SLAAEI4 August   2024 TAC5111-Q1 , TAC5212-Q1 , TAC5311-Q1 , TAC5312-Q1 , TAC5411-Q1 , TAC5412-Q1 , TAD5212-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Signal Processing Chain
  6. 3Distortion Limiter
    1. 3.1 Distortion Limiter Parameters
      1. 3.1.1 Threshold Maximum
      2. 3.1.2 Threshold Minimum
      3. 3.1.3 Inflection Point
      4. 3.1.4 Slope
      5. 3.1.5 Attack Rate
      6. 3.1.6 Release Rate
      7. 3.1.7 Hold Counter
    2. 3.2 Limiter Response
  7. 4Brown-Out Protection
    1. 4.1 Brown-Out Protection Parameters
      1. 4.1.1 Critical Level
      2. 4.1.2 Gain Level
      3. 4.1.3 Attack Rate
      4. 4.1.4 Release Rate
      5. 4.1.5 Hold Counter
    2. 4.2 Brown-Out Protection Response
  8. 5Thermal Foldback
    1. 5.1 Thermal Foldback Parameters
      1. 5.1.1 Temperature Threshold
      2. 5.1.2 Maximum Attenuation Threshold
      3. 5.1.3 Slope
      4. 5.1.4 Attack Coefficient
      5. 5.1.5 Release Coefficient
      6. 5.1.6 Hold Counter
        1. 5.1.6.1 Thermal Foldback Response
  9. 6Example
  10. 7Summary
  11. 8References

1 Introduction

Maximizing efficiency in battery-powered applications is paramount for extending battery life and maintaining high-quality audio. Audio signals that approach the limits of the dynamic range of the DAC can create distortion in the output signal and audio clipping. TAx5xxx-Q1 devices mitigate the risk of distortion and improve power consumption by allowing the user to map VBAT to the output peak because the device is continuously monitoring the output signal level with the limiter bank algorithm.

A droop in VBAT reduces the supply headroom needed to prevent audio clipping and the ability of the device to supply current is limited when the battery voltage continues to decrease. If an audio converter continues to drive significant current into a speaker, or speaker amplifier, the system battery voltage can dip below normal system operating levels. This continuous dip in voltage can potentially cause electrical damage to devices sharing the same supply, or result in the system shutting down. This type of event is commonly known as Brown Out. Texas Instruments' audio option for this problem is to incorporate a Brown-out Protector and Distortion Limiter to reduce the peak or gain of the output signal. These features grant the user control over attenuation levels based on supply voltage, which effectively manages device power consumption.

Automotive audio applications require that devices are fully-operational in high ambient temperature conditions. This device family has an overtemperature detection circuit that can enable the shutdown of input channels, MICBIAS, and on-chip boost in the DAC_FLT_CFG (P1_R80) and INT_CFG register (P0_R66) upon fault detection. The Thermal Foldback feature attenuates the audio signal based on a programmed temperature limit with audio playing to further prevent damage to the device.