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

3.2 Limiter Response

The settings for the Distortion Limiter validation, shown in Figure 3-3, can be programmed through direct I2C communication and are configurable in the PurePath™ Console 3 software.

Distortion Limiter PPC3 Configuration Figure 3-3 Distortion Limiter PPC3 Configuration

An example of the limiter actively adjusting the gain is represented in the scope capture of Figure 3-4. In this example, VBAT, provided by a bench top supply and represented on Channel two is ramped down over time causing the limiter to engage. Prior to the inflection point, the output signal on Channel one is a full-scale 2Vrms signal attenuated to approximately 120mVrms as VBAT drops.

Distortion Limiter Attack Profile Figure 3-4 Distortion Limiter Attack Profile

Figure 3-5 is an example of the attack and release rate of the limiter engaging as VBAT drops and suddenly ramps back to a level above the inflection point.

Distortion Limiter Two-Stage Response Figure 3-5 Distortion Limiter Two-Stage Response