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

STMicroelectronics FDA903D-EHX

Name: FDA903D-EHX
Brand: STMicroelectronics
SKU: FDA903D-EHX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FDA903D-EHX

Manufacturer:: STMicroelectronics

Category:: Audio Amplifiers

Package:: 36-PowerFSOP (0.295", 7.50mm Width)

Datasheet:: FDA903D-EHX.pdf

Description:: IC AMP D MONO 45W POWERSSO36

Quantity:: RFQ Add To RFQ list

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Inventory:4,593

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Product details

Overview

FDA903D-EHX from STMicroelectronics is a single-channel 45 W Class D digital-input automotive audio power amplifier, AEC-Q100 qualified for under-hood deployment. It integrates 108 dB D/A conversion, supports I²S/TDM (4/8/16-channel) digital input up to 192 kHz, and delivers 25 W into 4 Ω @ 14.4 V (THD = 1%) with built-in I_LOAD current monitoring - used in car radio head units and e-call telematics modules.

For engineers reviewing the FDA903D-EHX datasheet, FDA903D-EHX pinout, FDA903D-EHX application, or FDA903D-EHX equivalent, key selection criteria include wide 3.3–18 V supply operation, real-time load current sensing via I²C, CISPR 25 Class V compliance, thermal/short/open-load diagnostics in play mode, and legacy 'no-I²C' configuration support.

Technical Context

The FDA903D employs a closed-loop Class D architecture with integrated low-pass filter in the feedback path, enabling high-fidelity audio performance without external LC filtering. Its digital input interface accepts I²S or TDM streams at sampling rates of 44.1/48/96/192 kHz, with configurable channel count (4/8/16) and bit depth.

It implements a multi-layer diagnostic engine: DC offset detection (active in mute and play), short-to-VCC/GND detection, open-load detection during playback, four-tier thermal warning, clipping detection, and hot-spot identification via integrated current sensing. All diagnostics report via I²C registers with configurable thresholds.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Power	25 W @ 4 Ω, 14.4 V, 1 kHz, THD = 1% - sufficient for mid-range speaker drivers in compact automotive audio systems
Digital Input	I²S or TDM (4/8/16 CH), 16–32 bit, 44.1–192 kHz - supports multi-zone audio routing and high-res source integration
Supply Range	3.3 V to 18 V - enables direct connection to vehicle battery (including cold-crank down to 3.3 V) without pre-regulation
D/A Resolution	108 dB SNR - achieves >16-bit effective resolution for low-noise analog output stage fidelity
Diagnostic Coverage	Real-time open-load, short-circuit, thermal, DC offset, and PWM skipping detection - reduces need for external monitoring circuitry
Quiescent Current	≤ 20 mA @ 14.4 V - minimizes standby power draw in always-on telematics modules
CISPR 25	Class V compliant - meets stringent automotive EMC requirements for in-vehicle RF immunity and emissions

Pinout & Package

Package: PowerSSO-36 exposed pad (slug-down), RoHS-compliant, thermally optimized for automotive under-dash mounting with direct PCB copper pour thermal coupling.

Pin/Terminal	Circuit Role	Design Meaning
V_CC	Primary power supply input	Accepts 3.3–18 V; powers internal logic, gate drivers, and analog blocks - requires local 10 µF ceramic + bulk capacitance
V_OUT	Differential output terminal	Drives speaker load directly; configured as half-bridge with integrated MOSFETs - supports 2 Ω minimum load
I_SENSE	Current sense monitor output	Analog voltage proportional to load current (1 V/A); enables real-time I_LOAD monitoring without shunt resistor
SCL / SDA	I²C bus interface	Supports 3.3 V or 1.8 V logic levels; used for configuration, diagnostics readback, and power limiting control
MUTE	Hardware mute enable	Active-low pin; forces analog mute on falling edge and holds amplifier in low-power state - critical for noise-free startup/shutdown
FAULT	Open-drain diagnostic alert	Pulls low on thermal warning, short circuit, or open load - connects directly to MCU interrupt pin for system-level fault response

Key Features

Feature	Design Value
Integrated I_LOAD current monitoring	Eliminates external current-sense resistor and associated signal conditioning, reducing BOM count and board area in space-constrained head units
Play-mode open-load detection	Identifies disconnected speakers during active audio playback - prevents silent failure in safety-critical e-call voice paths
Configurable power limiter	Adjustable via I²C to cap output power dynamically (e.g., reduce thermal stress during high ambient temperature)
Legacy 'no-I²C' mode	Four preset configurations (gain, mute behavior, thermal threshold) selectable by hardware pins - simplifies integration in cost-sensitive designs
AM-compatible operation	Enables use in AM/FM radio modules without PWM interference due to optimized switching frequency and spread-spectrum modulation

Applications

Car Radio Head Unit

e-Call Telematics Module

Use Scenario: Integrated audio amplification in OEM infotainment head units with digital audio sources (Bluetooth, USB, tuner).

IC Role / Device Role / Timing Role: Single-channel Class D amplifier receiving I²S from SoC; handles full-range speaker drive with real-time diagnostics.

Use Value: Eliminates need for external DAC and analog amplification stages while maintaining AEC-Q100 reliability and CISPR 25 compliance.

Use Scenario: Voice amplification in emergency call (e-call) systems requiring guaranteed audio path integrity during crash events.

IC Role / Device Role / Timing Role: Audio output driver with continuous open-load and DC offset monitoring during active call - ensures speaker connectivity is verified in real time.

Use Value: Prevents silent failure of voice path; diagnostic alerts trigger system-level failover or audible alert before call initiation.

Telematics Control Unit (TCU)

Connected Rear-Seat Entertainment

Use Scenario: Audio output for navigation prompts, voice assistant feedback, and OTA update notifications in cellular-connected TCUs.

IC Role / Device Role / Timing Role: Low-quiescent-current amplifier operating across wide battery range (3.3–18 V), supporting cold-crank and stop-start cycles.

Use Value: Maintains functional audio during low-voltage transients (<4 V) without brownout reset - critical for driver-alert reliability.

Use Scenario: Compact audio amplifier for rear-seat tablets or displays with digital audio input and space-constrained PCB layout.

IC Role / Device Role / Timing Role: High-efficiency Class D driver with integrated thermal protection and 2 Ω load capability for small full-range speakers.

Use Value: Enables fanless design in plastic enclosures; exposed-pad PowerSSO-36 package dissipates heat directly to PCB ground plane.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Class D automotive amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TAS5756M from Texas Instruments	Higher channel count (2×45 W), but no integrated current sensing; requires external shunt and op-amp for I_LOAD monitoring	Targeted at multi-speaker systems; lacks play-mode open-load detection and legacy pin-strapped mode	Select when dual-channel output or higher integration with DSP is required; accept added BOM complexity for current monitoring
MAX9788 from Analog Devices	Lower output power (15 W @ 4 Ω), 96 dB SNR, no TDM support beyond stereo; supports only I²S and left-justified formats	Designed for entry-level audio nodes; missing CISPR 25 Class V certification and thermal warning granularity	Choose for cost-sensitive non-safety applications where 25 W output and advanced diagnostics are not mandatory

Compared with TAS5756M and MAX9788, FDA903D-EHX uniquely combines single-channel 25 W output, real-time I_LOAD monitoring, play-mode diagnostics, and pin-strapped legacy mode - making it optimal for compact, safety-aware automotive audio nodes where BOM reduction and diagnostic coverage are prioritized over multi-channel density.

Availability

FDA903D-EHX is available at Aetrix Electronics and suitable for car radio head units, e-call telematics modules, and connected TCU audio subsystems requiring stable component supply across extended automotive temperature and lifecycle requirements.

Supply support for FDA903D-EHX 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 specializing in automotive-grade ICs, with broad expertise in power management, analog, and embedded processing solutions.

FDA903D belongs to ST's automotive audio amplifier product line, engineered specifically for AEC-Q100-compliant digital-input Class D amplification in harsh-temperature, high-reliability vehicle environments - emphasizing diagnostic integrity, EMC robustness, and supply-voltage resilience.

FAQ

What is the minimum supply voltage for FDA903D-EHX operation?

The FDA903D-EHX operates down to 3.3 V, enabling reliable function during automotive cold-crank conditions. At this voltage, it delivers reduced output power (≈3 W into 4 Ω) with maintained THD and diagnostic functionality - verified per datasheet Section 5.3 and Figure 16–19.

Does FDA903D-EHX require an external LC filter?

No. The FDA903D-EHX uses an integrated feedback-based low-pass filter architecture that eliminates the need for external LC output filters. This reduces component count, board space, and EMI tuning effort while preserving audio fidelity - confirmed in Section 1 and Figure 1 block diagram.

How does the I_LOAD current monitoring work without a shunt resistor?

The FDA903D-EHX integrates a precision current-sense amplifier that measures voltage drop across its internal high-side MOSFET R_DS(on), producing a calibrated 1 V/A analog output on the I_SENSE pin. Accuracy is ±10% over temperature and supply range, per Table 5 electrical characteristics.

Can FDA903D-EHX drive 2 Ω loads continuously?

Yes - the device is rated for continuous 2 Ω load operation at 14.4 V, delivering up to 30 W (THD = 10%). Thermal protection and current limiting remain fully active; derating is only required above 85°C ambient, as specified in Table 4 thermal data and Figure 6–7 efficiency curves.

FDA903D-EHX Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 36-PowerFSOP (0.295", 7.50mm Width)

Packaging:: Tube

Product Status:: Active

Type:: Class D

Output Type:: 1-Channel (Mono)

Max Output Power x Channels @ Load:: 45W x 1 @ 2Ohm

Voltage - Supply:: 3.3V ~ 18V

Features:: I2C, I2S, Mute, Short-Circuit and Thermal Protection, Standby

Mounting Type:: Surface Mount

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: Automotive

Qualification:: AEC-Q100

Supplier Device Package:: PowerSSO-36 EPU

FDA903D-EHX FAQ

1.How can I place an order for FDA903D-EHX through Aetrix?

Please submit a Request for Quotation (RFQ) for FDA903D-EHX 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 FDA903D-EHX reliable?

The price and inventory of FDA903D-EHX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FDA903D-EHX is usually 5 days.

3.What payment methods are accepted for FDA903D-EHX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FDA903D-EHX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FDA903D-EHX?

FDA903D-EHX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FDA903D-EHX 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 FDA903D-EHX?

For technical support, including FDA903D-EHX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FDA903D-EHX requirements.

6.How does Aetrix verify that FDA903D-EHX is sourced from the original manufacturer or authorized distributors?

All FDA903D-EHX 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 FDA903D-EHX meets industry standards.

7.What is the process for return or replacement of FDA903D-EHX?

All FDA903D-EHX units undergo pre-shipment inspection (PSI). If there is an issue with FDA903D-EHX, 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 FDA903D-EHX part is unused and in its original packaging.

Return procedure for FDA903D-EHX:

1.Submit a request within 90 days.

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

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