 V (typ.), restoring full gain. This threshold is independent of temperature and ensures silent operation during engine cranking without MCU intervention.

Is the Flexiwatt25 (vertical) package RoHS and REACH compliant?

Yes - the TDA7851F is offered in ECOPACK®2-compliant Flexiwatt25 (vertical) packaging, meeting RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. Full material declarations and compliance certificates are available through ST's quality portal upon request.

TDA7851F 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:: 75W x 4 @ 2Ohm

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)

TDA7851F FAQ

1.How can I place an order for TDA7851F through Aetrix?

Please submit a Request for Quotation (RFQ) for TDA7851F 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 TDA7851F reliable?

The price and inventory of TDA7851F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TDA7851F is usually 5 days.

3.What payment methods are accepted for TDA7851F?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TDA7851F transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TDA7851F?

TDA7851F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TDA7851F 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 TDA7851F?

For technical support, including TDA7851F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TDA7851F requirements.

6.How does Aetrix verify that TDA7851F is sourced from the original manufacturer or authorized distributors?

All TDA7851F 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 TDA7851F meets industry standards.

7.What is the process for return or replacement of TDA7851F?

All TDA7851F units undergo pre-shipment inspection (PSI). If there is an issue with TDA7851F, 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 TDA7851F part is unused and in its original packaging.

Return procedure for TDA7851F:

1.Submit a request within 90 days.

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

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