Class D amplifiers with real-time integrated speaker protection and audio processing capabilities

The Texas Instruments TAS2781 Class D amplifier is optimized for real-time integrated speaker protection and audio processing. The TAS2781 provides 25W continuous power to 4Ω loads at 18V supply voltage with THD+N less than 1%. The device has a wide voltage input range and high output power, making it ideal for use in battery or line powered systems.

TI TAS2781 Class D amplifier's on-chip DSP supports Texas Instruments Smart Amplifier speaker protection algorithm. Integrated speaker voltage and current detection allows real-time monitoring of the speaker. The Y-bridge power supply architecture improves amplifier efficiency by selecting the power supply internally for optimal margin. Undervoltage prevention schemes with adjustable thresholds reduce the gain in the signal path in the event of a voltage drop in the power supply.

The TAS2781 comes in a 30-pin HR-QFN package for compact PCB space occupying. The Hybrid-Pro algorithm allows users to optimize efficiency and extend battery life by controlling an external power source. Up to eight TAS2781 devices can share a common bus via the I2S/TDM and I2C/SPI interfaces.

Features

● Main characteristics
-   Integrated DSP for audio processing
-   23V power supply for Class D output stage
-   Y-bridge multilevel power supply architecture
-   Hybrid-pro external boost control algorithm
-   Ultrasonic output supports up to 40kHz

● Efficiency (1% THDN) and power consumption
-   82% when 1W, 4Ω, PVDDH = 12V, and PVDDL = 3.8V
-   83% when 1W, 8Ω, PVDDH = 18V, PVDDL = 5V
-   84% when 1W, 4Ω, PVDDH = 18V, PVDDL = 5V
-   90% when 15W, 4Ω, PVDDH = 18V, PVDDL = 5V
-   93% when 15W, 8Ω, PVDDH = 18V, PVDDL = 5V
-   Hardware off mode < 0.5 mu A

● Power supply and management:
-   1.8V AVDD
-   1.8V/3.3V IOVDD
-   2.7V to 5.5V PVDDL
-   PVDDH: 4.5V to 23V

● Output power:
-   25W, 1% THD+N (4Ω, 18V)
-   Maximum output power: 30W, 10pc THD+N

● Interface and control:
-   SDOUT for echo cancellation
-   I2S/TDM: 8 channels (32-bit), operating at 192KSPS
-   I2C interface or SPI interface with super fast mode
-   Interchip communication bus
-   Sampling rate: 16kHz to 192kHz

● Advanced DSP Audio processing:
-   Real-time IV-sense for speaker protection
-   Dynamic range compressor
-   Power loss protection with power limiter
-   Multi-channel balanced communication

● Protection and EMI:
-   Over power and low battery protection
-   PVDDH/PVDDL power tracing limiter
-   Thermal protection and overcurrent protection
-   Thermal reentry
-   Rear filter feedback and swing rate control

Applications

● Laptops and desktops
● Intelligent speaker
● Tablets and handheld devices
● Wireless speaker