TAS6424EQ1EVM: TAS6424E-Q1 EVK Power Dissipation and Power Efficiency

Hi TI E2E Support,

Recently, I tried to measure the TAS6424E-Q1 power dissipation and efficiency. But the result is higher than the spec (TAS6424E-Q1 Datasheet Figure 7-7 & 7-8), so I want to check my steps to see if it is correct.

Power dissipation = Total Supply Power - Total Output Power

Power Efficiency = Total Output Power / Total Supply Power

Total Supply Power = Power Supply Current * Power Supply Voltage

Total Output Power = Plays a 1kHz tone and measures ALL channels' output power by Audio Precision.

Here is my setup :

Use TAS6424E-Q1 EVK

PVDD = 14.4V via Power Supply (Checked the EVK PVDD at 14.4V when the 1kHz Sine Tone was playing to avoid the line loss)

Input the 1kHz tone through USB.

Each output channel connects to a 4 ohms resistor.

Here are some of my test results :

1. Gain = 7.5V
   1. Supply Power = 14.4V * 2.558A = 36.84W
   2. Output Power = 25.90W
   3. Power Dissipation = 36.84 - 25.90 = 10.94W
   4. Power Efficiency = 25.90 / 36.84 = 70.3%
   5. Output Channel Measured THD+N <0.2%
2. Gain = 15V
   1. Supply Power = 14.4V * 6.85A = 98.64W
   2. Output Power = 80W
   3. Power Dissipation = 98.64-80 = 18.64W
   4. Power Efficiency = 80 / 98.64 = 81.1%
   5. Output Channel Measured THD+N <0.2%
3. Gain = 21V
   1. Supply Power = 14.4V * 6.82A = 98.21W
   2. Output Power = 79.9W
   3. Power Dissipation = 98.21 - 79.9 = 18.31W
   4. Power Efficiency = 79.9 / 98.21 = 81.4%
   5. Output Channel Measured THD+N <0.2%
4. Gain = 29V
   1. Supply Power = 14.4V * 6.93A = 99.79W
   2. Output Power = 81.48W
   3. Power Dissipation = 99.79 - 81.48 = 18.31W
   4. Power Efficiency = 81.48 / 99.79 = 81.7%
   5. Output Channel Measured THD+N <0.2%

Please help me to check the steps or provide your testing methods and steps.

If there is anything I can try, please let me know.

Best regards,

Jeffery.