TAS5538 Arbitrary Delay Settings using Biquad Filter

Sadanori Kato

Other Parts Discussed in Thread: TAS5538

Hi,

We would like to implement the arbitrary delay function to TAS5538 using the biquad filter.
For example, we believe that it is realized by applying the coefficients of the equiripple linear phase low pass filter.
Thus, could you please tell us the procedure to design it in details?
The designing conditions are shown as below.

<Designing Conditions>
fs : 44.1kH, 48kHz, 96kHz
Delay Time Settings : 40us, 60us, 80us
fc : not specified(the priority is the delay.)

Could you please give us your advice to implement it if not possible?

Best Regards,
Kato

over 9 years ago

0 Don Dapkus over 9 years ago

TI__Guru**** 189399 points

Hi, Kato-san,

We will work with you on this issue.

-d2

0 Sadanori Kato over 9 years ago in reply to Don Dapkus

Guru 36490 points

Hi Don-san,

Thank you for your reply.
I am looking forward to hearing your advice.

Best Regards,
Kato

0 Sadanori Kato over 9 years ago in reply to Sadanori Kato

Guru 36490 points

Hi Don-san,

I am considering as below since the biquad filter structure is mentioned in the data sheet.
If the unit of 1/fs as the delay quantity is permitted, I believe that it can be implemented.
could you please give me your advice if I have any misunderstanding?

1. 1/fs Delay Settings
b0=0
b1=1
b2=0
a1=0
a2=0

2. 2/fs Delay Settings
b0=0
b1=0
b2=1
a1=0
a2=0

Best Regards,
Kato

0 Tuan over 9 years ago in reply to Sadanori Kato

TI__Mastermind 33420 points

Hi Kato-san:

Are you implementing an FIR or an IIR filter?

Best regards,

Tuan

0 Sadanori Kato over 9 years ago in reply to Tuan

Guru 36490 points

Hi Tuan-san,

Thank you for your quick response.
I believe that I should be adopted the FIR if the equiripple linear phase low pass filter is implemented, however it is difficult to realize it with the full audio signal band in this case since the number of the tap is not enough.
Therefore, could you please give me your advice whether the delay of 1/fs or 2/fs is able to realize simply by using the coefficients of b1 or b2 only ?
Would you tell me the other method simply if it is not possible ?

Best Regards,
Kato

0 Tuan over 9 years ago in reply to Sadanori Kato

TI__Mastermind 33420 points

Hello Kato-san:

Yes, you are correct. Direct form I is best suited for IIR. FIR only has 7 taps. To delay 1 sample set b1 = 1 ; to delay 2 samples set b2 = 1. I think you stated this in your previous post.

Best regards,

Tuan

0 Sadanori Kato over 9 years ago in reply to Tuan

Guru 36490 points

Hi Tuan-san,

Thank you for confirming.
I will inform our customer of this information.

Best Regards,
Kato

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TAS5538 Arbitrary Delay Settings using Biquad Filter