Hello，
one customer used TAS5825PEVM for his application, but when music is playing, he can hear the music, but the speaker makes an intermittent hiss (which is louder than the music).
When the music stopped, so did the sizzling sounds.
The audio file I played is shown below
Then, he used my mobile phone to record the sound played from the speaker, as shown in the picture below:
He found that the noise is particularly obvious.
The speaker is 8Ω, 2W.
The situation is as this: He used the Battery on the TAS5825PEVM for power supply (5V) and do not use PVDD. The timing and frequency relationships of SCLK, BCK, and LRCK are correct. Now the board is very close to the mobile phone, and then the recording is recorded. When playing audio, noise can be heard. I compared and analyzed the spectrum of the recording file and the spectrum of the audio file, and found that the newly added frequency components in the recording file were concentrated in 0Hz~200HZ.
In addition, he didn't used the PPC3 for configuration, the configuration is as following:
Lower the analog gain and the effect will improve and the noise will become smaller, but still present.
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x03, 0x02 }, // HI-Z
{ 0x01, 0x11 }, // Reset Control Port Registers and Full Digital Core
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x03, 0x02 }, // HI-Z
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x03, 0x00 }, // Deep Sleep
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x46, 0x01 }, // 96kHz process flow
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x03, 0x02 }, // HI-Z
{ 0x00, 0x00 },
{ 0x7f, 0x00 },
{ 0x78, 0x80 }, // Fault clear (Not required, but recommended)
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0, Page 0
{ 0x60, 0x07 },
{ 0x61, 0x0b },
{ 0x62, 0x09 },
{ 0x63, 0x08 },
{ 0x00, 0x00 }, // Go to Page 0
{ 0x4e, 0xbb },
{ 0x4f, 0xb0 },
{ 0x02, 0x00 }, // BD, 384k BTL
{ 0x53, 0x00 }, // BW: 100k
{ 0x54, 0x1e }, // Amp Peak Output Voltage: 4.95V
{ 0x6B, 0x03 }, // Spread Spectrum: Triangle SS Enabled
{ 0x6C, 0x03 }, // Spread Spectrum: 24k, 25%, No Random/Dither
{ 0x6D, 0x50 }, // Spread Spectrum: Ensure Value is 0x50
{ 0x33, 0x17 }, // 32-bit TDM word
{ 0x3a, 0xf8 }, // DRBOOST Disabled
{ 0x50, 0x00 }, // Automute Disabled
{ 0x5f, 0x1e }, // Analog Gain Ramp
{ 0x00, 0x00 },
{ 0x7f, 0x00 }, // Go to Book 0,Page 0
{ 0x66, 0x87 }, // bypass DRC, EQ, 128 Tap FIR
{ 0x00, 0x00 },
{ 0x7f, 0x8c },
{ 0x00, 0x0b }, // Book 8C Page 0B
{ 0x14, 0x00 }, // Input mixer set to left channel only
{ 0x15, 0x80 },
{ 0x16, 0x00 },
{ 0x17, 0x00 },
{ 0x18, 0x00 },
{ 0x19, 0x00 },
{ 0x1a, 0x00 },
{ 0x1b, 0x00 },
{ 0x1c, 0x00 },
{ 0x1d, 0x00 },
{ 0x1e, 0x00 },
{ 0x1f, 0x00 },
{ 0x20, 0x00 },
{ 0x21, 0x80 },
{ 0x22, 0x00 },
{ 0x23, 0x00 },
{ 0x0c, 0x00 }, // volume control --Attenuation 40dB
{ 0x0d, 0x01 },
{ 0x0e, 0x47 },
{ 0x0f, 0xae },
{ 0x10, 0x00 },
{ 0x11, 0x01 },
{ 0x12, 0x47 },
{ 0x13, 0xae },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C Page 01
{ 0x00, 0x01 }, // Volume Time constant
{ 0x2c, 0x00 },
{ 0x2d, 0x71 },
{ 0x2e, 0x94 },
{ 0x2f, 0x9a },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C, page 0B
{ 0x00, 0x0b }, // AGL Section
{ 0x58, 0x00 },
{ 0x59, 0x00 },
{ 0x5a, 0x57 },
{ 0x5b, 0x62 },
{ 0x4c, 0x00 },
{ 0x4d, 0xcd },
{ 0x4e, 0x7b },
{ 0x4f, 0x90 },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C, page 0A
{ 0x00, 0x0a }, // Attack Threshold
{ 0x34, 0x05 },
{ 0x35, 0xb7 },
{ 0x36, 0xb1 },
{ 0x37, 0x5b },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C, page 01
{ 0x00, 0x01 }, // AGL Enable
{ 0x28, 0x40 },
{ 0x29, 0x00 },
{ 0x2a, 0x00 },
{ 0x2b, 0x00 },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C, page 0B
{ 0x00, 0x0b }, // Softening Filter Alpha
{ 0x48, 0x08 },
{ 0x49, 0x96 },
{ 0x4a, 0x57 },
{ 0x4b, 0x44 },
{ 0x00, 0x00 },
{ 0x7f, 0x8c }, // Book 8C, page 0B
{ 0x00, 0x0b }, // Softening Filter Omega
{ 0x54, 0x77 },
{ 0x55, 0x69 },
{ 0x56, 0xa8 },
{ 0x57, 0xbc },
{ 0x00, 0x00 },
{ 0x7f, 0x00 },
{ 0x30, 0x00 },
{ 0x4c, 0x30 },
{ 0x03, 0x08 },
// WARNING: nothing should be after this except clearing faults
{ 0x00, 0x00 }, // Go to Book 0, Page 0
{ 0x7f, 0x00 },
{ 0x78, 0x80 }, // Clear faults
Could you please help to analyze?
Best regards
kailyn
