SLVA824A January   2017  – July 2025 TAS6422-Q1 , TAS6424-Q1 , TAS6424L-Q1 , TPA3111D1-Q1 , TPA3221 , TPA3244 , TPA3245 , TPA3250 , TPA3251 , TPA3255 , TPA3255-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Overview
  6. 3Schematic and Design
    1. 3.1 Partial Diagnostic Circuits
    2. 3.2 Tuning the Circuit
    3. 3.3 Circuit Parameters
    4. 3.4 Operation
  7. 4Schematic and Bill of Materials
  8. 5Summary
  9. 6Revision History

2 Overview

This application note covers the design of external fault-diagnostic circuitry intended to differentiate between various short-circuit conditions and to provide speaker detection. The system being tested consists of the TPA3111D1-Q1 class-D amplifier driving an output speaker, with load-diagnostic circuitry attached in shunt across the speaker lines. While the TPA3111D1-Q1 is used as an example throughout this application note, this design is equally relevant for almost any class-D amplifier which lacks integrated fault diagnostics.