TLV320DAC3100: Configuring the DAC in slave mode

Erblin Ujkani

Part Number: TLV320DAC3100

Hi, in my project I have microcontroller which generates an I2S transfer with all the necessary clocks (MCK, word-, and bit clock) to the TLVDAC.
I have read through the datasheet, but I don't quite understand the different clocks and prescalers mentioned there. Especially the PLL, MDAC, NDAC and the DOSR.
Is it necessary to configure these registers in this case of my project? If yes, how do I calculate them?

The data sent over I2S is 16 bit 44.1 KHz mono, and it's not necessary to send it through some DSP filtering.

-Erblin

over 8 years ago

0 Luis Fernando Rodriguez S. over 8 years ago

TI__Guru* 84915 points

Hi, Erblin,

These registers are important for the DAC3100 usage. Basically, you need to generate an internal sampling rate from the CODEC_CLKIN. You may select between many clock inputs (MCLK, GPIO1, BCLK) and use a PLL if necessary. This sampling rate must be the same than the WCLK frequency (44.1KHz in your case). So, the PLL coefficients and clock dividers must be configured to get DAC_fs = 44.1KHz in your application:

www.ti.com/.../tlv320dac3100.pdf

Please let me know if you have more questions or comments.

Best regards,
Luis Fernando Rodríguez S.

0 Erblin Ujkani over 8 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 160 points

Hi, thanks for answering. I have been trying to calculate the values in order to get DAC_fs = 44.1 KHz, but the closest I have come to is 45454.5 Hz, is this good enough? I have calulated with and without PLL.

-Erblin

0 Erblin Ujkani over 8 years ago in reply to Erblin Ujkani

Prodigy 160 points

New calculation gave me a closer result, 44191.92 Hz.

0 Luis Fernando Rodriguez S. over 8 years ago in reply to Erblin Ujkani

TI__Guru* 84915 points

Hi, Erblin,

I think that this value should be enough. In some cases, it is not possible to get the exact value. So, this sampling frequency would be correct since it doesn't have a high error percentage.

Best regards,
Luis Fernando Rodríguez S.

Audio

Audio forum

TLV320DAC3100: Configuring the DAC in slave mode