STMicroelectronics FDA803S-6DY

Overview

FDA803S-6DY from STMicroelectronics is a single-channel Class-D audio amplifier IC designed for automotive telematics and eCall systems, integrating a 24-bit/100 dB DAC, I²S/TDM digital input (up to 16 channels), PWM output stage with feedback before LC filter, and wide 3.3 V–18 V supply range. It delivers 10 W into 4 Ω at 14.4 V (1 kHz, THD = 1%) and supports diagnostic-in-play functionality including thermal warning, OCP, open-load detection, and clipping detection.

For engineers reviewing the FDA803S-6DY datasheet, FDA803S-6DY pinout, FDA803S-6DY application, or FDA803S-6DY equivalent, key selection criteria include AEC-Q100 qualification, QFN32 wettable flanks package, dual CD/Diag pins for real-time speaker diagnostics, configurable I²C address (2 options), and cranking-down capability to 3.3 V for start-stop engine operation.

Technical Context

The FDA803S employs a digital core with integrated PLL synchronized to the I²S/TDM bitstream clock, generating internal clocks for both digital processing and PWM switching at selectable frequencies (352.8/384/411.6/448 kHz). Its feedback-before-LC architecture enables compact demodulation filters and reduces BOM cost and board area.

Diagnostics operate continuously during playback: four thermal warnings, DC offset detection, over-current protection, open-load detection, and high-voltage mute are all configurable via I²C and reportable through two dedicated CD/Diag pins - one of which supports synchronization for EMC optimization across multi-device platforms.

Key Specifications

Pinout & Package

Package: QFN32 (5 mm × 5 mm × 1 mm, exposed pad down, wettable flanks, 3.5 mm × 3.5 mm thermal pad).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5411RTQR and MAX98740AETE+, FDA803S-6DY uniquely combines AEC-Q100 Grade 0, cranking to 3.3 V, feedback-before-LC, and dual CD/Diag pins - making it the only option qualified for production eCall modules requiring zero-failure speaker monitoring.

Availability

FDA803S-6DY is available at Aetrix Electronics and suitable for automotive telematics, eCall emergency systems, and driver-monitoring alert subsystems requiring stable component supply, long-lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for FDA803S-6DY 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 infrastructure.

FDA803S belongs to ST's automotive-grade Class-D amplifier product line, engineered specifically for safety-critical voice communication systems where reliability, diagnostics, and cranking resilience are mandatory - not general-purpose audio.

FAQ

What is the minimum supply voltage for FDA803S-6DY during cold-cranking?

The FDA803S-6DY operates down to 3.3 V, enabling uninterrupted audio output during automotive engine start-stop events where battery voltage dips below 6 V. This is verified per AEC-Q100 transient test profiles and confirmed in DB4683 Rev 3 Section 3.

Does FDA803S-6DY require an external LC filter, and what are typical values?

Yes - an external LC filter is mandatory between OUT1+/OUT1− and the speaker. Typical values per Figure 3 in DB4683 are L1 = 10 µH and C10 = 100 nF, optimized for 448 kHz PWM switching. Filter design must follow ST's layout guidelines to maintain CISPR 25 Class 5 compliance.

How are the CD/Diag pins configured for thermal warning reporting?

CD/Diag1 and CD/Diag2 are open-drain outputs configurable via I²C register 0x12 (DIAG_CFG). Each pin can be assigned one diagnostic function - e.g., CD/Diag1 = Thermal Warning #2, CD/Diag2 = Clipping Detection - allowing independent MCU GPIO monitoring without polling.

Is FDA803S-6DY pin-compatible with earlier ST Class-D amplifiers like FDA2100?

No - FDA803S-6DY uses a 32-pin QFN with unique pin mapping (e.g., dual Enable inputs, two CD/Diag outputs, separated VCC/GND rails) and is not pin-compatible with FDA2100 (HTSSOP20) or FDA200 (QFN24). Board redesign is required for migration.