• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 257 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TLV320AIC3104: rusty noise of headset

Lidong Yu
Intellectual 1756 points
Part Number: TLV320AIC3104

I’M USING TLC320AIC3104 AUDIO CODEC but during silence period I have a noisy into headset (a “rusty noise”):
MY I2S DATA are sampling frequency :16KHZ/ 16bits -sample
MY QUESTIONS ARE:
1) CAN I SET REGISTER 7 BIT 5 and BIT 6 to 1 in order to enable the “dual rate”?
2) What does it means “dual rate”? If it is to be referred to oversampling and decimation procedure inside codec, why it isn’t always “enabled”?
3) Is it only for 92Khz or also for all low frequencies? can I use this setting for every lower sampling rate as my case?

  • 0
    TI__Mastermind 29755 points

    Hi Lidong,

    This dual rate is referred to doubling the sampling rate as described in the datasheet below:

    1. You can set that if you want higher sampling rate.
    2. See above paragraph from datasheet, enable only if you want higher rate.
    3. If you want sampling higher than 48KHz then you can enable that.

    Regards,

    Peter

  • 0 in reply to pdjuandi
    TI__Intellectual 1756 points

    So, starting from the following setting: codec fsref= 48Khz/ 4,096MHz master clock, if we enable dual rate, the codec working sampling rate (that is fsref ) will be 96KHz, and then I just need to set REG2 with NCODEC=6 in order to set both ADC and DAC to final sampling rate of my data (that is 16KHz), or we need to change something else as compared to the fsref=48Khz?

    Do you think that in this manner (fsref=96KHz) in band noise would be less audible during "silence" time?

  • 0 in reply to Lidong Yu
    TI__Mastermind 29755 points

    Hi Lidong,

    fS(ref) is an internal rate as described below and should fall within 39KHz to 53KHz normally this is either 44.1KHz or 48KHz, when in dual-rate it's NOT fS(ref) becomes 96KHz but it's just multiplied by 2, fS(ref) is still 48KHz and the NCODEC will need to be 1 to get sampling rate of 96KHz. You use this dual rate if your actual sampling rate is above 48KHz, if 16KHz you don't need to use dual rate.

    Regards,

    Peter