8.4.2.4.3 Recommendations for Setting the Speaker Amplifier Gain Structure in Software Control Mode

1. Determine the maximum power target and the speaker impedance which is required for the application.
2. Calculate the required output voltage swing for the given speaker impedance which will deliver the target maximum power.
3. Chose the lowest analog gain setting via the A_GAIN[3:2] bits in the control port which will produce an output voltage swing higher than the required output voltage swing for the target maximum power.

NOTE

A higher gain setting can be used, provided the noise performance is acceptable and the power delivered to the speaker remains within the safe operating area (SOA) of the speaker, using the soft clipper if necessary to set the clip point within the SOA of the speaker.

4. Characterize the clipping behavior of the system at the rated power.
   • If the system does not produce the target power before clipping that is required, increase the analog gain.
   • If the system meets the power requirements, but clipping is preferred at the rated power, use the soft clipper or the digital clipper to set the clip point
   • If the system makes more power than is required but the noise performance is too high, consider reducing the analog gain.
5. Repeat Step 4 until the optimum balance of power, noise, and clipping behavior is achieved.