High Fidelity 175-W Class-D Audio Amplifier with Digital Inputs and Processing Reference Design


Design files


This design turns the extremely high performance analog input TPA3251 Class-D amplifier into a digital input system with audio processing using the highly versatile PCM5242 differential output DAC. Now the full performance of TPA3251 amplifier can be realized with a variety of digital input sources. The analog differential output and high SNR of the PCM5242 DAC is a perfect match to the fully differential analog input of the TPA3251 amplifier achieving outstanding noise performance and extremely low distortion. With the miniDSP on the PCM5242, audio processing and filtering can be added to further enhance audio performance in the end equipment.

  • High performance and audio fidelity from the TPA3251 with digital sources
  • Accepts USB, Optical, SPDIF and I2S format digital inputs
  • 175W @ 10% THD + N from digital sources
  • Less than 0.004% THD + N 10W into 4ohms
  • miniDSP processing flexibility with PCM5242 DAC
  • Fully differential analog path for noise rejection
??image.gallery.download_en_US?? View video with transcript Video

A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.


Test results for the reference design, including efficiency graphs, test prerequisites and more

TIDRJX2.PDF (1223 K)

Detailed schematic diagram for design layout and components


Complete listing of design components, reference designators, and manufacturers/part numbers


Detailed overview of design layout for component placement

TIDRJX6.ZIP (2132 K)

Files used for 3D models or 2D drawings of IC components

TIDCBP2.ZIP (1764 K)

Design file that contains information on physical board layer of design PCB


PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Speaker amps

TPA3251175-W stereo, 350-W mono, 12- to 38-V supply, analog input Class-D Smart Audio Amplifier

Data sheet: PDF | HTML
Audio DACs

PCM52424.2-VRMS DirectPath™, 32-bit, 384-kHz, 114-dB Audio Stereo DAC

Data sheet: PDF | HTML
Buck converters (integrated switch)

LM5010A6-75V Wide Vin, 1A Constant On-Time Non-Synchronous Buck Regulator

Data sheet: PDF | HTML
Linear & low-dropout (LDO) regulators

LM2940-N1-A, 26-V, high-PSRR, low-dropout voltage regulator

Data sheet: PDF | HTML
Linear & low-dropout (LDO) regulators

TPS736400-mA, high-accuracy, ultra-low-dropout voltage regulator with reverse current protection & enable

Data sheet: PDF | HTML
Sample rate converters

SRC4392High-end Combo Sample Rate Converter

Data sheet: PDF

Technical documentation

= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 7
Type Title Date
* Test report TIDA-00874 Test Results Dec. 18, 2015
More literature High-Power Audio Amplifiers TPA322x/4x/5x Dec. 01, 2017
Technical article How Class-D amplifiers are closing the gap on hi-res Class-AB amplifiers Apr. 01, 2016
Technical article How to select an audio amplifier for products with internal or external speakers Feb. 29, 2016
Technical article Selecting the right inductor for ultra-low distortion Class-D audio amplifiers Jan. 29, 2016
Technical article Setting the new standard: High-definition audio is changing the way we listen Dec. 22, 2015
User guide Using the TAS5754/6M and PCM5242 HybridFlow Processor (Rev. A) Jun. 19, 2015

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​