TLV320AIC23: Headphones have current noise

Hi,

I'm not exactly clear of the description above, so let's start with the following:

• Is the codec slave or master? Are you doing a playback (DAC) to headphone output?
• Can you capture the LRCIN, BCLK?
• Can you provide your register settings?
• Do you see issue if you do a loopback as shown below?

Regards,

Peter

Hi Peter,

Thank you for your help.

1. The encoder is the host, and there will be noise whether output or not.

2. The external crystal oscillator of the decoder is 12M. Then use an oscilloscope to measure the frequency of lrcin pin is 44.1KHz, and the frequency of BCLK is 12Mhz.

3. Settings:

AIC23Write(0x00,0x17);

Delay(100);

AIC23Write(0x02,0x17);

Delay(100);

AIC23Write(0x04,0xf9);// 0x7a

Delay(100);

AIC23Write(0x06,0xf9);// 0x7f

Delay(100);

AIC23Write(0x08,0x72);// 0x1a

Delay(100);

AIC23Write(0x0A,0x00);

Delay(100);

AIC23Write(0x0C,0x00);

Delay(100);

AIC23Write(0x0E,0x43);

Delay(100);

AIC23Write(0x10,0x23);

Delay(100);

AIC23Write(0x12,0x01);

Delay(100);

4. According to the circuit settings provided by you, there is noise. The following picture has the problem of noise whether it is set to 0 or 1.

Thanks a lot.

Best regards,

Hi,

Can you help verify the registers again? It does not look right per the register map in the datasheet.

See my comments in the attached sheet.

Register.xlsx

You should enable the LINE input and use bypass to send the output to LINE output first to confirm the audio quality.

Regards,

Peter

Hi Peter,

OK, thank you for your answer,

I have two questions:

1. Whether the filtering part of the schematic diagram is correct?

2. Our register is written according to the data manual of 23B. I don't understand the incorrect part you refer to, or do you have a general reference?

Best regards,

Hi,

1. That's fine.

2. Here are few clarification I need from your registers above:

• When you write AIC23Write(0x00,0x17), is this register address (0x00) follow by data (0x17)?
• In the datasheet section 3.1.3 the register map starts from address 0x00 to 0x0F, but your registers ends at 0x12. 

• Your registers only set the even registers and the data values don't seem to match your test path. Can you clarify and explain how do you set the register and its data?
• In the register map, the register has 9 bits data for example shown below and yours is only 8 bit data.

Maybe we are looking at different datasheet, can you clarify?

Regards,

Peter

Dear,

1. We use I2C to send, I2c is 8bit to send, but the register address is 7bit, so we did a shift (left shift 1bit) before sending the code,
0000000 -> 1bit left shift -> 0000000
0000001 -> shift left 1bit -> 0000002
0000002 -> shift left 1bit -> 0000004
0000003 -> 1bit left shift -> 0000006
0000004 -> 1bit left -> 0000008
0000005 -> shift left 1bit -> 000000a
0000006 -> 1bit left -> 000000c
0000007 -> 1bit left -> 000000e
0000008 -> 1bit left -> 0000010
0000009 -> 1bit left -> 0000012
000000f -> shift left 1bit -> 000001e

2. The register value is 9bit, but I only use 8bit here, and we have no configuration for the highest bit
Do you have the correct register configuration? Send me a copy. If there is any MCBSP configuration, send me a copy. Let’s refer to the timing configuration. We use 16bit. Let’s refer to it. Thank you