1 Introduction

The TAS2781 and TAS2783 devices are mono, digital input Class-D audio amplifiers optimized for efficiently driving high-peak power into small loudspeakers. The Class-D amplifier is capable of delivering 25 W of continuous power into a 4-Ω load with less than 1% THD+N at a supply voltage of 18 V. The broad voltage input range and the high output power makes this amplifier versatile enough to work with battery power or with line-powered systems. An on-chip low latency DSP supports Texas Instruments' SmartAmp speaker protection and audio enhancement algorithms. The integrated speaker voltage and current sense provides for real-time monitoring of loudspeakers, which permits pushing peak sound pressure levels (SPL) while keeping speakers from being damaged. The Y-Bridge power architecture improves amplifier efficiency by internally selecting the supplies for optimal headroom. The TAS2783 amplifier supports MIPI SoundWire v1.2, with SDCA.

The audio enhancement algorithms inside the TAS2781 and TAS2783 devices consist of volume control, equalizer filters, dynamic compressors, and some specialized functions such as psycho-acoustic bass enhancer, rattle noise suppressor, and posture control.

Figure 1-1 Audio Enhancement Signal Chain

The volume control is used to increase or decrease the intensity of the sound output. A soft ramp feature is supported so as to enable real-time updates without any audible distortion.

The equalizer filters are primarily used to provide a flat loudspeaker response and to extend the bass response.

The dynamic range compressors are used to compress loud signals and provide consistent loudness. The compressors use RMS-based signal-level tracking to control the power pumped into the speaker. The compressors can be applied at different audio frequency bands and can be independently configured.

The psycho-acoustic bass enhancer improves the bass perception by generating harmonics. The bass frequencies are removed to improve the efficiency of the loudspeaker but the bass perception remains the same due to the missing fundamental effect of psycho acoustics.

The rattle noise suppressor is a specialized algorithm that suppresses mechanical noise caused due to severe speaker rattle near resonance frequency.