TI中文支持网Part Number:TPA3223
＊Test Conditions：
1.Power is provided to the DUT (Net_PVDD & Net_5VP) by the DC power supply.
2.AMP Output(CH_1 & CH_2) connect to Loads(8 ohm).
3.Audio Precision Output(GND) connect to DUT_GND.
4.Use Audio Precision(AP-525) to measure.( Include AUX-0025)
I attach my circuit diagram & Equipment wiring diagram & gerber file. Pls. see below：
- Circuit diagram-1 (Equipment wiring diagram).pdf
- Circuit diagram-2 (Equipment wiring diagram)_No EMI Parts.pdf
- TPA3223 AMP PCB – Bottom Side.pdf
- TPA3223 AMP PCB – Top Side.pd
3872.Circuit diagram-1 (Equipment wiring diagram).pdf3872.Circuit diagram-2 (Equipment wiring diagram)_No EMI Parts.pdf6505.TPA3223 AMP PCB – Top Side.pdf6505.TPA3223 AMP PCB – Bottom Side.pdf
Current measurements show that THD+N is obviously on the high side overall. Various situations have changed, but the cause and solution have not yet been found. The conditions for change are as follows:
- BST capacitance (C47、C48、C49、C50)： Change from 33nF (EVM Board used value) to 220nF (Datasheet used value).
- Change PWM frame：Change R65 from 10k (PWM=480k Hz) to 50k ohm(PWM=600k Hz).
- Remove EMI Parts of AMP Output： Pls. see Circuit diagram-2 (Equipment wiring diagram)_No EMI Parts.pdf
PS Noise of DUT (ClassD AMP)：Measured value is about 130uV (AMP Gain 20dB). IC specs is 100uV. There is not much difference between the two.
The measurement curve of the above changes is similar to the following：
Measurement curve：POWER OUTPUT vs THD+N
In addition, the voltage of PVCC has been adjusted from 42V to 12V (24V / 39V / 45V).
(1) PVCC = 12V & 24V & 42V. Measurement curve：POWER OUTPUT vs THD+N
(2) PVCC = 39V & 42V & 45V. Measurement curve：POWER OUTPUT vs THD+N
But the distortion is also bed.
Can you give me some suggestions to improve this problem? Thank very much.
Amy Luo：
您好，
建议您将问题发布在E2E英文技术论坛上，请资深的英文论坛工程师为您提供帮助，英文论坛对应子论坛链接：
https://e2e.ti.com/support/audio-group/audio/f/audio-forum
,
JOE WANG：
感謝您的建議，已依照你所提供之連結來重新發布，謝謝
,
Amy Luo：
好的，不客气
