2.1-channel high-efficiency digital audio system

The STA339BW is an integrated solution of digital audio processing, digital amplifier control, and FFX-power output stage, thereby creating a high-power single-chip FFX®solution comprising high-quality, high-efficiency, all digital amplification.

STA339BW is based on FFX (fully flexible amplification) processor, an STMicroelectronics proprietary technology. FFX is the evolution and the enlargement of the ST ternary technology: the new processor can be configured to work in ternary, binary, binary differential and phase shift PWM modulation schemes.

STA339BW contains the ternary, binary and binary differential implementations, a subset of the full capability of the FFX processor.

The STA339BW is part of the Sound Terminal®family that provides full digital audio streaming to the speaker, offering cost effectiveness, low power dissipation and sound enrichment.

The STA339BW power section consists of four independent half bridges. These can be configured via digital control to operate in different modes. 2.1 channels can be provided by two half bridges and a single full bridge, providing up to 2 x 9 W + 1 x 20 W of power output. Two channels can be provided by two full bridges, providing up to 2 x 20 W of power. The IC can also be configured as 2.1 channels with 2 x 20 W provided by the device and external power for FFX power drive.

Also provided in the STA339BW are a full assortment of digital processing features. This includes up to 8 programmable 28-bit biquads (EQ) per channel and bass/treble tone control. Available presets enable a time-to-market advantage by substantially reducing the amount of software development needed for certain functions. This includes audio preset volume loudness, preset volume curves and preset EQ settings. There are also new advanced AM radio interference reduction modes. Dual-band DRC dynamically equalizes the system to provide speaker linear frequency response regardless of the output power level. This feature independently processes the two bands, controlling dynamically the output power level in each band and so providing better sound quality.

The serial audio data input interface accepts all possible formats, including the popular I2S format. Three channels of FFX processing are provided. This high-quality conversion from PCM audio to FFX PWM switching waveform provides over 100 dB SNR and dynamic range.

Key Features

  • Wide voltage supply range
    • 5 V to 26 V (operating range)
    • 30 V (absolute maximum rating)
  • 3 power output configurations
    • 2 channels of ternary PWM (stereo mode) (2 x 20 W into 8 Ω at 18 V)
    • 3 channels - left, right using binary and LFE using ternary PWM (2.1 mode) (2 x 9 W + 1 x 20 W into 2 x 4 Ω, 1 x 8 Ω at 18 V)
    • 2 channels of ternary PWM (2 x 20 W) + stereo lineout ternary
  • 2.1 channels of 24-bit FFX® 100 dB SNR and dynamic range
  • Selectable 32 to 192 kHz input sample rates
  • I2 C control with selectable device address
  • Digital gain/attenuation +48 dB to -80 dB with 0.5 dB/step resolution
  • Soft volume update with programmable ratio
  • Individual channel and master gain/attenuation
  • Two independent DRC configurable as a dual-band anti-clipper (B2 DRC) or as independent limiters/compressors
  • EQ-DRC for DRC based on filtered signals
  • Dedicated LFE processing for bass boosting with 0.5 dB/step resolution
  • Audio presets:
    • 15 preset crossover filters
    • 5 preset anti-clipping modes
    • Preset night-time listening mode
  • Individual channel and master soft/hard mute
  • Independent channel volume and DSP bypass
  • Automatic zero-detect mute
  • Automatic invalid input-detect mute
  • 2-channel I2 S input data interface
  • Input and output channel mapping
  • Up to 8 user-programmable biquads per channel with 28-bit resolution
  • 3 coefficient banks for EQ presets storing with fast recall via I2 C interface
  • Bass/treble tones and de-emphasis control
  • Selectable high-pass filter for DC blocking
  • Advanced AM interference frequency switching and noise suppression modes
  • Selectable high- or low-bandwidth noise-shaping topologies
  • Variable max power correction for lower full-power THD
  • Selectable clock input ratio
  • 96 kHz internal processing sample rate, 24 to 28-bit precision
  • Thermal overload and short-circuit protection embedded
  • Video apps: 576 * fS input mode supported
  • Fully compatible with STA339BWS.

Circuit Diagram

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Technical Documentation

Product Specifications
Description Version Size
DS6004 DS6004: 2.1-channel high-efficiency digital audio system 8.0 1 MB
Application Notes
Description Version Size
AN4118 AN4118: APWLink USB interface board for Sound Terminal® demonstration boards 2.0 1 MB
AN3984 AN3984: IIR filter design equations for Sound Terminal® devices 1.1 493 KB
AN3340 AN3340: Loudspeaker characterization and compensation 1.3 3 MB
AN4569 AN4569: Using Sound Terminal® STA3xyBWz devices in 2.1 channel applications 1.0 2 MB
User Manuals
Description Version Size
UM1545 UM1545: Using the Audio Processor Workbench (APWorkbench) 1.0 3 MB

Publications and Collaterals

Description Version Size
APWorkbench software for audio ICs and MEMS microphones 1.0 2 MB
Description Version Size
Analog audio solution 1.0 1 MB
FFX - Full flexible amplification 4 MB
FFX Full flexible amplification 1.0 4 MB
Support & Community

Sample & Buy

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Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
STA339BWTR ActivePowerSSO 36IndustrialEcopack2 0 0

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.