[FAQ] TAS2563: Speaker cannot heat up properly during thermal characterization

It is important to be able to properly model the thermal response of the speaker for the reliability of the Smart Amp Protection algorithm. Depending on the built and material of speaker, each speaker has different thermal parameters such as the temperature limit, excursion limit, thermal coefficient, and etc. Therefore, it is important to verify that these values are correctly entered in the PPC3.

During the thermal modeling process, users can also adjust controller parameters to resolve most of the issues encountered.

If the speaker is not able to heat up properly, user can try the following:

1. Adjust the controller gain to a higher level. This will increase the power output to heat up the speaker
2. Decrease the excitation frequency from 16 kHz to a lower frequency (e.g. 3 kHz)
3. Try a lower delta but tolerable delta Celsius. Because every speaker respond differently, it is best to test the delta Celsius for the speaker for several runs(below/above or near Tmax). If Tmax is 90 C and ambientt is 20 C, try delta C of 60-65 C.
4. Give enough time for the coil to cool between each run

If the speaker thermal model is oscillatory, user can try the following:

1.  Reduce the "Controller gain" to a lower level
2.  Increase the "Controller Settling Correction"
3.  Try a lower delta but tolerable delta Celsius. Because every speaker respond differently, it is best to test the delta Celsius for the speaker for several   runs(below/above or near Tmax). If Tmax is 90 C and ambientt is 20 C, try delta C of 60-65 C.
4.  Give enough time for the coil to cool between each run

Each Parameter is explained as listed below:

• “Ambient temperature” can be changed to the room temperature which the device is under testing.
• “Max. delta temperature” was defined previously in the Safe Operating Area tab as “ΔThermal Limit”
• Min. and Max duration define the runtime of the thermal measurement test and should be left in default values.
• For larger speakers, the “Controller setting correction” and “Controller Gain” may need to be increased. For example, for speakers with power rating of 1 W, use a controller gain of 0.01, and for speakers with power rating between 2 W to 3 W, change the controller gain to 0.03
• Thermal Fit Offset is usually set as default.
• In case of oscillatory behavior during temperature test, it is recommended to run with lower controller gain for a more stable response.
• In order to properly test the thermal characteristic, please wait at least 30 minutes before performing the thermal characterization test again on the same speaker unit. This will ensure the speaker coil has time to cool down and reach ambient temperature.