TAS2781 Speaker-Protection Class D Amp

Texas Instruments' mono digital input amp features real-time integrated speaker protection and audio processing

Image of Texas Instruments' TAS2781 Speaker-Protection Class D Amp (click to enlarge)Texas Instruments' TAS2781 is a mono digital input Class D audio amp that is optimized for efficiently driving high peak power into loudspeakers. The Class D amp can deliver 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 make this amp suitable for battery or line-powered systems. An on-chip DSP supports Texas Instruments' smart amp speaker-protection algorithm.

The integrated speaker voltage and current sense enable real-time monitoring of loudspeakers. The Y-bridge power architecture improves the amp efficiency by internally selecting the supplies for optimal headroom. The brownout prevention scheme with an adjustable threshold allows for gain reduction in a signal path when the supply drops. The hybrid-pro algorithm allows the user to optimize the efficiency and improve the battery life by controlling the external power supply. Up to eight TAS2781 devices can share a common bus via the I2S/TDM and I2C/SPI interfaces. The TAS2781 is available in a 30-pin HR-QFN package for a compact PCB footprint.

Features
  • Integrated DSP for audio processing
  • Supply: 23 V for Class D output stages
  • Y-bridge multi-level supply architecture
  • Ultrasonic output support: up to 40 kHz
  • Output power:
    • 25 W and 1% THD+N (4 Ω, 18 V)
    • 30 W (max.) and 10% THD+N
  • Efficiency (1% THD+N) and power consumption:
    • 82% at 1 W, 4 Ω, PVDDH = 12 V, and PVDDL = 3.8 V
    • 83% at 1 W, 8 Ω, PVDDH = 18 V, and PVDDL =5 V
    • 84% at 1 W, 4 Ω, PVDDH = 18 V, and PVDDL = 5 V
    • 90% at 15 W, 4 Ω, PVDDH = 18 V, and PVDDL = 5 V
    • 93% at 15 W, 8 Ω, PVDDH = 18 V, and PVDDL = 5 V
    • <0.5 μA in hardware shutdown mode
  • Power supplies and management:
    • AVDD: 1.8 V
    • IOVDD: 1.8 V and 3.3 V
    • PVDDL: 2.7 V to 5.5 V
    • PVDDH: 4.5 V to 23 V
  • Hybrid-pro external boost control algorithm
  • Interfaces and control:
    • SDOUT for echo cancellation
    • I2S/TDM: 8 channels of 32 bits to 192 KSPS
    • I2C with fast mode+ or an SPI interface
    • Inter-chip communication bus
    • Sample rate range: 16 kHz to 192 kHz
  • Advanced DSP audio processing:
    • Real-time IV-sense for speaker protection
    • Dynamic range compressor
    • Brownout protection with a power limiter
    • Multi-channel balancing communication
    • Protection and EMI:
      • Overpower and low-battery protection
      • PVDDH/PVDDL supply tracking limiters
      • Thermal and overcurrent protections
      • Thermal foldback
      • Post-filter feedback and slew-rate control
Applications
  • Laptops and desktop computers
  • Smart speakers
  • Tablets and handhelds
  • Wireless speakers

TAS2781 Speaker-Protection Class D Amp

ImageManufacturer Part NumberDescriptionAmplifier TypeNumber of CircuitsOutput TypeAvailable QuantityPriceView Details
QUAD, 36-V, 1.2-MHZ, 3-MV OFFSETLM324BIPWRQUAD, 36-V, 1.2-MHZ, 3-MV OFFSETStandard (General Purpose)4Push-Pull5681 - Immediate$0.23View Details

Evaluation Board

ImageManufacturer Part NumberDescriptionAmplifier TypeOutput TypeMax Output Power x Channels @ LoadAvailable QuantityPriceView Details
EVAL BOARD FOR TAS2781TAS2781EVMEVAL BOARD FOR TAS2781Class D1-Channel (Mono)25W x 1 @ 4Ohm5 - Immediate$358.80View Details
Published: 2023-05-02