STMicroelectronics STA333BWJ13TR

Overview

STA333BWJ13TR from STMicroelectronics is a 2.1-channel, 40 W high-efficiency digital audio system-on-chip (Sound Terminal®) integrating ternary/binary PWM amplification, FFX™ modulation, 96 kHz internal DSP processing, I²C control, and configurable audio presets. It delivers 2 × 9 W into 4 Ω + 1 × 20 W into 8 Ω in 2.1 binary mode at 18 V, with 100-dB SNR, dynamic range compression, and thermal/short-circuit protection. Used in compact stereo soundbars and active subwoofer systems requiring integrated digital audio processing and Class-D output.

For engineers reviewing the STA333BWJ13TR datasheet, STA333BWJ13TR pinout, STA333BWJ13TR application, or STA333BWJ13TR equivalent, key selection considerations include its 2.1-channel binary/ternary PWM output flexibility, 32–192 kHz I²S input support, programmable biquad EQ (5 per channel), selectable noise-shaping topology, and PowerSSO-36 EPD thermal package compatibility with STA335BW/STA339BW.

Technical Context

The STA333BWJ13TR implements ST's FFX™ (Full Flexibility eXtended) modulation architecture with scalable modulation index and selectable high-/low-bandwidth noise-shaping topologies to optimize EMI and audio fidelity. Its 96 kHz internal processing engine supports up to 5 user-programmable biquad filters per channel across three coefficient banks for fast EQ preset recall via I²C.

It integrates dual-domain signal paths: a digital audio front-end with I²S interface, sample-rate conversion (32–192 kHz), channel mapping, and de-emphasis; and a power stage with ternary or binary PWM outputs, subchannel mixing, and automatic invalid-input mute. Protection includes thermal overload detection with programmable recovery, short-circuit shutdown, and AM interference suppression via frequency switching.

Key Specifications

Pinout & Package

STA333BWJ13TR uses the PowerSSO-36 EPD (Exposed Pad Down) package - a thermally enhanced 36-pin surface-mount package with an exposed thermal pad on the underside for direct PCB copper pour attachment, enabling efficient heat dissipation in high-power audio applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2.1-channel digital audio system applications.

Compared with STA335BW and STA339BW, the STA333BWJ13TR offers optimal cost/performance balance for fixed 2.1-channel consumer audio - retaining full FFX™ performance, EQ flexibility, and thermal robustness while omitting higher-channel-count or video-specific features.

Availability

STA333BWJ13TR is available at Aetrix Electronics and suitable for soundbar manufacturing, active subwoofer production, and smart speaker development requiring stable component supply and long-term industrial availability.

Supply support for STA333BWJ13TR 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, designing and manufacturing microcontrollers, analog ICs, power management, and audio solutions for industrial, automotive, and consumer markets.

The STA333BWJ13TR belongs to ST's Sound Terminal® family - engineered specifically for space-constrained, high-efficiency digital audio systems where integration of processing, control, and Class-D amplification reduces system cost and design cycle time.

FAQ

What are the supported I²S input formats and clocking configurations?

The STA333BWJ13TR supports I²S, left-justified, and right-justified formats with MSB-first or LSB-first data ordering, selectable via register bits. It accepts master or slave BCLK/LRCK modes, with programmable clock ratio (128× to 512× fS) and delay-adjustable serial clock enable - enabling interoperability with diverse SoCs and audio codecs without external level shifters or clock buffers.

How does the thermal protection mechanism operate, and can it be configured?

Thermal protection triggers at ~150°C die temperature, asserting the open-drain THERM pin and initiating soft shutdown of PWM outputs. Recovery is automatic after die cooling below ~135°C, with bypass options configurable via registers (thermal warning recovery and adjustment). No external components are needed - the behavior is fully register-controllable for system-level thermal policy enforcement.

Can the STA333BWJ13TR drive 4 Ω and 8 Ω loads simultaneously in 2.1 mode?

Yes - in 2.1 binary PWM mode, the left/right channels deliver 2 × 9 W into 4 Ω loads (BTL), while the subwoofer channel delivers 1 × 20 W into an 8 Ω load (BTL), all from a single 18 V supply. The output stage is internally configured for independent channel impedance handling, eliminating need for external impedance-matching networks or separate power rails.

Is there hardware support for pop/click suppression during power-up and power-down?

Yes - the device implements a controlled power-on/off sequence with internal ramping of bias voltages and output stage enable timing, documented in Figures 4 and 5 of the datasheet. Combined with soft volume update and zero-crossing mute (configurable via register), this eliminates audible transients during system startup, standby entry, and source switching - no external muting circuitry required.