(ACTIVE) Digital Input 2.8 W Class-D Audio With Class-D Boost And Speaker Sense


Functional Diagram


The TAS2553 is a high efficiency Class-D audio power amplifier with advanced battery current management and an integrated Class-G boost converter. The device constantly measures the current and voltage across the load and provides a digital stream of this information.

The Class-G boost converter generates the Class-D amplifier supply rail. During low Class-D output power, the boost improves efficiency by deactivating and connecting VBAT directly to the Class-D amplifier supply. When high power audio is required, the boost quickly activates to provide significantly louder audio than a stand-alone amplifier connected directly to the battery.

The AGC automatically adjusts Class-D gain to reduce battery current at end-of-charge voltages, preventing output clipping, distortion and early system shutdown. The fixed gain is adjustable via I2C. The gain range is –7 dB to +24 dB in 1 dB steps.

In addition to a differential mono analog input, the TAS2553 has built-in a 16-bit D/A converter used with a digital input. Moving the D/A converter from the digital host processor into the integrated amplifier process provides better dynamic performance at lower system cost. Additionally, since the PCB routing is digital rather than analog, sensitivity to external perturbations such as GSM frame-rate noise is decreased at the system level.


  • Analog or Digital Input Mono Boosted Class-D Amplifier
  • 2.8 W into 8 Ω Load from 3.6 V Supply (1% THD+N)
  • Efficiency of 86% at Rated Power
  • I2S, Left-Justified, Right-Justified, DSP, PDM, and TDM
    Input and Output Interface
  • Input Sample Rates from 8 kHz to 192 kHz
  • High Efficiency Class-G Boost Converter
    • Automatically Adjusts Class-D Supply
  • Built-In Speaker Sense
    • Measures Speaker Current and Voltage
    • Measures VBAT and VBOOST Voltages
  • Built-In Automatic Gain Control (AGC)
    • Limits Battery Current Consumption
  • Adjustable Class-D Switching Edge-Rate Control
  • Power Supplies
    • Boost Input: 3.0 V to 5.5 V
    • Analog: 1.65 V to 1.95 V
    • Digital I/O: 1.5 V to 3.6 V
  • Thermal and Short-Circuit Protection
  • I2C Interface for Register Control
  • Stereo Configuration Using Two TAS2553s
    • I2C Address Select Terminal (ADDR)
  • 2.855 mm × 2.575 mm, 0.4 mm Pitch 30-Ball WCSP


Audio Input Type Analog Input^Digital Input    
Architecture Class-D Boosted    
Speaker Channels (Max) Mono    
Power Stage Supply (Min) (V) 2.7    
Power Stage Supply (Max) (V) 5.5    
Output Power (W) 2.8    
Load (Min) (ohms) 6    
SNR (dB) 94    
THD + N @ 1 kHz (%) 0.9    
Iq (Typ) (mA) 7.1    
Control Interface I2C    
Closed/Open Loop Closed    
Analog Supply (V) (Min) 2.7    
Analog Supply (V) (Max) 5.5    
Sampling Rate (Max) (kHz) 192    
PSRR (dB) 75    
Operating Temperature Range (C) -40 to 85    
Rating Catalog    

Companion Products

Technical Documents

Datasheet (1)

Application notes (3)

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